In the beginning there was only Chaos, the
But then Gaia, the Earth, came into being,
Her broad bosom the ever-ﬁrm foundation of
And Tartaros, dim in the underground depths,
And Eros, loveliest of all the Immortals, who
Makes their bodies (and men’s bodies) go limp,
Mastering their minds and subduing their wills.
Thales of Miletus
~624 to ~546 BCE
“Western philosophy began with
Thales” (Bertrand Russell, 1945)
Natural explanations for
observed events, e.g. earthquakes
What is the “ﬁrst
principle” (arche) from which all
things are made?
Is change real? What causes it?
~610 to ~ 546 BCE
Accepts material monism but
Aperion is in motion and splits
into hot (ﬁre) and cold (air &
Change occurs due to law-like
~610 to ~ 546 BCE
“[T]he ﬁrst animals were produced
in moisture, enclosed in thorny
barks ... they came out onto the
“Humans were born from other
kinds of animals”
“[T]here arose from heated water
and earth either ﬁsh of animals very
like ﬁsh. In these, humans grew ...”
died 528 BCE
Aer rareﬁes to become Fire
Aer condenses to form wind
(then cloud, water, earth &
Commitment to argument and critical inquiry, together
with a view about the nature of justiﬁcation
Commitment to the idea that the natural world could
be explained in terms that do not refer to anything
beyond nature itself
Pythagoras of Samos
~570 to ~495 BCE
Akousmatikoi (“listeners”) saw him as
a religious and ethical leader
Mathematikoi (“learners”) studied
philosophy, mathematics, astronomy,
Mathematics was key to
understanding the kosmos
~535 to ~475 BCE
Τα Πάντα ῥεῖ - “Everything ﬂows”
The logos (account, word) was the
single divine law of the universe that
governs all change and we can come
to understand it.
Logos manifests itself as ﬁre, always
changing yet always the same.
Born ~515 BCE?
The world as it appears is false.
Change is impossible, and existence is
timeless, uniform, and unchanging.
Clear inﬂuence on Plato.
~460 to ~370 BCE
There is no purpose (telos),
prime mover or ﬁnal cause
involving indestructible atoms.
The universe is composed of
nothing but tiny atoms
churning which collide
together to form larger units.
A Stationary Earth
“The LORD is king, robed with majesty; the LORD is robed,
girded with might. The world will surely stand in place, never
to be moved.” [Psalms 93:1]
“The LORD is king. The world will surely stand fast, never to
be moved. God rules the peoples with fairness.” [Psalms 96:
“You ﬁxed the earth on its foundation, never to be
moved.” [Psalms 104: 5]
“Tremble before him, all the earth; he has made the world
ﬁrm, not to be moved.” (1 Chronicles 16: 30]
A Mobile Sun
“Then spake Joshua to the LORD in the day when
the LORD delivered up the Amorites before the
children of Israel, and he said in the sight of Israel,
Sun, stand thou still upon Gibeon; and thou, Moon,
in the valley of Ajalon. And the sun stood still, and
the moon stayed, until the people had avenged
themselves upon their enemies. Is not this written
in the book of Jasher? So the sun stood still in the
midst of heaven, and hasted not to go down about a