Anaximander was a pre-Socratic Greek philosopher from Miletus who lived from around 610-546 BC. He was a student of Thales and succeeded him as the leader of the Milesian school of philosophy. Anaximander is considered one of the first scientists and philosophers in the Western world. He developed early theories of cosmology, including that the Earth is cylindrical and floats stationary at the center of the infinite universe. He also speculated that other worlds could exist and proposed the first non-mythological explanation of the universe's origins from an indefinite primordial substance called the apeiron.

1. Anaximander
From Wikipedia, the free encyclopedia
This article is about the Pre-Socratic philosopher. For other uses, see Anaximander (disambiguation).
Anaximander (Ἀναξίμανδπορ)
Detail of Raphael's painting The School of Athens, 1510–1511. This could
be a representation of Anaximander leaning towards Pythagoras on his
left.[1]
Full name Anaximander (Ἀναξίμανδπορ)
Born c. 610 BC
Died c. 546 BC (aged around 64)
Era Pre-Socratic philosophy
Region Western Philosophy

2. School Ionian Philosophy, Milesian school, Naturalism
Main interests Metaphysics, astronomy,geometry, geography
Notable ideas The apeiron is the firstprinciple
Influenced by[show]
Influenced[show]
Anaximander /əˌnæksɨˈmændər/ (Greek: Ἀναξίμανδπορ, Anaximandros; c. 610 – c. 546 BC) was a pre-
Socratic Greek philosopher who lived in Miletus, a city of Ionia; Milet in modern Turkey. He belonged to
the Milesian school and learned the teachings of his master Thales. He succeeded Thales and became the
second master of that school where he counted Anaximenes and arguably, Pythagoras amongst his pupils.
Little of his life and work is known today. According to available historical documents, he is the first philosopher
known to have written down his studies,[2] although only one fragment of his work remains. Fragmentary
testimonies found in documents after his death provide a portrait of the man.
Anaximander was one of the earliest Greek thinkers at the start of the Axial Age, the period from approximately
700 BC to 200 BC, during which similarly revolutionary thinking appeared in China, India, Iran, the Near East,
and Ancient Greece. He was an early proponent ofscience and tried to observe and explain different aspects of
the universe, with a particular interest in its origins, claiming that nature is ruled by laws, just like human
societies, and anything that disturbs the balance of nature does not last long. [3] Like many thinkers of his time,
Anaximander's contributions to philosophy relate to many disciplines. In astronomy, he tried to describe the
mechanics of celestial bodies in relation to the Earth. In physics, his postulation that the indefinite (or apeiron)
was the source of all things led Greek philosophy to a new level of conceptual abstraction. His knowledge
of geometry allowed him to introduce the gnomon in Greece. He created a map of the world that contributed
greatly to the advancement of geography. He was also involved in the politics of Miletus and was sent as a
leader to one of its colonies.
Anaximander claimed that an 'indefinite' (apeiron) principle gives rise to all natural phenomena. Carl Sagan
claims that he conducted the earliest recorded scientific experiment.[4]
Contents
[hide]
1 Biography
2 Theories

3. o 2.1 Apeiron
o 2.2 Cosmology
o 2.3 Multiple worlds
o 2.4 Meteorological phenomena
o 2.5 Origin of humankind
3 Other accomplishments
o 3.1 Cartography
o 3.2 Gnomon
o 3.3 Prediction of an earthquake
4 Interpretations
5 Works
6 See also
7 Footnotes
8 References
o 8.1 Primary sources
o 8.2 Secondary sources
9 External links
[edit] Biography
Anaximander, son of Praxiades, was born in Miletus during the third year of the 42nd Olympiad (610
BC).[5] According to Apollodorus, Greek grammarian of the 2nd century BC, he was sixty-four years old during
the second year of the 58th Olympiad (547-546 BC), and died shortly afterwards.[6]
Establishing a timeline of his work is now impossible, since no document provides chronological
references. Themistius, a 4th century Byzantine rhethorician, mentions that he was the "first of the known
Greeks to publish a written document on nature." Therefore his texts would be amongst the earliest written
in prose, at least in the Western world. By the time of Plato, his philosophy was almost forgotten, and Aristotle,
his successor Theophrastus and a few doxographers provide us with the little information that remains.
However, we know from Aristotle that Thales, also from Miletus, precedes Anaximander. It is debatable
whether Thales actually was the teacher of Anaximander, but there is no doubt that Anaximander was
influenced by Thales' theory that everything is derived from water. One thing that is not debatable is that even
the ancient Greeks considered Anaximander to be from the Monist school which began in Miletus with Thales
followed by Anaximander and finished with Anaximenes.[7] 3rd century Roman rhetorician Aelian depicts him as
leader of the Milesian colony toApollonia on the Black Sea coast, and hence some have inferred that he was a
prominent citizen. Indeed, Various History (III, 17) explains that philosophers sometimes also dealt with political

4. matters. It is very likely that leaders of Miletus sent him there as a legislator to create a constitution or simply to
maintain the colony’s allegiance.
[edit] Theories
Anaximander's theories were influenced by the Greek mythical tradition, and by some ideas of Thales – the
father of philosophy – as well as by observations made by older civilizations in the East (especially by the
Babylonian astrologists).[8] All these were elaborated rationally. In his desire to find some universal principle, he
assumed like traditional religion the existence of a cosmic order and in elaborating his ideas on this he used the
old mythical language which ascribed divine control to various spheres of reality. This was a common practice
for the Greek philosophers in a society which saw gods everywhere, therefore they could fit their ideas into a
tolerably elastic system.[9]
Some scholars[10] saw a gap between the existing mythical and the new rational way of thought which is the
main characteristic of the archaic period (8th to 6th century BC) in the Greekcity states. Because of this, they
didn't hesitate to speak for a 'Greek miracle'. But if we follow carefully the course of Anaximander's ideas, we
will notice that there was not such an abrupt break as initially appears. The basic elements of nature
(water, air, fire, earth) which the first Greek philosophers believed that constituted the universe represent in fact
theprimordial forces of previous thought. Their collision produced what the mythical tradition had
called cosmic harmony. In the old cosmogonies – Hesiod (8th-7th century BC) andPherecydes (6th century
BC) – Zeus establishes his order in the world by destroying the powers which were threatening this harmony,
(the Titans). Anaximander claimed that the cosmic order is not monarchic but geometric and this causes the
equilibrium of the earth which is lying in the centre of the universe. This is the projection on nature of a new
political order and a new space organized around a centre which is the static point of the system in the society
as in nature.[11] In this space there is isonomy (equal rights) and all the forces are symmetrical and
transferrable. The decisions are now taken by the assembly of demos in the agora which is lying in the middle
of the city.[12]
The same rational way of thought led him to introduce the abstract apeiron (indefinite, infinite, boundless,
unlimited[13]) as an origin of the universe, a concept that is probably influenced by the original Chaos (gaping
void, abyss, formless state) of the mythical Greek cosmogony from which everything else appeared.[14] It also
takes notice of the mutual changes between the four elements. Origin, then, must be something else unlimited
in its source, that could create without experiencing decay, so that genesis would never stop. [15]
[edit]Apeiron
Main article: Apeiron (cosmology)
The bishop Hippolytus of Rome (I, 5), and the later 6th century Byzantine philosopher Simplicius of Cilicia,
attribute to Anaximander the earliest use of the word apeíron (ἄπειπον infiniteor limitless) to designate the

5. original principle. He was the first philosopher to employ, in a philosophical context, the term arkhế (ἀπχή),
which until then had meant beginning or origin. For him, it became no longer a mere point in time, but a source
that could perpetually give birth to whatever will be. The indefiniteness is spatial in early usages as
in Homer (indefinite sea) and as in Xenophanes (6th century BC) who said that the earth went down indefinitely
(to apeiron) i.e. beyond the imagination or concept of men.[16]
Aristotle writes (Metaphysics, I III 3-4) that the Pre-Socratics were searching for the element that constitutes all
things. While each pre-Socratic philosopher gave a different answer as to the identity of this element (water for
Thales and air for Anaximenes), Anaximander understood the beginning or first principle to be an endless,
unlimited primordial mass (apeiron), subject to neither old age nor decay, that perpetually yielded fresh
materials from which everything we perceive is derived.[17] He proposed the theory of the apeiron in direct
response to the earlier theory of his teacher, Thales, who had claimed that the primary substance was water.
The notion of temporal infinity was familiar to the Greek mind from remote antiquity in the religious concept of
immortality and Anaximander's description was in terms appropriate to this conception. This arche is called
"eternal and ageless". (Hippolitus I,6,I;DK B2)[18]
For Anaximander, the principle of things, the constituent of all substances, is nothing determined and not an
element such as water in Thales' view. Neither is it something halfway between air and water, or between air
and fire, thicker than air and fire, or more subtle than water and earth.[19] Anaximander argues that water cannot
embrace all of the opposites found in nature — for example, water can only be wet, never dry — and therefore
cannot be the one primary substance; nor could any of the other candidates. He postulated the apeiron as a
substance that, although not directly perceptible to us, could explain the opposites he saw around him.
Anaximander explains how the four elements of ancient physics (air, earth, water and fire) are formed, and how
Earth and terrestrial beings are formed through their interactions. Unlike other Pre-Socratics, he never defines
this principle precisely, and it has generally been understood (e.g., by Aristotle and by Saint Augustine) as a
sort of primal chaos. According to him, the Universe originates in the separation of opposites in the primordial
matter. It embraces the opposites of hot and cold, wet and dry, and directs the movement of things; an entire
host of shapes and differences then grow that are found in "all the worlds" (for he believed there were many).
Anaximander maintains that all dying things are returning to the element from which they came (apeiron). The
one surviving fragment of Anaximander's writing deals with this matter. Simplicius transmitted it as a quotation,
which describes the balanced and mutual changes of the elements:[20]
Whence things have their origin,
Thence also their destruction happens,
According to necessity;
For they give to each other justice and recompense

6. For their injustice
In conformity with the ordinance of Time.
Simplicius mentions that Anaximander said all these "in poetic terms", meaning that he used the old mythical
language. The goddess Justice (Dike) keeps the cosmic order. This concept of returning to the element of
origin was often revisited afterwards, notably by Aristotle,[21] and by the Greek tragedian Euripides: "what
comes from earth must return to earth."[22] Friedrich Nietzsche, in his Philosophy in the Tragic Age of the
Greeks, stated that Anaximander viewed "...all coming-to-be as though it were an illegitimate emancipation
from eternal being, a wrong for which destruction is the only penance."[23]
[edit]Cosmology
Map of Anaximander's universe
Anaximander's bold use of non-mythological explanatory hypotheses considerably distinguishes him from
previous cosmology writers such as Hesiod. It confirms that pre-Socratic philosophers were making an early
effort to demythify physical processes. His major contribution to history was writing the oldest prose document
about the Universe and the origins of life; for this he is often called the "Father of Cosmology" and founder of
astronomy. However, pseudo-Plutarch states that he still viewed celestial bodies as deities.[24]
Anaximander was the first to conceive a mechanical model of the world. In his model, the Earth floats very still
in the centre of the infinite, not supported by anything. It remains "in the same place because of its
indifference", a point of view that Aristotle considered ingenious, but false, in On the Heavens.[25] Its curious
shape is that of a cylinder[26] with a height one-third of its diameter. The flat top forms the inhabited world, which
is surrounded by a circular oceanic mass.

7. Such a model allowed the concept that celestial bodies could pass under it. It goes further than Thales’ claim of
a world floating on water, for which Thales faced the problem of explaining what would contain this ocean,
while Anaximander solved it by introducing his concept of infinite (apeiron).
Illustration of Anaximander's models of the universe. On the left, daytime in summer; on the right, nighttime in winter.
At the origin, after the separation of hot and cold, a ball of flame appeared that surrounded Earth like bark on a
tree. This ball broke apart to form the rest of the Universe. It resembled a system of hollow concentric wheels,
filled with fire, with the rims pierced by holes like those of a flute. Consequently, the Sun was the fire that one
could see through a hole the same size as the Earth on the farthest wheel, and an eclipse corresponded with
theocclusion of that hole. The diameter of the solar wheel was twenty-seven times that of the Earth (or twenty-
eight, depending on the sources)[27] and the lunar wheel, whose fire was less intense, eighteen (or nineteen)
times. Its hole could change shape, thus explaining lunar phases. The stars and the planets, located
closer,[28] followed the same model.[29]
Anaximander was the first astronomer to consider the Sun as a huge mass, and consequently, to realize how
far from Earth it might be, and the first to present a system where the celestial bodies turned at different
distances. Furthermore, according to Diogenes Laertius (II, 2), he built a celestial sphere. This invention
undoubtedly made him the first to realize the obliquity of the Zodiac as the Roman philosopher Pliny the
Elder reports in Natural History (II, 8). It is a little early to use the term ecliptic, but his knowledge and work on
astronomy confirm that he must have observed the inclination of the celestial sphere in relation to the plane of
the Earth to explain the seasons. The doxographer and theologian Aetius attributes to Pythagoras the exact
measurement of the obliquity.
[edit]Multiple worlds

8. According to Simplicius, Anaximander already speculated on the plurality of worlds, similar
to atomists Leucippus and Democritus, and later philosopher Epicurus. These thinkers supposed that worlds
appeared and disappeared for a while, and that some were born when others perished. They claimed that this
movement was eternal, "for without movement, there can be no generation, no destruction". [30]
In addition to Simplicius, Hippolytus[31] reports Anaximander's claim that from the infinite comes the principle of
beings, which themselves come from the heavens and the worlds (several doxographers use the plural when
this philosopher is referring to the worlds within,[32] which are often infinite in quantity). Cicero writes that he
attributes different gods to the countless worlds.[33]
This theory places Anaximander close to the Atomists and the Epicureans who, more than a century later, also
claimed that an infinity of worlds appeared and disappeared. In thetimeline of the Greek history of thought,
some thinkers conceptualized a single world (Plato, Aristotle, Anaxagoras and Archelaus), while others instead
speculated on the existence of a series of worlds, continuous or non-continuous (Anaximenes,
Heraclitus, Empedocles and Diogenes).
[edit]Meteorological phenomena
Anaximander attributed some phenomena, such as thunder and lightning, to the intervention of elements,
rather than to divine causes.[34] In his system, thunder results from the shock of clouds hitting each other; the
loudness of the sound is proportionate with that of the shock. Thunder without lightning is the result of the wind
being too weak to emit any flame, but strong enough to produce a sound. A flash of lightning without thunder is
a jolt of the air that disperses and falls, allowing a less active fire to break free. Thunderbolts are the result of a
thicker and more violent air flow.[35]
He saw the sea as a remnant of the mass of humidity that once surrounded Earth.[36] A part of that mass
evaporated under the sun's action, thus causing the winds and even the rotation of the celestial bodies, which
he believed were attracted to places where water is more abundant.[37] He explained rain as a product of the
humidity pumped up from Earth by the sun.[5]For him, the Earth was slowly drying up and water only remained
in the deepest regions, which someday would go dry as well. According to Aristotle's Meteorology (II, 3),
Democritus also shared this opinion.
[edit]Origin of humankind
Anaximander speculated about the beginnings and origin of animal life. Taking into account the existence of
fossils, he claimed that animals sprang out of the sea long ago. The first animals were born trapped in a spiny
bark, but as they got older, the bark would dry up and break.[38] As the early humidity evaporated, dry land
emerged and, in time, humankind had to adapt. The 3rd century Roman writer Censorinus reports:

9. Anaximander of Miletus considered that from warmed up water and earth emerged either fish or entirely fishlike
animals. Inside these animals, men took form and embryos were held prisoners until puberty; only then, after
these animals burst open, could men and women come out, now able to feed themselves.[39]
Anaximander put forward the idea that humans had to spend part of this transition inside the mouths of big fish
to protect themselves from the Earth's climate until they could come out in open air and lose their scales. [40] He
thought that, considering humans' extended infancy, we could not have survived in the primeval world in the
same manner we do presently.
Even though he had no theory of natural selection, some people consider him as evolution's most ancient
proponent. The theory of an aquatic descent of man was re-conceived centuries later as the aquatic ape
hypothesis. These pre-Darwinian concepts may seem strange, considering modern knowledge and scientific
methods, because they present complete explanations of the universe while using bold and hard-to-
demonstrate hypotheses. However, they illustrate the beginning of a phenomenon sometimes called the
"Greek miracle": men try to explain the nature of the world, not with the aid of myths or religion, but with
material principles. This is the very principle of scientific thought, which was later advanced further by improved
research methods.
[edit] Other accomplishments
[edit]Cartography
Possible rendering of Anaximander's world map[41]
Both Strabo and Agathemerus (later Greek geographers) claim that, according to the
geographer Eratosthenes, Anaximander was the first to publish a map of the world. The map probably inspired

10. the Greek historian Hecataeus of Miletus to draw a more accurate version. Strabo viewed both as the first
geographers after Homer.
Maps were produced in ancient times, also notably in Egypt, Lydia, the Middle East, and Babylon. Only some
small examples survived until today. The unique example of a world map comes from late Babylonian tablet
BM 92687 later than 9th century BCE but is based probably on a much older map. These maps indicated
directions, roads, towns, borders, and geological features. Anaximander's innovation was to represent the
entire inhabited land known to the ancient Greeks.
Such an accomplishment is more significant than it at first appears. Anaximander most likely drew this map for
three reasons.[42]First, it could be used to improve navigation and trade between Miletus's colonies and other
colonies around the Mediterranean Sea and Black Sea. Second, Thales would probably have found it easier to
convince the Ionian city-states to join in a federation in order to push the Median threat away if he possessed
such a tool. Finally, the philosophical idea of a global representation of the world simply for the sake of
knowledge was reason enough to design one.
Surely aware of the sea's convexity, he may have designed his map on a slightly rounded metal surface. The
centre or ―navel‖ of the world (ὀμφαλόρ γῆρ omphalós gẽs) could have been Delphi, but is more likely in
Anaximander's time to have been located near Miletus. The Aegean Sea was near the map's centre and
enclosed by three continents, themselves located in the middle of the ocean and isolated like islands by sea
and rivers. Europe was bordered on the south by the Mediterranean Sea and was separated from Asia by the
Black Sea, the Lake Maeotis, and, further east, either by the Phasis River (now called the Rioni) or the Tanais.
TheNile flowed south into the ocean, separating Libya (which was the name for the part of the then-
known African continent) from Asia.
[edit]Gnomon
The Suda relates that Anaximander explained some basic notions of geometry. It also mentions his interest in
the measurement of time and associates him with the introduction inGreece of the gnomon. In Lacedaemon, he
participated in the construction, or at least in the adjustment, of sundials to
indicate solstices and equinoxes.[43] Indeed, a gnomon required adjustments from a place to another because
of the difference in latitude.
In his time, the gnomon was simply a vertical pillar or rod mounted on a horizontal plane. The position of its
shadow on the plane indicated the time of day. As it moves through its apparent course, the sun draws a curve
with the tip of the projected shadow, which is shortest at noon, when pointing due south. The variation in the
tip’s position at noon indicates the solar time and the seasons; the shadow is longest on the winter solstice and
shortest on the summer solstice.

11. However, the invention of the gnomon itself cannot be attributed to Anaximander because its use, as well as
the division of days into twelve parts, came from the Babylonians. It is they, according
to Herodotus' Histories (II, 109), who gave the Greeks the art of time measurement. It is likely that he was not
the first to determine the solstices, because no calculation is necessary. On the other hand, equinoxes do not
correspond to the middle point between the positions during solstices, as the Babylonians thought. As
the Suda seems to suggest, it is very likely that with his knowledge of geometry, he became the first Greek to
accurately determine the equinoxes.
[edit]Prediction of an earthquake
In his philosophical work De Divinatione (I, 50, 112), Cicero states that Anaximander convinced the inhabitants
of Lacedaemon to abandon their city and spend the night in the country with their weapons because an
earthquake was near.[44] The city collapsed when the top of the Taygetus split like the stern of a ship. Pliny the
Elder also mentions this anecdote (II, 81), suggesting that it came from an "admirable inspiration", as opposed
to Cicero, who did not associate the prediction with divination.
[edit] Interpretations
Bertrand Russell in the History of Western Philosophy interprets Anaximander's theories as an assertion of the
necessity of an appropriate balance between earth, fire, and water, all of which may be independently seeking
to aggrandize their proportions relative to the others. Anaximander seems to express his belief that a natural
order ensures balance between these elements, that where there was fire, ashes (earth) now exist.[45] His
Greek peers echoed this sentiment with their belief in natural boundaries beyond which not even their gods
could operate.
Friedrich Nietzsche, in Philosophy in the Tragic Age of the Greeks, claimed that Anaximander was a pessimist
who asserted that the primal being of the world was a state of indefiniteness. In accordance with this, anything
definite has to eventually pass back into indefiniteness. In other words, Anaximander viewed "...all coming-to-
be as though it were an illegitimate emancipation from eternal being, a wrong for which destruction is the only
penance". (Ibid., § 4) The world of individual objects, in this way of thinking, has no worth and should perish. [46]
Martin Heidegger lectured extensively on Anaximander, and delivered a lecture entitled "Anaximander's
Saying" which was subsequently included in Off the Beaten Track. The lecture examines the ontological
difference and the oblivion of Being or Dasein in the context of the Anaximander fragment.[47] Heidegger's
lecture is, in turn, an important influence on the French philosopher Jacques Derrida.[48]
Anaximander (c.610—546 BCE)

12. Anaximander was the author of the first surviving lines of Western philosophy. He
speculated and argued about “the Boundless” as the origin of all that is. He also worked on the fields
of what we now call geography and biology. Moreover, Anaximander was the first speculative
astronomer. He originated the world-picture of the open universe, which replaced the closed
universe of the celestial vault.
Table of Contents
1. Life and Sources
2. The “Boundless” as Principle
3. The Arguments Regarding the Boundless
a. The Boundless has No Origin
b. The Origin must be Boundless
c. The “Long Since” Argument
The Fragment
The Origin of the Cosmos
Astronomy
. Speculative Astronomy
a. The Celestial Bodies Make Full Circles
b. The Earth Floats Unsupported in Space
c. Why the Earth Does Not Fall
d. The Celestial Bodies Lie Behind One Another
e. The Order of the Celestial Bodies
f. The Celestial Bodies as Wheels
g. The Distances of the Celestial Bodies
h. A Representation of Anaximander’s Universe
Map of the World
Biology
Conclusion
References and Further Reading
1. Life and Sources
The history of written Greek philosophy starts with Anaximander of Miletus in Asia Minor, a fellow-
citizen of Thales. He was the first who dared to write a treatise in prose, which has been called
traditionally On Nature. This book has been lost, although it probably was available in the library of
the Lyceum at the times of Aristotle and his successor Theophrastus. It is said that Apollodorus, in the
second century BCE, stumbled upon a copy of it, perhaps in the famous library of Alexandria.
Recently, evidence has appeared that it was part of the collection of the library of Taormina in Sicily,
where a fragment of a catalogue has been found, on which Anaximander‟s name can be read. Only

13. one fragment of the book has come down to us, quoted by Simplicius (after Theophrastus), in the
sixth century AD. It is perhaps the most famous and most discussed phrase in the history of
philosophy.
We also know very little of Anaximander‟s life. He is said to have led a mission that founded a colony
called Apollonia on the coast of the Black Sea. He also probably introduced the gnomon (a
perpendicular sun-dial) into Greece and erected one in Sparta. So he seems to have been a much-
traveled man, which is not astonishing, as the Milesians were known to be audacious sailors. It is
also reported that he displayed solemn manners and wore pompous garments. Most of the
information on Anaximander comes fromAristotle and his pupil Theophrastus, whose book on the
history of philosophy was used, excerpted, and quoted by many other authors, the so-called
doxographers, before it was lost. Sometimes, in these texts words or expressions appear that can with
some certainty be ascribed to Anaximander himself. Relatively many testimonies, approximately one
third of them, have to do with astronomical and cosmological questions. Hermann Diels and Walter
Kranz have edited the doxography (A) and the existing texts (B) of the Presocratic philosophers in
Die Fragmente der Vorsokratiker, Berlin 1951-19526. (A quotation like “DK 12A17″ means:
“Diels/Kranz, Anaximander, doxographical report no.17″).
2. The ―Boundless‖ as Principle
According to Aristotle and Theophrastus, the first Greek philosophers were looking for the “origin” or
“principle” (the Greek word “archê” has both meanings) of all things. Anaximander is said to have
identified it with “the Boundless” or “the Unlimited” (Greek: “apeiron,” that is, “that which has no
boundaries”). Already in ancient times, it is complained that Anaximander did not explain what he
meant by “the Boundless.” More recently, authors have disputed whether the Boundless should be
interpreted as spatially or temporarily without limits, or perhaps as that which has no qualifications,
or as that which is inexhaustible. Some scholars have even defended the meaning “that which is not
experienced,” by relating the Greek word “apeiron” not to “peras” (“boundary,” “limit”), but to
“perao” (“to experience,” “to apperceive”). The suggestion, however, is almost irresistible that Greek
philosophy, by making the Boundless into the principle of all things, has started on a high level of
abstraction. On the other hand, some have pointed out that this use of “apeiron” is atypical for Greek
thought, which was occupied with limit, symmetry and harmony. The Pythagoreans placed the
boundless (the “apeiron”) on the list of negative things, and for Aristotle, too, perfection became
aligned with limit (Greek: “peras”), and thus “apeiron” with imperfection. Therefore, some authors
suspect eastern (Iranian) influence on Anaximander‟s ideas.
3. The Arguments Regarding the Boundless
It seems that Anaximander not only put forward the thesis that the Boundless is the principle, but
also tried to argue for it. We might say that he was the first who made use of philosophical
arguments. Anaximander‟s arguments have come down to us in the disguise of Aristotelian jargon.
Therefore, any reconstruction of the arguments used by the Milesian must remain
conjectural. Verbatim reconstruction is of course impossible. Nevertheless, the data, provided they
are handled with care, allow us to catch glimpses of what the arguments of Anaximander must have

14. looked like. The important thing is, however, that he did not just utter apodictic statements, but also
tried to give arguments. This is what makes him the first philosopher.
a. The Boundless has No Origin
Aristotle reports a curious argument, which probably goes back to Anaximander, in which it is argued
that the Boundless has no origin, because it is itself the origin. We would say that it looks more like a
string of associations and word-plays than like a formal argument. It runs as follows: “Everything has
an origin or is an origin. The Boundless has no origin. For then it would have a limit. Moreover, it is
both unborn and immortal, being a kind of origin. For that which has become has also, necessarily,
an end, and there is a termination to every process of destruction” (Physics 203b6-10, DK 12A15).
The Greeks were familiar with the idea of the immortal Homeric gods. Anaximander added two
distinctive features to the concept of divinity: his Boundless is an impersonal something (or “nature,”
the Greek word is “phusis”), and it is not only immortal but also unborn. However, perhaps not
Anaximander, but Thales should be credited with this new idea. Diogenes Laërtius ascribes
to Thales the aphorism: “What is the divine? That which has no origin and no end” (DK 11A1 (36)).
Similar arguments, within different contexts, are used by Melissus (DK 30B2[9]) and Plato
(Phaedrus 245d1-6).
b. The Origin Must be Boundless
Several sources give another argument which is somehow the other way round and answers the
question of why the origin should be boundless. In Aristotle’s version, it runs like this: “(The belief
that there is something Boundless stems from) the idea that only then genesis and decay will never
stop, when that from which is taken what has been generated, is boundless” (Physics 203b18-20, DK
12A15, other versions in DK12A14 and 12A17). In this argument, the Boundless seems to be
associated with an inexhaustible source. Obviously, it is taken for granted that “genesis and decay
will never stop,” and the Boundless has to guarantee the ongoing of the process, like an ever-floating
fountain.
c. The ―Long Since‖ Argument
A third argument is relatively long and somewhat strange. It turns on one key word (in Greek: “êdê”),
which is here translated with “long since.” It is reproduced by Aristotle: “Some make this (namely,
that which is additional to the elements) the Boundless, but not air or water, lest the others should be
destroyed by one of them, being boundless; for they are opposite to one another (the air, for instance,
is cold, the water wet, and the fire hot). If any of them should be boundless, it would long since have
destroyed the others; but now there is, they say, something other from which they are all generated”
(Physics 204b25-29, DK 12A16).
This is not only virtually the same argument as used by Plato in his Phaedo (72a12-b5), but even
more interesting is that it was used almost 2500 years later by Friedrich Nietzsche in his attempts to
prove his thesis of the Eternal Recurrence: “If the world had a goal, it would have been reached. If
there were for it some unintended final state, this also must have been reached. If it were at all

15. capable of a pausing and becoming fixed, if it were capable of “being,” if in the whole course of its
becoming it possessed even for a moment this capability of “being,” then again all becoming
would long since have come to an end.” Nietzsche wrote these words in his notebook in 1885, but
already in Die Philosophie im tragischen Zeitalter der Griechen (1873), which was not published
during his lifetime, he mentioned the argument and credited Anaximander with it.
4. The Fragment
The only existing fragment of Anaximander‟s book (DK 12B1) is surrounded by all kinds of questions.
The ancient Greeks did not use quotation marks, so that we cannot be sure where Simplicius, who
has handed down the text to us, is still paraphrasing Anaximander and where he begins to quote
him. The text is cast in indirect speech, even the part which most authors agree is a real quotation.
One important word of the text (“allêlois,” here translated by “upon one another”) is missing in some
manuscripts. As regards the interpretation of the fragment, it is heavily disputed whether it means to
refer to Anaximander‟s principle, the Boundless, or not. The Greek original has relative pronouns in
the plural (here rendered by “whence” and “thence”), which makes it difficult to relate them to the
Boundless. However, Simplicius‟ impression that it is written in rather poetic words has been
repeated in several ways by many authors. Therefore, we offer a translation, in which some poetic
features of the original, such as chiasmus and alliteration have been imitated:
Whence things have their origin,
Thence also their destruction happens,
As is the order of things;
For they execute the sentence upon one another
- The condemnation for the crime -
In conformity with the ordinance of Time.
In the fourth and fifth line a more fluent translation is given for what is usually rendered rather
cryptic by something like “giving justice and reparation to one another for their injustice.”
We may distinguish roughly two lines of interpretation, which may be labeled the “horizontal” and
the “vertical.” The horizontal interpretation holds that in the fragment nothing is said about the
relation of the things to the Boundless, whereas the vertical interpretation maintains that the
fragment describes the relationship of the things to the Boundless. The upholders of the horizontal
interpretation usually do not deny that Anaximander taught that all things are generated from the
Boundless, but they simply hold that this is not what is said in the fragment. They argue that the
fragment describes the battle between the elements (or of things in general), which accounts for the
origin and destruction of things. The most obvious difficulty, however, for this “horizontal”
interpretation is that it implies two cycles of becoming and decay: one from and into the Boundless,
and the other caused by the mutual give and take of the elements or things in general. In other
words, in the “horizontal” interpretation the Boundless is superfluous. This is the strongest
argument in favor of the “vertical” interpretation, which holds that the fragment refers to the
Boundless, notwithstanding the plural relative pronouns. According to the “vertical” interpretation,
then, the Boundless should be regarded not only as the ever-flowing fountain from which everything
ultimately springs, but also as the yawning abyss (as some say, comparable with Hesiod‟s “Chaos”)
into which everything ultimately perishes.

16. The suggestion has been raised that Anaximander‟s formula in the first two lines of the fragment
should have been the model for Aristotle’s definition of the “principle” (Greek: “archê”) of all things
inMetaphysics 983b8. There is some sense in this suggestion. For what could be more natural
for Aristotlethan to borrow his definition of the notion of “archê,” which he uses to indicate the
principle of the first presocratic philosophers, from Anaximander, the one who introduced the
notion?
It is certainly important that we possess one text from Anaximander‟s book. On the other hand, we
must recognize that we know hardly anything of its original context, as the rest of the book has been
lost. We do not know from which part of his book it is, nor whether it is a text the author himself
thought crucial or just a line that caught one reader‟s attention as an example of Anaximander‟s
poetic writing style. The danger exists that we are tempted to use this stray text – beautiful and
mysterious as it is – in order to produce all kinds of profound interpretations that are hard to verify.
Perhaps a better way of understanding what Anaximander has to say is to study carefully the
doxography, which goes back to people like Aristotle and Theophrastus, who probably have had
Anaximander‟s book before their eyes, and who tried to reformulate what they thought were its
central claims.
5. The Origin of the Cosmos
The Boundless seems to have played a role in Anaximander‟s account of the origin of the cosmos. Its
eternal movement is said to have caused the origin of the heavens. Elsewhere, it is said that “all the
heavens and the worlds within them” have sprung from “some boundless nature.” A part of this
process is described in rather poetic language, full of images, which seems to be idiosyncratic for
Anaximander: “a germ, pregnant with hot and cold, was separated [or: separated itself] off from the
eternal, whereupon out of this germ a sphere of fire grew around the vapor that surrounds the earth,
like a bark round a tree” (DK 12A10). Subsequently, the sphere of fire is said to have fallen apart into
several rings, and this event was the origin of sun, moon, and stars. There are authors who have,
quite anachronistically, seen here a kind of foreshadowing of the Kant-Laplace theory of the origin of
the solar system. Some sources even mention innumerable worlds (in time and/or in space), which
looks like a plausible consequence of the Boundless as principle. But this is presumably a later
theory, incorrectly read back into Anaximander.
6. Astronomy
At first sight, the reports on Anaximander‟s astronomy look rather bizarre and obscure. Some
authors even think that they are so confused that we should give up trying to offer a satisfying and
coherent interpretation. The only way of understanding Anaximander‟s astronomical ideas, however,
is to take them seriously and treat them as such, that is, as astronomical ideas. It will appear that
many of the features of his universe that look strange at first sight make perfect sense on closer
inspection.
a. Speculative Astronomy

17. The astronomy of neighboring peoples, such as the Babylonians and the Egyptians, consists mainly
of observations of the rising and disappearance of celestial bodies and of their paths across the
celestial vault. These observations were made with the naked eye and with the help of some simple
instruments as the gnomon. The Babylonians, in particular, were rather advanced observers.
Archeologists have found an abundance of cuneiform texts on astronomical observations. In
contrast, there exists only one report of an observation made by Anaximander, which concerns the
date on which the Pleiades set in the morning. This is no coincidence, for Anaximander‟s merits do
not lie in the field of observational astronomy, unlike the Babylonians and the Egyptians, but in that
of speculative astronomy. We may discern three of his astronomical speculations: (1) that the
celestial bodies make full circles and pass also beneath the earth, (2) that the earth floats free and
unsupported in space, and (3) that the celestial bodies lie behind one another. Notwithstanding their
rather primitive outlook, these three propositions, which make up the core of Anaximander‟s
astronomy, meant a tremendous jump forward and constitute the origin of our Western concept of
the universe.
b. The Celestial Bodies Make Full Circles
The idea that the celestial bodies, in their daily course, make full circles and thus pass also beneath
the earth – from Anaximander‟s viewpoint – is so self-evident to us that it is hard to understand how
daring its introduction was. That the celestial bodies make full circles is not something he could
have observed,but a conclusion he must have drawn. We would say that this is a conclusion that lies
to hand. We can see – at the northern hemisphere, like Anaximander – the stars around the Polar
star making full circles, and we can also observe that the more southerly stars sometimes disappear
behind the horizon. We may argue that the stars of which we see only arcs in reality also describe full
circles, just like those near the Polar star. As regards the sun and moon, we can observe that the arcs
they describe are sometimes bigger and sometimes smaller, and we are able to predict exactly where
they will rise the next day. Therefore, it seems not too bold a conjecture to say that these celestial
bodies also describe full circles. Nevertheless, it was a daring conclusion, precisely because it
necessarily entailed the concept of the earth hanging free and unsupported in space.
c. The Earth Floats Unsupported in Space
Anaximander boldly asserts that the earth floats free in the center of the universe, unsupported by
water, pillars, or whatever. This idea means a complete revolution in our understanding of the
universe. Obviously, the earth hanging free in space is not something Anaximander could
have observed.Apparently, he drew this bold conclusion from his assumption that the celestial
bodies make full circles. More than 2500 years later astronauts really saw the unsupported earth
floating in space and thus provided the ultimate confirmation of Anaximander‟s conception. The
shape of the earth, according to Anaximander, is cylindrical, like a column-drum, its diameter being
three times its height. We live on top of it. Some scholars have wondered why Anaximander chose
this strange shape. The strangeness disappears, however, when we realize that Anaximander thought
that the earth was flat and circular, as suggested by the horizon. For one who thinks, as Anaximander
did, that the earth floats unsupported in the center of the universe, the cylinder-shape lies at hand.

18. d. Why the Earth Does Not Fall
We may assume that Anaximander somehow had to defend his bold theory of the free-floating,
unsupported earth against the obvious question of why the earth does not fall. Aristotle’s version of
Anaximander‟s argument runs like this: “But there are some who say that it (namely, the earth) stays
where it is because of equality, such as among the ancients Anaximander. For that which is situated
in the center and at equal distances from the extremes, has no inclination whatsoever to move up
rather than down or sideways; and since it is impossible to move in opposite directions at the same
time, it necessarily stays where it is.” (De caelo 295b10ff., DK 12A26) Many authors have pointed to
the fact that this is the first known example of an argument that is based on the principle of sufficient
reason (the principle that for everything which occurs there is a reason or explanation for why it
occurs, and why this way rather than that).
Anaximander‟s argument returns in a famous text in the Phaedo (108E4 ff.), where Plato, for the first
time in history, tries to express the sphericity of the earth. Even more interesting is that the same
argument, within a different context, returns with the great protagonist of the principle of sufficient
reason, Leibniz. In his second letter to Clarke, he uses an example, which he ascribes to Archimedes
but which reminds us strongly of Anaximander: “And therefore Archimedes (…) in his book De
aequilibrio,was obliged to make use of a particular case of the great Principle of a sufficient reason.
He takes it for granted that if there be a balance in which everything is alike on both sides, and if
equal weights are hung on the two ends of that balance, the whole will stay at rest. This is because
there is no reason why one side should weigh down, rather than the other”.
One may doubt, however, whether the argument is not fallacious. Aristotle already thought the
argument to be deceiving. He ridicules it by saying that according to the same kind of argument a
hair, which was subject to an even pulling power from opposing sides, would not break, and that a
man, being just as hungry as thirsty, placed in between food and drink, must necessarily remain
where he is and starve. To him it was the wrong argument for the right proposition. Absolute
propositions concerning the non-existence of things are always in danger of becoming falsified on
closer investigation. They contain a kind of subjective aspect: “as far as I know.” Several authors,
however, have said that Anaximander‟s argument is clear and ingenious. Already at first sight this
qualification sounds strange, for the argument evidently must be wrong, as the earth is not in the
center of the universe, although it certainly is not supported by anything but gravity. Nevertheless,
we have to wait until Newton for a better answer to the question why the earth does not fall.
e. The Celestial Bodies Lie Behind One Another
When Anaximander looked at the heaven, he imagined, for the first time in
history, space. Anaximander‟s vision implied depth in the universe, that is, the idea that the celestial
bodies lie behind one another. Although it sounds simple, this is a remarkable idea, because it cannot
be based on direct observation. We do not see depth in the universe. The more natural and primitive
idea is that of the celestial vault, a kind of dome or tent, onto which the celestial bodies are attached,
all of them at the same distance, like in a planetarium. One meets this kind of conception in Homer,
when he speaks of the brazen or iron heaven, which is apparently conceived of as something solid,
being supported by Atlas, or by pillars.

19. f. The Order of the Celestial Bodies
Anaximander placed the celestial bodies in the wrong order. He thought that the stars were nearest
to the earth, then followed the moon, and the sun farthest away. Some authors have wondered why
Anaximander made the stars the nearest celestial bodies, for he should have noticed the occurrence
of star-occultations by the moon. This is a typical anachronism, which shows that it not easy to look
at the phenomena with Anaximander‟s eyes. Nowadays, we know that the stars are behind the moon,
and thus we speak of star-occultation when we see a star disappear behind the moon. But
Anaximander had no reason at all, from his point of view, to speak of a star-occultation when he saw
a star disappear when the moon was at the same place. So it is a petitio principii to say that for him
occultations of stars were easy to observe. Perhaps he observed stars disappearing and appearing
again, but he did not observe – could not see it as – the occultation of the star, for that interpretation
did not fit his paradigm. The easiest way to understand his way of looking at it – if he observed the
phenomenon at all – is that he must have thought that the brighter light of the moon outshines the
much smaller light of the star for a while. Anaximander‟s order of the celestial bodies is clearly that
of increasing brightness. Unfortunately, the sources do not give further information of his
considerations at this point.
g. The Celestial Bodies as Wheels
A peculiar feature of Anaximander‟s astronomy is that the celestial bodies are said to be like chariot
wheels (the Greek words for this image are presumably his own). The rims of these wheels are of
opaque vapor, they are hollow, and filled with fire. This fire shines through at openings in the wheels,
and this is what we see as the sun, the moon, or the stars. Sometimes, the opening of the sun wheel
closes: then we observe an eclipse. The opening of the moon wheel regularly closes and opens again,
which accounts for the phases of the moon. This image of the celestial bodies as huge wheels seems
strange at first sight, but there is a good reason for it. There is no doxographic evidence of it, but it is
quite certain that the question of why the celestial bodies do not fall upon the earth must have been
as serious a problem to Anaximander as the question of why the earth does not fall. The explanation
of the celestial bodies as wheels, then, provides an answer to both questions. The celestial bodies
have no reason whatsoever to move otherwise than in circles around the earth, as each point on them
is always as far from the earth as any other. It is because of reasons like this that for ages to come,
when Anaximander‟s concept of the universe had been replaced by a spherical one, the celestial
bodies were thought of as somehow attached to crystalline or ethereal sphere-shells, and not as free-
floating bodies.
Many authors, following Diels, make the image of the celestial wheels more difficult than is
necessary. They say that the light of a celestial bodies shines through the openings of its wheel “as
through the nozzle of a bellows.” This is an incorrect translation of an expression that probably goes
back to Anaximander himself. The image of a bellows, somehow connected to a celestial wheel, tends
to complicate rather than elucidate the meaning of the text. If we were to understand that every
celestial body had such a bellows, the result would be hundreds of nozzles (or pipes), extending from
the celestial wheels towards the earth. Anaximander‟s intention, however, can be better understood
not as an image, but as a comparison of the light of the celestial bodies with that of lightning.
Lightning, according to Anaximander, is a momentary flash of light against a dark cloud. The light of

20. a celestial body is like a permanent beam of lightning fire that originates from the opaque cloudy
substance of the celestial wheel.
h. The Distances of the Celestial Bodies
The doxography gives us some figures about the dimensions of Anaximander‟s universe: the sun
wheel is 27 or 28 times the earth, and the moon wheel is 19 times the earth. More than a century ago,
two great scholars, Paul Tannery and Hermann Diels, solved the problem of Anaximander‟s
numbers. They suggested that the celestial wheels were one unit thick, this unit being the diameter of
the earth. The full series, they argued, had to be: 9 and 10 for the stars, 18 and 19 for the moon, and
27 and 28 for the sun. These numbers are best understood as indicating the distances of the celestial
bodies to the earth. In others words, they indicate the radii of concentric circles, made by the celestial
wheels, with the earth as the center. See Figure 1, a plane view of Anaximander‟s universe.
These numbers cannot be based on observation. In order to understand their meaning, we have to
look at Hesiod‟s Theogony 722-725, where it is said that a brazen anvil would take nine days to fall
from heaven to earth before it arrives on the tenth day. It is not a bold guess to suppose that
Anaximander knew this text. The agreement with his numbers is too close to neglect, for the
numbers 9 and 10 are exactly those extrapolated for Anaximander‟s star wheel. Hesiod can be seen
as a forerunner to Anaximander, for he tried to imagine the distance to the heaven. In the Greek
counting system Hesiod‟s numbers should be taken to mean “a very long time.” Thus, Troy was

21. conquered in the tenth year after having stood the siege for nine years; and Odysseus scoured the
seas for nine years before reaching his homeland in the tenth year. We may infer that Anaximander,
with his number 9 (1 x 3 x 3) for the star ring, simply was trying to say that the stars are very far
away. Now the numbers 18 and 27 can easily be interpreted as “farther” (2 x 3 x 3, for the moon ring)
and “farthest” (3 x 3 x 3, for the sun ring). And this is exactly what we should expect one to say, who
had discovered that the image of the celestial vault was wrong but that the celestial bodies were
behind one another, and who wished to share this new knowledge with his fellow citizens in a
language they were able to understand.
i. A Representation of Anaximander’s Universe
Although it is not attested in the doxography, we may assume that Anaximander himself drew a map
of the universe, like that in figure 1. The numbers, 9, 10, 18, etc., can easily be understood as
instructions for making such a map. Although Diogenes Laërtius reports that he made a “sphere,” the
drawing or construction of a three-dimensional model must be considered to have been beyond
Anaximander‟s abilities. On the other hand, it is quite easy to explain the movements of the celestial
bodies with the help of a plan view, by making broad gestures, describing circles in the air, and
indicating direction, speed, and inclination with your hands, as is said of a quarrel
between Anaxagoras and Oenopides (DK 41A2).
Almost nothing of Anaximander‟s opinions about the stars has been handed down to us. Probably
the best way to imagine them is as a conglomerate of several wheels, each of which has one or more
holes, through which the inner fire shines, which we see as stars. The most likely sum-total of these
star wheels is a sphere. The only movement of these star wheels is a rotation around the earth from
east to west, always at the same speed, and always at the same place relative to one another in the
heaven. The sun wheel shows the same rotation from east to west as the stars, but there are two
differences. The first is that the speed of the rotation of the sun wheel is not the same as that of the
stars. We can see this phenomenon by observing how the sun lags behind by approximately one
degree per day. The second difference is that the sun wheel as a whole changes its position in the
heaven. In summer it moves towards the north along the axis of the heaven and we see a large part of
it above the horizon, whereas in winter we only observe a small part of the sun wheel, as it moves
towards the south. This movement of the sun wheel accounts for the seasons. The same
holds mutatis mutandis for the moon. Today, we use to describe this movement of the sun
(and mutatis mutandis of the moon and the planets) as a retrograde movement, from west to east,
which is a counter-movement to the daily rotation from east to west. In terms of Anaximander‟s
ancient astronomy it is more appropriate and less anachronistic to describe it as a slower movement
of the sun wheel from east to west. The result is that we see different stars in different seasons, until
the sun, at the end of a year, reaches its old position between the stars.
Due to the inclination of the axis of the heaven, the celestial bodies do not circle around the earth in
the same plane as the earth‟s – flat – surface, but are tilted. This inclination amounts to about 38.5
degrees when measured at Delphi, the world‟s navel. The earth being flat, the inclination must be the
same all over its surface. This tilting of the heaven‟s axis must have been one of the biggest riddles of
the universe. Why is it tilted at all? Who or what is responsible for this phenomenon? And why is it
tilted just the way it is? Unfortunately, the doxography on Anaximander has nothing to tell us about

22. this problem. Later, other Presocratics like Empedocles, Diogenes of Apollonia,
and Anaxagoras discuss the tilting of the heavens.
Although there exists a report that says the contrary, it is not likely that Anaximander was
acquainted with the obliquity of the ecliptic, which is the yearly path of the sun along the stars. The
ecliptic is a concept which belongs to the doctrine of a spherical earth within a spherical universe. A
three-dimensional representation of Anaximander‟s universe is given in Figures 2 and 3.
7. Map of the World
Anaximander is said to have made the first map of the world. Although this map has been lost, we
can imagine what it must have looked like, because Herodotus, who has seen such old maps,
describes them. Anaximander‟s map must have been circular, like the top of his drum-shaped earth.
The river Ocean surrounded it. The Mediterranean Sea was in the middle of the map, which was
divided into two halves by a line that ran through Delphi, the world‟s navel. The northern half was
called “Europe,” the southern half “Asia.” The habitable world (Greek: “oikoumenê”) consisted of two
relatively small strips of land to the north and south of the Mediterranean Sea (containing Spain,
Italy, Greece, and Asia Minor on the one side, and Egypt and Libya on the other side), together with
the lands to the east of the Mediterranean Sea: Palestine, Assyria, Persia, and Arabia. The lands to
the north of this small “habitable world” were the cold countries where mythical people lived. The
lands to the south of it were the hot countries of the black burnt people.

23. 8. Biology
The doxography tells us that according to Anaximander life originated from the moisture that
covered the earth before it was dried up by the sun. The first animals were a kind of fish, with a
thorny skin (the Greek word is the same that was used for the metaphor “the bark of a tree” in
Anaximander‟s cosmology). Originally, men were generated from fishes and were fed in the manner
of a viviparous shark. The reason for this is said to be that the human child needs long protection in
order to survive. Some authors have, rather anachronistically, seen in these scattered statements a
proto-evolutionist theory.
9. Conclusion
It is no use trying to unify the information on Anaximander into one all-compassing and consistent
whole. His work will always remain truncated, like the mutilated and decapitated statue that has
been found at the market-place of Miletus and that bears his name. Nevertheless, by what we know
of him, we may say that he was one of the greatest minds that ever lived. By speculating and arguing
about the “Boundless” he was the first metaphysician. By drawing a map of the world he was the first
geographer. But above all, by boldly speculating about the universe he broke with the ancient image
of the celestial vault and became the discoverer of the Western world-picture.
Anaximander
1. Introduction
2. Philosophical Views
2.1. The Apeiron
2.2. Harmony of the Opposites
2.3. The Apeiron as Unconditioned and God
1. Introduction
Anaximander was a younger contemporary of Thales, who also sought for the
first material principle; he was a disciple and successor of Thales and
philosophized in dialogue with him. Anaximander was not mentioned until the
time of Aristotle, who classifies him as belonging the "physical" school of
thought of Thales. Unlike Thales, Anaximander wrote a philosophical work,
entitled On Nature; unfortunately, neither this work nor any of his others has

24. survived. Information about his philosophy come from summaries of it by other
writers, especially Aristotle and Theophrastus. Anaximander was said to have
drawn the first map of the inhabited world on a tablet, which was a marvel in
his day (Agathemerus I, 1)
2. Philosophical Views
2.1. The Apeiron
Anaximander shares Thales' assumption that all things originate from one
original element and ultimately are that element; to use Aristotle's terminology,
he holds that there is a first (material) principle (archê) of all things. Unlike
Thales, however, Anaximander asserts that the first principle is not water, but
what he calls theapeiron, translated as the Indeterminate or
Limitless. Simplicius, drawing upon Theophrastus' work, gives the following
account of Anaximander's view:
Anaximander named the archê and element of existing things the apeiron, being the first to introduce this
name for the archê. He says that it is neither water nor any other of the so-called elements, but a different
substance that is limitless or indeterminate, from which there come into being all the heavens and the
worlds within them. Things perish into those things out of which they have their being, according to
necessity. (Phys. 24. 13)
For Anaximander, the archê, or first principle, is not any of the elements—
earth, water, air or fire—but that which precedes the elements (and everything
else), from which the elements emerge and which they all ultimately are (see
also Aristotle, Physics I.4; 187a 12: "something else which is denser than fire
and rarer than air then generate everything else from this, and obtain
multiplicity by condensation and rarefaction"). From it comes all things, but it is
none of those things: "all the heavens and the worlds within them." Because
this archê is no existing thing, but the source and foundation of them,
Anaximander names it the apeiron, by which he means that the archê is
indeterminate and has no characteristics: it is before and beyond all
distinctions made with respect to being. In the passage cited above,
Simplicius says that Anaximander was the first to name
the archê the apeiron (see Hippolytus, Refut. 1.5.). The Christian apologist
Hippolytus similarly explains Anaximander's position as follows: "This man
said that the originating principle of existing things is a certain constitution of
the Infinite (apeiron), out of which the heavens are generated, and the worlds
therein; and that this principle is eternal and undecaying, and comprising all
the worlds....This person declared the Infinite (apeiron) to be an originating
principle and element of existing things" (Refut. 1.5).

25. According to Simplicius (and previous interpreters), Anaximander reasons
that the first principle (archê) cannot be one of the elements derivative of it,
such as water: "It is clear that when he observed how the four elements
change into one another, he did not think it reasonable to conceive as one of
these as underlying the rest, but posited something else" (Phys. 24. 13). If all
four elements change into one another, then the first principle cannot be one
of these elements but must be prior to all of them; in other words, there must
be an source of the four elements that itself has no source, for only that which
is not any of the elements could give rise to them. It seems that Anaximander
put this forth as a necessary or logical truth: implicitly he is appealing to the
impossibility of infinite regress in explanation. Probably alluding to
Anaximander, Aristotle explains, "There are some people who make this [a
body distinct from the four elements] the infinite, and not air or water, in order
that the other elements may not be annihilated by the element which is
infinite. They have contrariety with each other—air is cold, water moist, fire
hot; if one were infinite, the others by now would have ceased to be. As it is,
they say, the infinite is different from them and is their source" (Physics.
204b). By "infinity" in this passage, Aristotle means temporal infinity. If any of
the elements were temporally infinite, and so the archê, there would no longer
be a balance between opposite elements, such as hot fire and cold earth,
because the one infinite element would never be transformed into its opposite,
but would remain eternally what it is. Instead, this infinite element would in the
long run destroy all the other elements without itself ever being destroyed.
In probable dependence upon Theophrastus' work, Simplicius explains that
in Anaximander's philosophy, the opposites emerge from the elements by
being separated from it. He writes, "There is another method, according to
which they do not attribute change to matter itself, nor do they suppose that
generation takes place by a transformation of the underlying substance, but
by separation; for the opposites existing in the substance which is infinite
matter are separated, according to Anaximander" (Phys. 32 r; 150, 20).
Likewise, Aristotle says of Anaximander's view: "The opposites are in the one
and are separated out" (Physics 187a 20). The idea of "separation" implies
that the opposites were already present in the apeironbut not evident as such,
because they were so thoroughly comingled with everything else. In other
words, everything already exists in the apeiron but not as detectable. This
means that the apeiron is not something different from the opposites that are
separated from it but is precisely these opposites not yet separated out but
mingled together. The second-century Christian theologian Irenaeus explains
Anaximander's position as follows: "Anaximander laid it down that infinitude
(the apeiron) is the first principle of all things, having seminally in itself the

26. generation of them all, and from this he declares the immense worlds [which
exist] were formed" (Adv. Haer. 2.14.2).
Anaximander may also have reasoned that there must be an infinite source
of all things, in order that, as Aristotle says, "Becoming might not fail"
(Physics. 203b 18; 208a 8). The apeiron is the undifferentiated source of all
things and, as such, is quantitatively infinite, because only as inexhaustible
could it be possible for becoming to continue indefinitely. In other words,
the apeiron is infinitely immense, having no limits on its volume. (Aristotle
refutes this idea, however, by pointing out that there is no need of an infinite
body to ensure perpetual becoming because "the passing away of one thing
may be the coming to be of another" [Physics 208a 8-9].)
2.2. Harmony of the Opposites
Dependent upon Theophrastus, Simplicius says according to Anaximander,
"Things perish into those things out of which they have their being, according
to necessity; for they make just recompense to one another for their injustice,
according to the ordinance [or assessment] of time—so he puts it in
somewhat poetical terms" (Phys. 24. 13). He means that from
the apeiron opposing pairs emerge (e.g., the wet/dry and the hot/cold) and
contend with one another, until one of the pair is annihilated, becoming the
other. For example, day will be transformed into night or winter into summer.
This is what Anaximander means when he says that things do injustices to
one another. (He is personifying the elements of nature, which is why
Simplicius says that Anaximander's language is poetic.) But when one thing
overcomes its opposite, the way is prepared for its own assimilation by its
resurgent opposite. Of necessity, the opposites are kept in balance, since the
origin of these forces is the apeiron, the source of all things, which includes all
opposites: the one by definition is unified and harmonious. So when day is
transformed into night, in time it will be transformed into day, and so the cycle
continues forever. This balance of opposing pairs is a reflection of the ultimate
harmony that governs the universe.
2.3. The Apeiron as Unconditioned and God
Anaximander identifies the apeiron as unconditioned and therefore as God.
Aristotle explains:
We cannot say that the apeiron has no effect, and the only effectiveness which we can ascribe to it is that
of a principle. Everything is either a source or derived from a source. But there cannot be a source of
the apeiron, for that would be a limit of it. Further, as it is a beginning, it is both uncreatable and
indestructible. For there must be a point at which what has come to be reaches completion, and also a

27. termination of all passing away. That is why, as we say, there is no principle of this, but it is this which is
held to be the principle of other things, and to encompass all and to steer all, as those assert who do not
recognize, alongside the infinite, other causes, such as Mind or Friendship. Further they identify it with the
Divine, for it is 'deathless and imperishable' as Anaximander says, with the majority of the physicists.
(Physics 3.4; 203b)
Everything is either as source or derived from a source. The apeiron is not
derived from a source, but is the one source of all things; if it were not, it
would no longer be the apeiron, for it would be conditioned or caused to be by
something else. It would therefore be something as distinct from other things
and not the source of all things. The apeiron is not anything, which is why it is
called the apeiron, the unlimited or indeterminate. While it is the source of all
that is created and destroyed, it is none of those things; if it were, it could not
be the source of those things. As the unlimited or indeterminate,
the apeiron not only does not come into being but also does not perish, for, if
it did, it would be limited or conditioned by that which can destroy it. To use
Aristotle's terminology, the apeiron is the (first) principle (archê) of all things,
which owes its existence to no other principle. Similarly, as already noted,
Hippolytus says that Anaximander's apeironas the archê "is eternal and
undecaying, and comprising all the worlds" (Refut. 1.5). Likewise, Aetius
reports, "Anaximander...says that the first principle of things is the apeiron; for
from this all things come, and all things perish and return to this" (Aet. 1.
3). Consistent with Greek assumptions, since it is "uncreatable and
indestructible," the apeiron must be God, for it is a assumed that whatever is
immortal is divine. Since it is god, the apeiron is no insentient volume of
matter, but is aware and has will, so that, as Aristotle says, it "steers all," by
which he means it gives direction to the unfolding of all things, which it itself
is. It does so while encompassing all (periechein), which seems to mean that
the apeiron surrounds the world and contains it.
Anaximenes (d. 528 BCE)

28. According to the surviving sources on his life, Anaximenes
flourished in the mid 6th century BCE and died around 528. He is the third philosopher of the
Milesian School of philosophy, so named because like Thales and Anaximander, Anaximenes was an
inhabitant of Miletus, in Ionia (ancient Greece). Theophrastusnotes that Anaximenes was an
associate, and possibly a student, of Anaximander‟s.
Anaximenes is best known for his doctrine that air is the source of all things. In this way, he differed
with his predecessors like Thales, who held that water is the source of all things, and Anaximander,
who thought that all things came from an unspecified boundless stuff.
Table of Contents
1. Doctrine of Air
2. Doctrine of Change
3. Origin of the Cosmos
4. Influence on later Philosophy
5. References and Further Reading
1. Doctrine of Air
Anaximenes seems to have held that at one time everything was air. Air can be thought of as a kind of
neutral stuff that is found everywhere, and is available to participate in physical processes. Natural
forces constantly act on the air and transform it into other materials, which came together to form
the organized world. In early Greek literature, air is associated with the soul (the breath of life) and
Anaximenes may have thought of air as capable of directing its own development, as the soul
controls the body (DK13B2 in the Diels-Kranz collection of Presocratic sources). Accordingly, he
ascribed to air divine attributes.
2. Doctrine of Change

29. Given his doctrine that all things are composed of air, Anaximenes suggested an interesting
qualitative account of natural change:
[Air] differs in essence in accordance with its rarity or density. When it is thinned it becomes fire, while
when it is condensed it becomes wind, then cloud, when still more condensed it becomes water, then
earth, then stones. Everything else comes from these. (DK13A5)
Using two contrary processes of rarefaction and condensation, Anaximenes explains how air is part
of a series of changes. Fire turns to air, air to wind, wind to cloud, cloud to water, water to earth and
earth to stone. Matter can travel this path by being condensed, or the reverse path from stones to fire
by being successively more rarefied. Anaximenes provides a crude kind of empirical support by
appealing to a simple experiment: if one blows on one‟s hand with the mouth relaxed, the air is hot;
if one blows with pursed lips, the air is cold (DK13B1). Hence, according to Anaximenes we see that
rarity is correlated with heat (as in fire), and density with coldness, (as in the denser stuffs).
Anaximenes was the first recorded thinker who provided a theory of change and supported it with
observation. Anaximander had described a sequence of changes that a portion of the boundless
underwent to form the different stuffs of the world, but he gave no scientific reason for changes, nor
did he describe any mechanism by which they might come about. By contrast, Anaximenes uses a
process familiar from everyday experience to account for material change. He also seems to have
referred to the process of felting, by which wool is compressed to make felt. This industrial process
provides a model of how one stuff can take on new properties when it is compacted.
3. Origin of the Cosmos
Anaximenes, like Anaximander, gives an account of how our world came to be out of previously
existing matter. According to Anaximenes, earth was formed from air by a felting process. It began as
a flat disk. From evaporations from the earth, fiery bodies arose which came to be the heavenly
bodies. The earth floats on a cushion of air. The heavenly bodies, or at least the sun and the moon,
seem also be flat bodies that float on streams of air. On one account, the heavens are like a felt cap
that turns around the head. The stars may be fixed to this surface like nails. In another account, the
stars are like fiery leaves floating on air (DK13A14). The sun does not travel under the earth but
circles around it, and is hidden by the higher parts of the earth at night.
Like Anaximander, Anaximenes uses his principles to account for various natural phenomena.
Lightning and thunder result from wind breaking out of clouds; rainbows are the result of the rays of
the sun falling on clouds; earthquakes are caused by the cracking of the earth when it dries out after
being moistened by rains. He gives an essentially correct account of hail as frozen rainwater.
Most commentators, following Aristotle, understand Anaximenes‟ theory of change as presupposing
material monism. According to this theory, there is only one substance, (in this case air) from which
all existing things are composed. The several stuffs: wind, cloud, water, etc., are only modifications of
the real substance that is always and everywhere present. There is no independent evidence to
support this interpretation, which seems to require Aristotle‟s metaphysical concepts of form and
matter, substratum and accident that are too advanced for this period. Anaximenes may have
supposed that the „stuffs‟ simply change into one another in order.

30. 4. Influence on later Philosophy
Anaximenes‟ theory of successive change of matter by rarefaction and condensation was influential
in later theories. It is developed by Heraclitus (DK22B31), and criticized by Parmenides (DK28B8.23-
24, 47-48). Anaximenes‟ general theory of how the materials of the world arise is adopted
by Anaxagoras(DK59B16), even though the latter has a very different theory of matter. Both Melissus
(DK30B8.3) and Plato (Timaeus 49b-c) see Anaximenes‟ theory as providing a common-sense
explanation of change. Diogenes of Apollonia makes air the basis of his explicitly monistic theory.
The Hippocratic treatise On Breaths uses air as the central concept in a theory of diseases. By
providing cosmological accounts with a theory of change, Anaximenes separated them from the
realm of mere speculation and made them, at least in conception, scientific theories capable of
testing.
5. References and Further Reading
There are no monographs on Anaximenes in English. Articles on him are sometimes rather
specialized in nature. A number of chapters in books on the Presocratics are helpful.
Anaximenes of Miletus
From Wikipedia, the free encyclopedia
Anaximenes of Miletus
Anaximenes (Greek: Άναξιμένηρ) of Miletus (b. 585 BCE, d. 528 BCE) was an Archaic
Greek Pre-Socratic philosopher active in the latter half of the 6th century BC. [1][2] One of the
three Milesian philosophers, he is identified as a younger friend or student
of Anaximander.[3][4] Anaximenes, like others in his school of thought, practiced material
monism.[5][4] This tendency to identify one specific underlying reality made up of a material
thing constitutes the bulk of the contributions for which Anaximenes is most famed.

31. Contents
[hide]
1 Anaximenes and the Arche
2 The Origin of the Cosmos
3 Other Phenomena
4 See also
5 References
6 Further reading
7 External links
[edit]Anaximenes and the Arche
While his predecessors Thales and Anaximander proposed that the arche, the underlying
material of the world, were water and the ambiguous substance apeiron, respectively,
Anaximenes asserted that air was this primary substance of which all other things are
made. While the choice of air may seem arbitrary, he based his conclusion on naturally
observable phenomena in the process of rarefaction and condensation.[6] When air
condenses it becomes visible, as mist and then rain and other forms of precipitation, and as
the condensed air cools Anixemenes supposed that it went on to form earth and ultimately
stones. In contrast, water evaporates into air which ignites and produces flame when further
rarefied.[7] While other philosophers also recognized such transitions in states of matter,
Anaximenes was the first to associate the quality pairs hot/dry and cold/wet with the density
of a single material and add a quantitative dimension to the Milesian monistic system. [7][8]
[edit]The Origin of the Cosmos
Having concluded that everything in the world is composed of air, Anaximenes then used
his theory to devise a scheme explaining the origins and nature of the earth as well as of
the surrounding celestial bodies. Air felted to create the flat disk of the earth, which he said
was table-like and behaved like a leaf floating on air. In keeping with the prevailing view of
celestial bodies as balls of fire in the sky, Anaximenes proposed that the earth let out an
exhalation of air that rarefied, ignited and became the stars. While the sun is similarly
described as being aflame, it is not composed of rarefied air like the stars but rather of earth
like the moon; its burning comes not from its composition but rather from its rapid
motion.[9] The moon and sun are likewise considered to be flat and floating on streams of
air, and when the sun sets it does not pass under the earth but is merely obscured by
higher parts of the earth as it circles around and becomes more distant; the motion of the

32. sun and the other celestial bodies around the earth is likened by Anaximenes to the way
that a cap may be turned around the head.[2][10]
[edit]Other Phenomena
Anaximenes used his observations and reasoning to provide causes for other natural
phenomena on the earth as well. Earthquakes he asserted were the result either of lack of
moisture, which causes the earth to break apart because of how parched it is, or of
overabundance thereof, which also causes cracks in the earth because of the excess of
water. In either case the earth becomes weakened by its cracks and hills collapse, causing
earthquakes. Lightning is also caused by a violent separation, this time of clouds by winds
to create a bright, fire-like flash. Rainbows are formed when densely compressed air is
touched by the rays of the sun.[11] These examples further show how Anaximenes like the
other Milesians looked for the broader picture in nature, seeking unifying causes for
diversely occurring events rather than treating each one on a case-by-case basis or
attributing them to gods or a personified nature.[5]
Thales
Mula sa Tagalog na Wikipedia, ang malayang ensiklopedya
Busto ni Thales

33. Si Thalis ng Milito (Griyego: Θαλήρ ο Μιλήσιορ, Thalis o Milisios, Tales ng Mileto), higit na kilala sa
anyong Latin ng kaniyang pangalan naThales, ay ipinanganak sa Ionia sa lungsod ng Milito (624 BK–546 BK)
ng Gresya noong mga 2500 taon na ang nakalilipas[1] sa baybayin ngDagat Egeo, anak nina Examio at
Cleobulina. Ang kaniyang mga pangunahing pasyon ay matematika, astronomiya, at politika. Itinuturing siya na
isa sa mga Pitong Paham ng Gresya. Siya rin ang kinikilala bilang unang dakilang siyentipiko. Siya ang unang
nakatuklas ng magnetismodahil sa pagkakatagpo niya na nakahahatak o nakaakit ng mga piraso ng bakal o
yero (iron sa Ingles) ang mineral na batong may balani(lodestone o loadstone sa Ingles). Kaugnay nito,
natuklasan niya rin ang kuryente dahil sa pagdikit ng magagaang na mga bagay sa mga piraso
ng amber (electron sa Griyego at pinagmulan ng salitang "elektrisidad" o electricity sa Ingles) pagkaraan
niyang kuskusin ang mga amber na ito.[1]
Thales of Miletus (c. 620 BCE – c. 546
BCE)
The ancient Greek philosopher Thales was born in Miletus in
Greek Ionia. Aristotle, the major source for Thales‟s philosophy and science, identified Thales as the
first person to investigate the basic principles, the question of the originating substances of matter
and, therefore, as the founder of the school of natural philosophy. Thales was interested in almost
everything, investigating almost all areas of knowledge, philosophy, history, science, mathematics,
engineering, geography, and politics. He proposed theories to explain many of the events of nature,
the primary substance, the support of the earth, and the cause of change. Thales was much involved
in the problems of astronomy and provided a number of explanations of cosmological events which
traditionally involved supernatural entities. His questioning approach to the understanding of
heavenly phenomena was the beginning of Greek astronomy. Thales‟ hypotheses were new and bold,
and in freeing phenomena from godly intervention, he paved the way towards scientific endeavor. He
founded the Milesian school of natural philosophy, developed the scientific method, and initiated the
first western enlightenment. A number of anecdotes is closely connected to Thales‟ investigations of
the cosmos. When considered in association with his hypotheses they take on added meaning and
are most enlightening. Thales was highly esteemed in ancient times, and a letter cited by Diogenes

34. Laertius, and purporting to be from Anaximenes to Pythagoras, advised that all our discourse should
begin with a reference to Thales (D.L. II.4).
1. The Writings of Thales
Doubts have always existed about whether Thales wrote anything, but a number of ancient reports
credit him with writings. Simplicius (Diels, Dox. p. 475) specifically attributed to Thales authorship
of the so-called Nautical Star-guide. Diogenes Laertius raised doubts about authenticity, but wrote
that „according to others [Thales] wrote nothing but two treatises, one On the Solstice and one On the
Equinox„ (D.L. I.23). Lobon of Argus asserted that the writings of Thales amounted to two hundred
lines (D.L. I.34), and Plutarch associated Thales with opinions and accounts expressed in verse
(Plutarch, De Pyth. or. 18. 402 E). Hesychius, recorded that „[Thales] wrote on celestial matters in
epic verse, on the equinox, and much else‟ (DK, 11A2). Callimachus credited Thales with the sage
advice that navigators should navigate by Ursa Minor (D.L. I.23), advice which may have been in
writing.
Diogenes mentions a poet, Choerilus, who declared that „[Thales] was the first to maintain the
immortality of the soul‟ (D.L. I.24), and in De Anima, Aristotle‟s words „from what is recorded about
[Thales]„, indicate that Aristotle was working from a written source. Diogenes recorded that „[Thales]
seems by some accounts to have been the first to study astronomy, the first to predict eclipses of the
sun and to fix the solstices; so Eudemus in his History of Astronomy. It was this which gained for
him the admiration of Xenophanes and Herodotus and the notice of Heraclitus and Democritus‟
(D.L. I.23). Eudemus who wrote a History of Astronomy, and also on geometry and theology, must
be considered as a possible source for the hypotheses of Thales. The information provided by
Diogenes is the sort of material which he would have included in his History of Astronomy, and it is
possible that the titles On the Solstice, and On the Equinox were available to Eudemus. Xenophanes,
Herodotus, Heraclitus and Democritus were familiar with the work of Thales, and may have had a
work by Thales available to them.
Proclus recorded that Thales was followed by a great wealth of geometers, most of whom remain as
honoured names. They commence with Mamercus, who was a pupil of Thales, and include Hippias of
Elis, Pythagoras, Anaxagoras, Eudoxus of Cnidus, Philippus of Mende, Euclid, and Eudemus, a
friend of Aristotle, who wrote histories of arithmetic, of astronomy, and of geometry, and many
lesser known names. It is possible that writings of Thales were available to some of these men.
Any records which Thales may have kept would have been an advantage in his own work. This is
especially true of mathematics, of the dates and times determined when fixing the solstices, the
positions of stars, and in financial transactions. It is difficult to believe that Thales would not have
written down the information he had gathered in his travels, particularly the geometry he
investigated in Egypt and his measuring of the height of the pyramid, his hypotheses about nature,
and the cause of change.
Proclus acknowledged Thales as the discoverer of a number of specific theorems (A Commentary on
the First Book of Euclid’s Elements 65. 8-9; 250. 16-17). This suggests that Eudemus, Proclus‟s
source had before him the written records of Thales‟s discoveries. How did Thales „prove‟ his
theorems if not in written words and sketches? The works On the Solstice, On the Equinox, which
were attributed to Thales (D.L. I.23), and the „Nautical Star-guide, to which Simplicius referred, may
have been sources for theHistory of Astronomy of Eudemus (D.L. I.23).
2. Possible Sources for Aristotle

35. There is no direct evidence that any written material of Thales was available to Plato and Aristotle,
but there is a surprisingly long list of early writers who could have known Thales, or had access to his
works, and these must be considered as possible sources for Plato, Aristotle, and the philosophers
and commentators who followed them. Aristotle‟s wording, „Thales says‟, is assertive wording which
suggests a reliable source, perhaps writings of Thales himself. Anaximander and Anaximenes were
associates of Thales, and would have been familiar with his ideas. Both produced written work.
Anaximander wrote in a poetical style (Theophr. ap. Simpl. Phys. fr. 2), and the writing of
Anaximenes was simple and unaffected (D.L. II.3). Other philosophers who were credited with
written works, who worked on topics similar to those of Thales, and who may have provided material
for later writers, are Heraclitus of Ephesus, Anaxagoras of Clazomenae, Alcmaeon, Hippo of Samos,
and Hippias of Elis.
3. Thales says Water is the Primary Principle
Aristotle defined wisdom as knowledge of certain principles and causes (Metaph. 982 a2-3). He
commenced his investigation of the wisdom of the philosophers who preceded him, with Thales, the
first philosopher, and described Thales as the founder of natural philosophy (Metaph. 983 b21-22).
He recorded: „Thales says that it is water‟. „it‟ is the nature, the archê, the originating principle. For
Thales, this nature was a single material substance, water. Despite the more advanced terminology
which Aristotle and Plato had created, Aristotle recorded the doctrines of Thales in terms which were
available to Thales in the sixth century BCE Aristotle made a definite statement, and presented it
with confidence. It was only when Aristotle attempted to provide the reasons for the opinions that
Thales held, and for the theories that he proposed, that he sometimes displayed caution.
4. Thales and Mythology
Those who believe that Thales inherited his views from Greek or Near-Eastern sources are wrong.
Thales was esteemed in his times as an original thinker, and one who broke with tradition and not as
one who conveyed existing mythologies. Aristotle unequivocally recorded Thales‟s hypothesis on the
nature of matter, and proffered a number of conjectures based on observation in favour of Thales‟s
declaration (Metaph. 983 b20-28). His report provided the testimony that Thales supplanted myth
in his explanations of the behaviour of natural phenomena. Thales did not derive his thesis from
either Greek or non-Greek mythological traditions.
Thales would have been familiar with Homer‟s acknowledgements of divine progenitors but he never
attributed organization or control of the cosmos to the gods. Aristotle recognized the similarity
between Thales‟s doctrine about water and the ancient legend which associates water with Oceanus
and Tethys, but he reported that Thales declared water to be the nature of all things. Aristotle
pointed to a similarity to traditional beliefs, not a dependency upon them. Aristotle did not call
Thales a theologian in the sense in which he designated „the old poets‟ (Metaph. 1091 b4) and others,
such as Pherecydes, as „mixed theologians‟ who did not use „mythical language throughout‟
(Metaph. 1091 b9). To Aristotle, the theories of Thales were so obviously different from all that had
gone before that they stood out from earlier explanations. Thales‟s views were not ancient and
primitive. They were new and exciting, and the genesis of scientific conjecture about natural
phenomena. It was the view for which Aristotle acknowledged Thales as the founder of natural
philosophy.
5. Thales’s Primary Principle

36. The problem of the nature of matter, and its transformation into the myriad things of which the
universe is made, engaged the natural philosophers, commencing with Thales. For his hypothesis to
be credible, it was essential that he could explain how all things could come into being from water,
and return ultimately to the originating material. It is inherent in Thales‟s hypotheses that water had
the potentiality to change to the myriad things of which the universe is made, the botanical,
physiological, meteorological and geological states. In Timaeus, 49B-C, Plato had Timaeus relate a
cyclic process. The passage commences with „that which we now call “water” „, and describes a theory
which was possibly that of Thales. Thales would have recognized evaporation, and have been familiar
with traditional views, such as the nutritive capacity of mist and ancient theories about spontaneous
generation, phenomena which he may have „observed‟, just as Aristotle believed he, himself had
(Hist. An. 569 b1; Gen. An. 762 a9-763 a34), and about which Diodorus Siculus (I.7.3-5; 1.10.6),
Epicurus (ap. Censorinus, D.N. IV.9), Lucretius (De Rerum Natura , V.783-808) and Ovid
(Met. I.416-437) wrote.
When Aristotle reported Thales‟s pronouncement that the primary principle is water, he made a
precise statement: „Thales says that it [the nature of things] is water‟ (Metaph. 983 b20), but he
became tentative when he proposed reasons which might have justified Thales‟s decision: „[Thales's]
supposition may have arisen from observation . . . „ (Metaph. 983 b22). It was Aristotle‟s opinion that
Thales may have observed, „that the nurture of all creatures is moist, and that warmth itself is
generated from moisture and lives by it; and that from which all things come to be is their first
principle‟ (Metaph. 983 b23-25). Then, in the lines 983 b26-27, Aristotle‟s tone changed towards
greater confidence. He declared: „Besides this, another reason for the supposition would be that the
semina of all things have a moist nature . . . „ (Metaph. 983 b26-27). In continuing the criticism of
Thales, Aristotle wrote: „That from which all things come to be is their first principle‟ (Metaph. 983
b25).
Simple metallurgy had been practised long before Thales presented his hypotheses, so Thales knew
that heat could return metals to a liquid state. Water exhibits sensible changes more obviously than
any of the other so-called elements, and can readily be observed in the three states of liquid, vapour
and ice. The understanding that water could generate into earth is basic to Thales‟s watery thesis. At
Miletus it could readily be observed that water had the capacity to thicken into earth. Miletus stood
on the Gulf of Lade through which the Maeander river emptied its waters. Within living memory,
older Milesians had witnessed the island of Lade increasing in size within the Gulf, and the river
banks encroaching into the river to such an extent that at Priene, across the gulf from Miletus the
warehouses had to be rebuilt closer to the water‟s edge. The ruins of the once prosperous city-port of
Miletus are now ten kilometres distant from the coast and the Island of Lade now forms part of a rich
agricultural plain. There would have been opportunity to observe other areas where earth generated
from water, for example, the deltas of the Halys, the Ister, about which Hesiod wrote (Theogony,
341), now called the Danube, the Tigris-Euphrates, and almost certainly the Nile. This coming-into-
being of land would have provided substantiation of Thales‟s doctrine. To Thales water held the
potentialities for the nourishment and generation of the entire cosmos. Aëtius attributed to Thales
the concept that „even the very fire of the sun and the stars, and indeed the cosmos itself is nourished
by evaporation of the waters‟ (Aëtius, Placita,I.3).
It is not known how Thales explained his watery thesis, but Aristotle believed that the reasons he
proposed were probably the persuasive factors in Thales‟s considerations. Thales gave no role to the
Olympian gods. Belief in generation of earth from water was not proven to be wrong until A.D. 1769
following experiments of Antoine Lavoisier, and spontaneous generation was not disproved until the
nineteenth century as a result of the work of Louis Pasteur.
6. New Ideas about the Earth

37. Thales proposed answers to a number of questions about the earth: the question of its support; its
shape; its size; and the cause of earthquakes; the dates of the solstices; the size of the sun and moon.
a. The Earth Floats on Water
In De Caelo Aristotle wrote: „This [opinion that the earth rests on water] is the most ancient
explanation which has come down to us, and is attributed to Thales of Miletus (Cael. 294 a28-30).
He explained his theory by adding the analogy that the earth is at rest because it is of the nature of
wood and similar substances which have the capacity to float on water, although not on air (Cael. 294
a30-b1). InMetaphysics (983 b21) Aristotle stated, quite unequivocally: „Thales . . . declared that the
earth rests on water‟. This concept does appear to be at odds with natural expectations, and Aristotle
expressed his difficulty with Thales‟s theory (Cael. 294 a33-294 b6).
Perhaps Thales anticipated problems with acceptance because he explained that it floated because of
a particular quality, a quality of buoyancy similar to that of wood. At the busy city-port of Miletus,
Thales had unlimited opportunities to observe the arrival and departure of ships with their heavier-
than-water cargoes, and recognized an analogy to floating logs. Thales may have envisaged some
quality, common to ships and earth, a quality of „floatiness‟, or buoyancy. It seems that Thales‟s
hypothesis was substantiated by sound observation and reasoned considerations. Indeed, Seneca
reported that Thales had land supported by water and carried along like a boat (Sen. QNat. III.14).
Aristotle‟s lines in Metaphysicsindicate his understanding that Thales believed that, because water
was the permanent entity, the earth floats on water.
Thales may have reasoned that as a modification of water, earth must be the lighter substance, and
floating islands do exist. Herodotus (The Histories, II.156) was impressed when he saw Chemmis, a
floating island, about thirty-eight kilometres north-east of Naucratis, the Egyptian trading
concession which Thales probably visited. Seneca described floating islands in Lydia: „There are
many light, pumice-like stones of which islands are composed, namely those which float in Lydia‟
(Sen. QNat., III.25. 7-10). Pliny described several floating islands, the most relevant being the Reed
Islands, in Lydia (HN,II.XCVII), and Pliny (the Younger) (Ep. VIII.XX) described a circular floating
island, its buoyancy, and the way it moved. Thales could have visited the near-by Reed Islands. He
might have considered such readily visible examples to be models of his theory, and he could well
have claimed that the observation that certain islands had the capacity to float substantiated his
hypothesis that water has the capacity to support earth.
Again it is understood that Thales did not mention any of the gods who were traditionally associated
with the simple bodies; we do not hear of Oceanus or Gaia: we read of water and earth. The idea that
Thales would have resurrected the gods is quite contrary to the bold, new, non-mythical theories
which Thales proposed.
b. Thales’s Spherical Earth
Modern commentators assume that Thales regarded the earth as flat, thin, and circular, but there is
no ancient testimony to support that opinion. On the contrary, Aristotle may have attributed
knowledge of the sphericity of the earth to Thales, an opinion which was later reported by Aëtius
(Aët. III. 9-10) and followed by Ps.-Plutarch (Epit. III.10). Aristotle wrote that some think it
spherical, others flat and shaped like a drum (Arist. Cael. 293 b33-294 a1), and then attributed belief
in a flat earth to Anaximenes, Anaxagoras, and Democritus (Arist. Cael. 294 b14-15). If following
chronological order, Aristotle‟s words, „some think it spherical‟, referred to the theory of Thales.

38. Aristotle then followed with the theory of Thales‟s immediate Milesian successor, Anaximander, and
then reported the flat earth view of Anaximenes, the third of the Milesian natural philosophers.
There are several good reasons to accept that Thales envisaged the earth as spherical. Aristotle used
these arguments to support his own view (Arist. Cael. 297 b25-298 a8). First is the fact that during a
solar eclipse, the shadow caused by the interposition of the earth between the sun and the moon is
always convex; therefore the earth must be spherical. In other words, if the earth were a flat disk, the
shadow cast during an eclipse would be elliptical. Second, Thales, who is acknowledged as an
observer of the heavens, would have observed that stars which are visible in a certain locality may
not be visible further to the north or south, a phenomena which could be explained within the
understanding of a spherical earth. Third, from mere observation the earth has the appearance of
being curved. From observation, it appears that the earth is covered by a dome. When observed from
an elevated site, the sky seems to surround the earth, like a dome, to meet the apparently curved
horizon. If observed over the seasons, the dome would appear to revolve, with many of the heavenly
bodies changing their position in varying degrees, but returning annually to a similar place in the
heavens. Through his work in astronomy Thales would almost certainly have become familiar with
the night sky and the motion of the heavenly bodies. There is evidence that he gave advice to navigate
by Ursa Minor, and was so involved in observation of the stars that he fell into a well. As a result of
observations made over a long period of time, Thales could have realized that the motions of the
fixed stars could not be explained within the idea of the observable hemispherical dome. During the
determination of the size of the rising sun, and again while watching its risings and settings during
his work on fixing the solstices, Thales may have realized that much natural phenomena could be
explained only within the understanding of the earth as a sphere.
From the shore, a ship can be seen to be descending, gradually, below the horizon, with the hull
disappearing from view first, to be followed by masts and sails. If one had a companion observing
from a higher point, the companion would see the ship for a long period before it disappeared from
view.
Aëtius recorded the different opinions of the shape of the earth that were held by Thales,
Anaximander and Anaximenes (III.9-10; III.10; and III.10). Cicero attributed to Thales the earliest
construction of a solid celestial globe (Rep. I.XIII.22). Thales‟s immediate successors proposed
theories about the shape of the earth which were quite different from each other, but that is no
reason to reject the view that Thales hypothesized a spherical earth. It is not the only occasion on
which Anaximander and Anaximenes failed to follow the theories of Thales. That they did not do so
is the main argument in favour of accepting that the scientific method commenced in the Milesian
School. There is testimony that Thales knew the earth to be spherical, but no evidence to suggest that
he proposed any other shape.
c. Earthquake Theory
Thales‟s theory about the cause of earthquakes is consistent with his hypothesis that earth floats
upon water. It seems that he applied his floating on water simile to the natural phenomena of
earthquakes. Aëtius recorded that Thales and Democritus found in water the cause of earthquakes
(Aët. III.15), and Seneca attributed to Thales a theory that on the occasions when the earth is said to
quake it is fluctuating because of the roughness of oceans (QNat. III.14; 6.6). Although the theory is
wrong, Thales‟s hypothesis is rational because it provides an explanation which does not invoke
hidden entities. It is an advance upon the traditional Homeric view that they resulted from an angry
supernatural god, Poseidon, shaking the earth through his rapid striding.

39. 7. All Things are Full of God
The question of whether Thales endowed the gods with a role in his theories is fundamental to his
hypotheses. The relevant text from Aristotle reads: „Thales, too, to judge from what is recorded of his
views, seems to suppose that the soul is in a sense the cause of movement, since he says that a stone
[magnet, or lodestone] has a soul because it causes movement to iron‟ (De An. 405 a20-22); „Some
think that the soul pervades the whole universe, whence perhaps came Thales‟s view that everything
is full of gods‟ (De An. 411 a7-8). In reference to the clause in the first passage „to judge from what is
recorded of his views‟, Snell convincingly argued that Aristotle had before him the actual sentence
recording Thales‟s views about the lodestone (Snell, 1944, 170). In the second passage the „some‟ to
whom Aristotle refers are Leucippus, Democritus, Diogenes of Apollonia, Heraclitus, and Alcmaeon,
philosophers who were later than Thales. They adopted and adapted the earlier view of Thales that
soul was the cause of motion, permeating and enlivening the entire cosmos. The order in which
Aristotle discussed Thales‟s hypothesis obscures the issue.
The source for Aristotle‟s report that Thales held all things to be full of gods is unknown, but some
presume that it was Plato. Thales is not mentioned in the relevant lines in Plato, but there is a
popular misconception that they refer to the belief of Thales. This is wrong. Thales had rejected the
old gods. In a passage in Apology(26 C) Socrates identified the heavenly bodies as gods, and pointed
out that that was the general understanding. In Cratylus(399 D-E) Plato had Socrates explain a
relationship between soul as a life-giving force, the capacity to breathe, and the reviving force.
In Timaeus 34B) Plato had Timaeus relate a theory which described soul as pervading the whole
universe. Then, in Laws Plato has the Athenian Stranger say: „Everyone . . . who has not reached the
utmost verge of folly is bound to regard the soul as a god. Concerning all the stars and the moon, and
concerning the years and months and all seasons, what other account shall we give than this very
same, – namely, that, inasmuch as it has been shown that they are all caused by one or more souls . .
. we shall declare these souls to be gods . . .? Is there any man that agrees with this view who will
stand hearing it denied that „all things are full of gods‟? The response is: „No man is so wrong-headed
as that‟ (Laws, 899 A-B). Plato had the Athenian Stranger extend his ideas into a theological theory.
He used a sleight of hand method to express his own ideas about divine spiritual beings. With the
exception of gods in the scheme of things, these passages reflect the beliefs which formed the
Thalean hypothesis, but Plato did not have the Athenian Stranger attribute the crucial clause „all
things are full of gods‟ to Thales. Thales is not mentioned.
Aristotle‟s text not the earliest extant testimony. Diogenes preserved a report from Hippias: „Aristotle
and Hippias affirm that, arguing from the magnet and from amber, [Thales] attributed a soul or life
even to inanimate objects‟ (D.L. I.24). This early report does not mention godly entities. The later
commentators, Cicero (Nat. D. I.X.25), and Stobaeus (Ecl. I.1.11) included gods in Thales‟s theory.
However, their views post-date Stoicism and are distorted by theistic doctrines.
Plato converted the idea of soul into a theory that „all things are full of gods‟, and this may have been
Aristotle‟s source, but the idea of gods is contrary to Thales‟s materialism. When Thales defined
reality, he chose an element, not a god. The motive force was not a supernatural being. It was a force
within the universe itself. Thales never invoked a power that was not present in nature itself, because
he believed that he had recognized a force which underpinned the events of nature.
8. Thales’s Astronomy
a. The Eclipse of Thales

40. Thales is acclaimed for having predicted an eclipse of the sun which occurred on 28 May 585 BCE
The earliest extant account of the eclipse is from Herodotus: „On one occasion [the Medes and the
Lydians] had an unexpected battle in the dark, an event which occurred after five years of indecisive
warfare: the two armies had already engaged and the fight was in progress, when day was suddenly
turned into night. This change from daylight to darkness had been foretold to the Ionians by Thales
of Miletus, who fixed the date for it within the limits of the year in which it did, in fact, take place‟
(Hdt. I.74). The vital points are: Thales foretold a solar eclipse; it did occur within the period he
specified. How Thales foretold the eclipse is not known but there is strong opinion that he was able
to perform this remarkable feat through knowledge of a cycle known as the Saros, with some
attributing his success to use of the Exeligmos cycle. It is not known how Thales was able to predict
the Eclipse, if indeed he did, but he could not have predicted the Eclipse by using the Saros or the
Exeligmos cycles.
In addition to Herodotus, the successful prediction of the eclipse was accepted by Eudemus in his
History of Astronomy and acknowledged by a number of other writers of ancient times (Cicero,
Pliny, Dercyllides, Clement, Eusebius). This is how Diogenes Laertius recorded the event: „[Thales]
seems by some accounts to have been the first to study astronomy, the first to predict eclipses of the
sun, and to fix the solstices; so Eudemus in his History of Astronomy. It was this which gained for
him the admiration of Xenophanes and Herodotus and the notice of Heraclitus and Democritus‟
(D.L. I.23). Diogenes asserted that Herodotus knew of Thales‟s work, and in naming Xenophanes,
Heraclitus, and Democritus, he nominated three of the great pre-Socratics, eminent philosophers
who were familiar with the work of Thales.
Modern astronomy confirms that the eclipse did occur, and was total. According to Herodotus‟s
report, the umbra of the eclipse of Thales must have passed over the battle field. The “un-
naturalness” of a solar eclipse is eerie and chilling. All becomes hushed and there is a strong uncanny
sensation of impending disaster, of being within the control of some awful power. In ancient times,
the awesome phenomenon must have aroused great fear, anxiety and wonder. The combatants saw
the eclipse as disapproval of their warfare, and as a warning. They ceased fighting and a peace
agreement was reached between the two kings.
It is not known why Thales turned away from the traditional beliefs which attributed all natural
events and man‟s fortunes and misfortunes to the great family of Olympian gods, but Miletus was the
most prosperous of the Ionian cities, and it cannot be doubted that the flourishing merchants
believed that their prosperity resulted from their own initiative and endeavours. Thales‟s great
philosophical pronouncement that water is the basic principle shows that Thales gave no
acknowledgement to the gods as instigators and controllers of phenomena. Thales‟s hypotheses
indicate that he envisaged phenomena as natural events with natural causes and possible of
explanation. From his new perspective of observation and reasoning, Thales studied the heavens and
sought explanations of heavenly phenomena.
It is widely accepted that Thales acquired information from Near-Eastern sources and gained access
to the extensive records which dated from the time of Nabonassar (747 BCE) and which were later
used by Ptolemy (Alm. III.7. H 254). Some commentators have suggested that Thales predicted the
solar eclipse of 585 BCE through knowledge of the Saros period, a cycle of 223 lunar months (18
years, 10-11 days plus 0.321124 of a day) after which eclipses both of the sun and moon repeat
themselves with very little change, or through knowledge of the Exeligmos cycle which is exactly
three times the length of the Saros (Ptolemy, Alm. IV.2. H270). The ancients could not have
predicted solar eclipses on the basis of those periodic cycles because eclipses of the sun do not repeat
themselves with very little change. The extra 0.321124 of a day means that each recurring solar
eclipse will be visible to the west, just under one-third of the circumference of the earth, being a
period of time of almost 7.7 hours. This regression to the west could not have been known to the

41. ancient astrologers, a fact which seems not to have been taken into account by the philosophers who
attribute Thales‟s success to application of one of those two cycles.
The following important fact should be noted. Some commentators and philosophers believe that
Thales may have witnessed the solar eclipse of 18th May 603 BCE or have had heard of it. They
accepted that he had predicted the solar eclipse of 28 May 585 BCE and reasoned from the
astronomical fact of the Saros cycles and the fact that the two solar eclipses had been separated by
the period of 18 years, 10 days, and 7.7 hours, and concluded that Thales had been able to predict a
solar eclipse based upon the knowledge of that cycle. Two facts discount rebut those claims. First,
recent research shows that the solar eclipse of 18th May 603 BCE would not have been visible in
Egypt, nor in the Babylonian observation cities where the astronomers watched the heavens for
expected and unusual heavenly events. The eclipse of 603 passed over the Persian Gulf, too far to the
south for observation (Stephenson, personal communication, March 1999; and Stephenson, “Long-
term Fluctuations”, 165-202). Even if the eclipse of 603 had been visible to the Near-Eastern
astronomers, it is not possible to recognize a pattern from witnessing one event, or indeed, from
witnessing two events. One may suggest a pattern after witnessing three events that are separated by
equal periods of time, but the eclipse which preceded that of 603, and which occurred on 6th May
621, was not visible in Near-Eastern regions. Consequently, it could not have been recorded by the
astrologer/priests who watched for unusual heavenly phenomena, and could not have been seen as
forming a pattern.
It is quite wrong to say that eclipses repeat themselves with very little change, because each solar
eclipse in a particular Saros occurs about 7.7 hours later than in the previous eclipse in the same
Saros, and that is about 1/3 of the circumference of the earth‟s circumference. Adding to the difficulty
of recognizing a particular cycle is the fact that about forty-two periodic cycles are in progress
continuously, and overlapping at any time. Every series in a periodic cycle lasts about 1,300 years
and comprises 73 eclipses. Eclipses which occur in one periodic cycle are unrelated to eclipses in
other periodic cycles.
The ancient letters prove that the Babylonians and Assyrians knew that lunar eclipses can occur only
at full moon, and solar eclipses only at new moon, and also that eclipses occur at intervals of five or
six months. However, while lunar eclipses are visible over about half the globe, solar eclipses are
visible from only small areas of the earth‟s surface. Recent opinion is that, as early as 650 BCE the
Assyrian astronomers seem to have recognized the six months-five months period by which they
could isolate eclipse possibilities (Steele, “Eclipse Prediction”, 429).
In other recent research Britton has analysed a text known as Text S, which provides considerable
detail and fine analysis of lunar phenomena dating from Nabonassar in 747 BCE The text points to
knowledge of the six-month five month periods. Britton believes that the Saros cycle was known
before 525 BCE (Britton, “Scientific Astronomy”, 62) but, although the text identifies a particular
Saros cycle, and graphically depicts the number of eclipse possibilities, the ancient commentary of
Text S does not attest to an actual observation (Britton, “An Early Function”, 32).
There is no evidence that the Saros could have been used for the prediction of solar eclipses in the
sixth century BCE, but it remains possible that forthcoming research, and the transliteration of more
of the vast stock of ancient tablets will prove that the Babylonians and Assyrians had a greater
knowledge of eclipse phenomena than is now known.
The Babylonian and Assyrian astronomers knew of the Saros period in relation to lunar eclipses, and
had some success in predicting lunar eclipses but, in the sixth century BCE when Thales lived and
worked, neither the Saros nor the Exeligmos cycles could be used to predict solar eclipses.

42. It is testified that Thales knew that the sun is eclipsed when the moon passes in front of it, the day of
eclipse – called the thirtieth by some, new moon by others (The Oxyrhynchus Papyri, 3710). Aëtius
(II.28) recorded: [Thales] says that eclipses of the sun take place when the moon passes across it in a
direct line, since the moon is earthy in character; and it seems to the eye to be laid on the disc of the
sun‟.
There is a possibility that, through analysis of ancient eclipse records, Thales identified another
cycle, the lunar eclipse-solar eclipse cycle of 23 1/2 months, the fact that a solar eclipse is a possibility
23 1/2months after a lunar eclipse. However, lunar eclipses are not always followed by solar eclipses.
Although the possibility is about 57% it is important to note that the total solar eclipse of 28th May,
585, occurred 23 1/2months after the total lunar eclipse of 4th July, 587. The wording of the report of
the eclipse by Herodotus: „Thales . . . fixed the date for the eclipse within the limits of the year‟ is
precise, and suggests that Thales‟s prediction was based upon a definite eclipse theory.
b. Setting the Solstices
A report from Theon of Smyrna ap. Dercyllides states that: „Eudemus relates in the Astronomy that
Thales was the first to discover the eclipse of the sun and that its period with respect to the solstices
is not always constant‟ (DK, 11 A 17). Diogenes Laertius (I.24) recorded that [Thales] was the first to
determine the sun‟s course from solstice to solstice, and also acknowledged the Astronomy of
Eudemus as his source.
Solstices are natural phenomena which occur on June 21 or 22, and December 21 or 22, but the
determination of the precise date on which they occur is difficult. This is because the sun seems to
„stand still‟ for several days because there is no discernible difference in its position in the sky. It is
the reason why the precise determination of the solstices was so difficult. It was a problem which
engaged the early astronomers, and more than seven centuries later, Ptolemy acknowledged the
difficulty (Alm. III.1. H203).
It is not known how Thales proceeded with his determination, but the testimony of Flavius
Philostratus is that: „[Thales] observed the heavenly bodies . . . from [Mount] Mycale which was close
by his home‟ (Philostratus, Life of Apollonius , II.V). This suggests that Thales observed the rising
and setting of the sun for many days at mid-summer and mid-winter (and, necessarily, over many
years). Mount Mycale, being the highest point in the locality of Miletus, would provide the perfect
vantage point from which to make observations. Another method which Thales could have employed
was to measure the length of the noon-day sun around mid-summer and mid-winter. Again this
would require observations to be made, and records kept over many days near the solstice period,
and over many years.
c. Thales’s Discovery of the Seasons
From Diogenes Laertius we have the report: „[Thales] is said to have discovered the seasons of the
year and divided it into 365 days‟ (D.L. I.27). Because Thales had determined the solstices, he would
have known of the number of days between say, summer solstices, and therefore have known the
length of a solar year. It is consistent with his determination of the solstices that he should be
credited with discovering that 365 days comprise a year. It is also a fact that had long been known to
the Egyptians who set their year by the more reliable indicator of the annual rising of the star Sirius
in July. Thales may have first gained the knowledge of the length of the year from the Egyptians, and
perhaps have attempted to clarify the matter by using a different procedure. Thales certainly did not
„discover‟ the seasons, but he may have identified the relationship between the solstices, the

43. changing position during the year of the sun in the sky, and associated this with seasonal climatic
changes.
d. Thales’s Determination of the Diameters of the Sun
and the Moon
Apuleius wrote that „Thales in his declining years devised a marvellous calculation about the sun,
showing how often the sun measures by its own size the circle which it describes‟. (Apul. Florida, 18).
Following soon after Apuleius, Cleomedes explained that the calculation could be made by running a
water-clock, from which the result was obtained: the diameter of the sun is found to be one seven-
hundred-and-fiftieth of its own orbit (Cleomedes, De Motu circulari corporum caelestium, II.75).
The third report is from Diogenes: „According to some [Thales was] the first to declare the size of the
sun to be one seven hundred and twentieth part of the solar circle, and the size of the moon to be the
same fraction of the lunar circle‟ (D.L. I.24). Little credence can be given to the water-clock method
for reaching this determination, because there is an inbuilt likelihood of repeated errors over the 24
hour period. Even Ptolemy, who flourished in the second century A.D., rejected all measurements
which were made by means of water-clocks, because of the impossibility of attaining accuracy by
such means (Alm. V.14. H416).
In his work in geometry, Thales was engaged in circles and angles, and their characteristics, and he
could have arrived at his solution to the problem by applying the geometrical knowledge he had
acquired. There is no evidence to support a suggestion that Thales was familiar with measurements
by degrees but he could have learnt, from the Babylonians, that a circle is divided into 3600. The
figure of 720, which was given by Diogenes for Thales, is double 360, and this is related to the
Babylonian sexagesimal system. To establish the dates of the solstices, Thales probably made
repeated observations of the risings and settings of the sun. From such experiments he could have
observed that the angle which was subtended by the elevation of the rising sun is 1/20 and with 3600
in a circle, the ratio of 1:720 is determined.
Of the report from Diogenes Laertius (D.L. I.24) that Thales also determined the orbit of the moon in
relation to the size of its diameter, Thales would repeat the method to calculate the orbit of the
moon.
e. Ursa Minor
Callimachus (D.L. I.22) reported that Thales „discovered‟ Ursa Minor. This means only that he
recognized the advantages of navigating by Ursa Minor, rather than by Ursa Major, as was the
preferred method of the Greeks. Ursa Minor, a constellation of six stars, has a smaller orbit than
does the Great Bear, which means that, as it circles the North Pole, Ursa Minor changes its position
in the sky to a lesser degree than does the Great Bear. Thales offered this sage advice to the mariners
of Miletus, to whom it should have been of special value because Miletus had developed a maritime
trade of economic importance.
f. Falling into a Well
In Theaetetus (174 A) Plato had Socrates relate a story that Thales was so intent upon watching the
stars that he failed to watch where he was walking, and fell into a well. The story is also related by
Hippolytus (Diels, Dox. 555), and by Diogenes Laertius (D.L. II.4-5). Irony and jest abound in Plato‟s

44. writing and he loved to make fun of the pre-Socratics, but he is not likely to have invented the
episode, especially as he had Socrates relate the event. Aristotle wrote that viewing the heavens
through a tube „enables one to see further‟ (Gen. An. 780 b19-21), and Pliny (HN, II.XI) wrote that:
„The sun‟s radiance makes the fixed stars invisible in daytime, although they are shining as much as
in the night, which becomes manifest at a solar eclipse and also when the star is reflected in a very
deep well‟. Thales was renowned and admired for his astronomical studies, and he was credited with
the „discovery‟ of Ursa Minor (D.L. I.23). If Thales had heard that stars could be viewed to greater
advantage from wells, either during day or night, he would surely have made an opportunity to test
the theory, and to take advantage of a method that could assist him in his observations. The
possibility that the story was based on fact should not be overlooked. Plato had information which
associated Thales with stars, a well, and an accident. Whether Thales fell into a well, or tripped when
he was getting in or out of a well, the story grew up around a mishap.
9. Mathematics
The practical skill of land measurement was invented in Egypt because of the necessity frequently to
remeasure plots of land after destructive inundations. The phenomena is well described by
Herodotus (II.93-109). Egypt was believed to be the source of much wisdom and reports tell us that
many Greeks, including Thales, Pythagoras, Solon, Herodotus, Plato, Democritus, and Euclid, visited
that ancient land to see the wonders for themselves.
The Egyptians had little to offer in the way of abstract thought. The surveyors were able to measure
and to calculate and they had outstanding practical skills. In Egypt Thales would have observed the
land surveyors, those who used a knotted cord to make their measurements, and were known as
rope-stretchers. Egyptian mathematics had already reached its heights when The Rhind
Mathematical Papyrus was written in about 1800 BCE More than a thousand years later, Thales
would have watched the surveyors as they went about their work in the same manner, measuring the
land with the aid of a knotted rope which they stretched to measure lengths and to form angles.
The development of geometry is preserved in a work of Proclus, A Commentary on the First Book of
Euclid’s Elements (64.12-65.13). Proclus provided a remarkable amount of intriguing information,
the vital points of which are the following: Geometry originated in Egypt where it developed out of
necessity; it was adopted by Thales who had visited Egypt, and was introduced into Greece by him
The Commentary of Proclus indicates that he had access to the work of Euclid and also to The
History of Geometry which was written by Eudemus of Rhodes, a pupil of Aristotle, but which is no
longer extant. His wording makes it clear that he was familiar with the views of those writers who
had earlier written about the origin of geometry. He affirmed the earlier views that the rudiments of
geometry developed in Egypt because of the need to re-define the boundaries, just as Herodotus
stated.
a. The Theorems Attributed to Thales
Five Euclidean theorems have been explicitly attributed to Thales, and the testimony is that Thales
successfully applied two theorems to the solution of practical problems.
Thales did not formulate proofs in the formal sense. What Thales did was to put forward certain
propositions which, it seems, he could have „proven‟ by induction: he observed the similar results of
his calculations: he showed by repeated experiment that his propositions and theorems were correct,
and if none of his calculations resulted in contrary outcomes, he probably felt justified in accepting

45. his results as proof. Thalean „proof‟ was often really inductive demonstration. The process Thales
used was the method of exhaustion. This seems to be the evidence from Proclus who declared that
Thales „attacked some problems in a general way and others more empirically‟.
DEFINITION I.17: A diameter of the circle is a straight line drawn through the centre and terminated
in both directions by the circumference of the circle; and such a straight line also bisects the circle
(Proclus, 124). >
PROPOSITION I.5: In isosceles triangles the angles at the base are equal; and if the equal straight
lines are produced further, the angles under the base will be equal (Proclus, 244). It seems that
Thales discovered only the first part of this theorem for Proclus reported: We are indebted to old
Thales for the discovery of this and many other theorems. For he, it is said, was the first to notice and
assert that in every isosceles the angles at the base are equal, though in somewhat archaic fashion he
called the equal angles similar (Proclus, 250.18-251.2).
PROPOSITION I.15: „If two straight lines cut one another, they make the vertical angles equal to one
another‟ (Proclus, 298.12-13). This theorem is positively attributed to Thales. Proof of the theorem
dates from the Elements of Euclid (Proclus, 299.2-5).
PROPOSITION I.26: „If two triangles have the two angles equal to two angles respectively, and one
side equal to one side, namely, either the side adjoining the equal angles, or that subtending one of
the equal angles, they will also have the remaining sides equal to the remaining sides and the
remaining angle equal to the remaining angle‟ (Proclus, 347.13-16). „Eudemus in his history of
geometry attributes the theorem itself to Thales, saying that the method by which he is reported to
have determined the distance of ships at sea shows that he must have used it‟ (Proclus, 352.12-15).
Thales applied this theorem to determine the height of a pyramid. The great pyramid was already
over two thousand years old when Thales visited Gizeh, but its height was not known. Diogenes
recorded that „Hieronymus informs us that [Thales] measured the height of the pyramids by the
shadow they cast, taking the observation at the hour when our shadow is of the same length as
ourselves‟ (D.L. I.27). Pliny (HN, XXXVI.XVII.82) and Plutarch (Conv. sept. sap. 147) also recorded
versions of the event. Thales was alerted by the similarity of the two triangles, the „quality of
proportionality‟. He introduced the concept of ratio, and recognized its application as a general
principle. Thales‟s accomplishment of measuring the height of the pyramid is a beautiful piece of
mathematics. It is considered that the general principle in Euclid I.26 was applied to the ship at sea
problem, would have general application to other distant objects or land features which posed
difficulties in the calculation of their distances.
PROPOSITION III.31: „The angle in a semicircle is a right angle‟. Diogenes Laertius (I.27) recorded:
„Pamphila states that, having learnt geometry from the Egyptians, [Thales] was the first to inscribe a
right-angled triangle in a circle, whereupon he sacrificed an ox‟. Aristotle was intrigued by the fact
that the angle in a semi-circle is always right. In two works, he asked the question: „Why is the angle
in a semicircle always a right angle?‟ (An. Post. 94 a27-33; Metaph. 1051 a28). Aristotle described the
conditions which are necessary if the conclusion is to hold, but did not add anything that assists with
this problem.
It is testified that it was from Egypt that Thales acquired the rudiments of geometry. However, the
evidence is that the Egyptian skills were in orientation, measurement, and calculation. Thales‟s
unique ability was with the characteristics of lines, angles and circles. He recognized, noticed and
apprehended certain principles which he probably „proved‟ through repeated demonstration.
10. Crossing the Halys

46. Herodotus recorded „the general belief of the Greeks‟ that Thales assisted Croesus in transporting his
troops across the Halys river (Hdt. I.75) on his advance into Capadoccia to engage the great Persian
conqueror, Cyrus who threatened from the east. Herodotus provided a detailed description of the
reported crossing which many of the Greeks supposed had been accomplished through Thales‟s
engineering skills and ingenuity (Hdt. I.75). Herodotus had been told that Thales advised Croesus to
divide the river into two parts. The story is that Thales directed the digging so that the river was
diverted into two smaller streams, each of which could then be forded. The story from Herodotus
describes a formation similar to an oxbow lake. The work could have been undertaken by the men of
Croesus‟s army, and directed by Thales. With both channels then being fordable, Croesus could lead
his army across the Halys. This description complies with „the general belief of the Greeks‟ which
Herodotus related.
However, Herodotus did not accept that story, because he believed that bridges crossed the river at
that time (I.74). Herodotus‟s misgivings were well founded. There is considerable support for the
argument that Croesus and his army crossed the Halys by the bridge which already existed and
travelled by the Royal Road which provided the main access to the East. Herodotus explained that at
the Halys there were gates which had to be passed before one crossed the river, which formed the
border, with the post being strongly guarded (Hdt. V.52).
The town of Cesnir Kopru, or Tcheshnir Keupreu, is a feasible site for a crossing. Before the
industrialization of the area, a mediaeval bridge was observed, underneath which, when the river was
low, could be seen not only the remains of its Roman predecessor but the roughly hewn blocks of a
much earlier bridge (Garstang, 1959, 2). Any clues that may have helped to provide an answer to the
question of whether there were bridges in the time of Croesus are now submerged by the
hydroelectric plants which have been built in the area. Herodotus recorded the details that he had
obtained, but used his own different understanding of the situation to discount the report.
11. The Possible Travels of Thales
Establishing whether or not Thales travelled and what countries he visited is important because we
may be able to establish what information he could have acquired from other sources.
In Epinomis 987 E) Plato made the point that the Greeks took from foreigners what was of value and
developed their notions into better ideas.
Eudemus, who was one of Aristotle‟s students, believed that Thales had travelled to Egypt (Eudemus
ap. Proclus, 65.7). A number of ancient sources support that opinion, including Pamphila who held
that he spent time with the Egyptian priests (D.L. I.24), Hieronymus from whose report we learn
that Thales measured the height of the pyramids by the shadow they cast (D.L. I.27), and Plutarch
(De Is. et Os. 131). Thales gave an explanation for the inundation (D.L. I.37). He may have devised
this explanation after witnessing the phenomena, which Herodotus later described (Hdt. II.97).
By 620 BCE, and perhaps earlier, Miletus held a trading concession at Naucratis (Hdt. II.178, Strab.
17.1.18) on the Canopic mouth of the Nile, and it is possible that Thales visited Egypt on a trading
mission. Travel to Egypt would not have been difficult. Homer had Ulysses sailing from Crete to the
Nile in five days, and Ernle Bradford recently made a similar journey, proving the trip to be feasible
(Bradford, Ulysses Found, 26, and passim). The wealth of Miletus was the result of its success as a
trading centre, and there would have been no difficulty in arranging passage on one of the many
vessels which traded through of Miletus.
Josephus (Contra Apionem I.2) wrote that Thales was a disciple of the Egyptians and the Chaldeans
which suggests that he visited the Near-East. It is thought that Thales visited the Babylonians and

47. Chaldeans and had access to the astrological records which enabled him to predict the solar eclipse
of 585 BCE
Miletus had founded many colonies around the Mediterranean and especially along the coasts of the
Black Sea. Pliny (HN, V.31.112) gives the number as ninety. The Milesians traded their goods for raw
materials, especially iron and timber, and tunny fish. Strabo made mention of „a sheep-industry‟, and
the yield of „soft wool‟ (Strabo, 12.3.13), and Aristophanes mentioned the fine and luxurious Milesian
wool (Lysistrata, 729; Frogs, 543). The Milesian traders had access to the hinterland. The land
around the mouth of the Halys was fertile, „productive of everything . . . and planted with olive trees‟
(Strabo, 12.3.12-13). Thales was associated with a commercial venture in the production of olive oil in
Miletus and Chios, but his interests may have extended beyond those two places. Olive oil was a basic
item in the Mediterranean diet, and was probably a trading commodity of some importance to
Milesian commerce.
It is likely that Thales was one of the „great teachers‟ who, according to Herodotus, visited Croesus in
the Lydian capital, Sardis (Hdt. I.30). From Sardis, he could have joined a caravan to make the three-
month journey along the well used Royal Road (Hdt. V.53), to visit the observatories in Babylonia,
and seek the astronomical knowledge which they had accumulated over centuries of observation of
heavenly phenomena. In about 547 BCE late in his life, Thales travelled into Cappadocia with
Croesus, and, according to some belief, devised a scheme by which the army of Croesus was able to
cross the River Halys. Milesian merchantmen continually plied the Black Sea, and gaining a passage
could have been easily arranged. From any number of ports Thales could have sought information,
and from Sinope he may have ventured on the long journey to Babylonia, perhaps travelling along
the valley of the Tigris, as Xenophon did in 401-399 BCE
In a letter purported to be from Thales to Pherecydes, Thales stated that he and Solon had both
visited Crete, and Egypt to confer with the priests and astronomers, and all over Hellas and Asia
(D.L. I.43-44). All that should be gleaned from such reports, is that travel was not exceptional, with
many reports affirming the visits of mainly notable people to foreign lands. Alcaeus visited Egypt‟
(Strabo, 1.2.30), and his brother, Antimenidas, served in Judaea in the army of the Babylonian
monarch, King Nebuchadrezzar. Sappho went into exile in Sicily, her brother,Charaxus, spent some
time in Egypt, and a number of friends of Sappho visited Sardis where they lived in Lydian society.
There must have been any number of people who visited foreign lands, about whom we know
nothing.
Very little about the travels of Thales may be stated with certainty, but it seems probable that he
would have sought information from any sources of knowledge and wisdom, particularly the centres
of learning in the Near-East. It is accepted that there was ample opportunity for travel.
12. Milesian School
Thales was the founder of a new school of philosophy (Arist. Metaph. 983 b20). His two fellow
Milesians who also engaged in the new questioning approach to the understanding of the universe,
were Anaximander, his disciple (D.L. I.13), and Anaximenes, who was the disciple of Anaximander
(D.L. II.2). Anaximander was about ten years younger than Thales, but survived him by only a year,
dying in about 545. Anaximenes was born in 585 and died in about 528. Their lives all overlapped.
Through their association they comprised the Milesian School: They all worked on similar problems,
the nature of matter and the nature of change, but they each proposed a different material as the
primary principle, which indicates that there was no necessity to follow the master‟s teachings or
attribute their discoveries to him. Each proposed a different support for the earth. Thales was held in
high regard for his wisdom, being acclaimed as the most eminent of the Wise Men of Ancient Greece,

48. but he was not regarded as a god, as Pythagoras was. Anaximander and Anaximenes were free to
pursue their own ideas and to express them in writing. This surely suggests that they engaged in
critical discussion of the theories of each other. The Greeks are a sociable people, and their
willingness to converse brought rewards in knowledge gained, as Plato remarked (Epinomis, 987E).
Critical discussion implies more than familiarity with other views, and more than mere disagreement
with other theories. It is the adoption, or in this case, the development, of a new style of discussion.
It is a procedure which encourages questioning, debate, explanation, justification and criticism.
There was a unique relationship between the three Milesians and it is highly probable that the
critical method developed in the Milesian School under the leadership of Thales.
13. The Seven Sages of Ancient Greece
The earliest reference to the Seven Sages of Ancient Greece is in Plato‟s Protagoras in which he listed
seven names: „A man‟s ability to utter such remarks [notable, short and compressed] is to be ascribed
to his perfect education. Such men were Thales of Miletus, Pittacus of Mitylene, Bias of Priene, Solon
of our city [Athens], Cleobulus of Lindus, Myson of Chen, and, last of the traditional seven, Chilon of
Sparta. . . . and you can recognize that character in their wisdom by the short memorable sayings that
fell from each of them‟ (Protagoras, 342 E-343 A).
Diogenes recorded that „Thales was the first to receive the name of Sage in the archonship of
Damasias at Athens, when the term was applied to all the Seven Sages, as Demetrius of Phalerum
[born. ca. 350 B.C] mentions in his List of Archons (D.L. I.22). Demetrius cannot have been the
source for Plato, who died when Demetrius was only three years old. Perhaps there was a source
common to both Plato and Demetrius, but it is unknown.
Damasias was archon in 582/1. It may be significant that at this time the Pythian Games were re-
organized. More events were added and, for the first time, they were to be held at intervals of four
years, in the third year of the Olympiad, instead of the previous eight-yearly intervals. Whether there
is an association between the re-organization of the Pythian Games and the inauguration of the
Seven Sages in not known but, as Pausanias indicates, the Seven were selected from all around
Greece: „These [the sages] were: from Ionia, Thales of Miletus and Bias of Priene; of the Aeolians in
Lesbos, Pittacus of Mitylene; of the Dorians in Asia, Cleobulus of Lindus; Solon of Athens and Chilon
of Sparta; the seventh sage, according to the list of Plato, the son of Ariston is not Periander, the son
of Cypselus, but Myson of Chenae, a village on Mount Oeta‟ (Paus. 14.1). The purpose of Damasias
may have been aimed at establishing unity between the city-states.
It is difficult to believe that the Seven all assembled at Delphi, although the dates just allow it. Plato
wrote that their notable maxims were featured at Delphi: „They [the Sages], assembled together and
dedicated these [short memorable sayings] as the first-fruits of their lore to Apollo in his Delphic
temple, inscribing there those maxims which are on every tongue – “Know thyself‟ and “Nothing
overmuch” „ (Pl. Prt. 343 A-B).
Plato regarded wise maxims as the most essential of the criteria for a sage, and associated them with
wisdom and with good education, but he has Socrates say: „Think again of all the ingenious devices in
arts or other achievements, such as you might expect in one of practical ability; you might remember
Thales of Miletus and Anacharsis the Scythian‟ (Respublica , 600 A). Practical ability was clearly
important.
Several other lists were compiled: Hippobotus (D.L. I.42); Pittacus (D.L. I.42); and Diogenes (D.L.
I.13. They omitted some names and adding others. In his work On the Sages, Hermippus reckons
seventeen, which included most of the names listed by other compilers.

49. Many commentators state that Thales was named as Sage because of the practical advice he gave to
Miletus in particular, and to Ionia in general. The earlier advice was to his fellow Milesians. In 560,
the thirty-five year old Croesus (Hdt. I.25) succeeded his father Alyattes and continued the efforts
begun by his father to subdue the Milesians, but without success. Diogenes tells us that „when
Croesus sent to Miletus offering terms of alliance, [Thales] frustrated the plan‟ (D.L. I.25). The
second occasion was at an even later date, when the power of Cyrus loomed as a threat from the east.
Thales‟s advice to the Ionian states was to unite in a political alliance, so that their unified strength
could be a defence against the might of Cyrus. This can hardly have been prior to 550 BCE which is
thirty years later than the promulgation of the Seven Sages. Thales was not named as a Sage because
of any political advice which is extant.
One of the few dates in Thales‟s life which can be known with certainty is the date of the Eclipse of
585 BCE It brought to a halt the battle being fought between Alyattes and the Mede, Cyaxares and, in
addition, brought peace to the region after „five years of indecisive warfare‟ (Hdt. I.74). The Greeks
believed that Thales had predicted the Eclipse, and perhaps even regarded him as being influential in
causing the phenomenon to occur. This was reason enough to declare Thales to be a man of great
wisdom and to designate him as the first of the Seven Sages of Ancient Greece.
14. Corner in Oil
Thales‟s reputation for wisdom is further enhanced in a story which was related by Aristotle.
(Politics,1259 a 6-23). Somehow, through observation of the heavenly bodies, Thales concluded that
there would be a bumper crop of olives. He raised the money to put a deposit on the olive presses of
Miletus and Chios, so that when the harvest was ready, he was able to let them out at a rate which
brought him considerable profit. In this way, Thales answered those who reproached him for his
poverty. As Aristotle points out, the scheme has universal application, being nothing more than a
monopoly. There need not have been a bumper harvest for the scheme to have been successful. It is
quite likely that Thales was involved in commercial ventures, possibly the export of olive oil, and
Plutarch reported that Thales was said to have engaged in trade (Plut. Vit. Sol. II.4).
15. The Heritage of Thales
Thales is the first person about whom we know to propose explanations of natural phenomena which
were materialistic rather than mythological or theological. His theories were new, bold, exciting,
comprehensible, and possible of explanation. He did not speak in riddles as did Heraclitus, and had
no need to invent an undefined non-substance, as Anaximander did. Because he gave no role to
mythical beings, Thales‟s theories could be refuted. Arguments could be put forward in attempts to
discredit them. Thales‟s hypotheses were rational and scientific. Aristotle acknowledged Thales as
the first philosopher, and criticized his hypotheses in a scientific manner.
The most outstanding aspects of Thales‟s heritage are: The search for knowledge for its own sake; the
development of the scientific method; the adoption of practical methods and their development into
general principles; his curiosity and conjectural approach to the questions of natural phenomena –
In the sixth century BCE Thales asked the question, „What is the basic material of the cosmos?‟ The
answer is yet to be discovered.