Western philosophy is considered generally to have begun in ancient Greece as speculation about the
underlying nature of the physical world. In its earliest form it was indistinguishable from natural science.
In the earliest philosophers of Greece it is impossible to separate ideas of divinity and the human soul from
ideas about the mystery of being and the genesis of material change.
Philosophy among the Greeks slowly emerged out of religious awe into wonder about the principles and
elements of the natural world.
Eventually, cosmological speculation partly gave way to moral and political theorizing.
As the Greek populations left the land to become concentrated in their cities, interest shifted from nature to
social living; questions of law and convention and civic values became paramount.
The three greatest Greek philosophers are Socrates, Plato, and Aristotle. All philosophers and schools prior to
Socrates are generally referred to as the Pre-Socratics.
The Ionian School
Also known as the Milesian School.
Among other things, the Ionian school made the initial radical step from mythological to scientific explanation
of natural phenomena.
It discovered the important scientific principles of the permanence of substance, the natural evolution of the
world, and the reduction of quality to quantity.
Thales of Miletus (early 6th
century BC) was the first philosopher of historical record.
He founded the first important school of Greek philosophy in the city of Miletus on the Ionian coast of Asia
Thales was revered by later generations as one of the Seven Wise Men of Greece; he was interested in
astronomical, physical, and meteorological phenomena.
Thales was considered the first Greek philosopher because he was the first to give a purely natural explanation
of the origin of the world, free from all mythological ingredients.
He proposed that all natural phenomena are different forms of one fundamental substance, water; he believed
evaporation and condensation to be the universal processes.
Anaximander of Miletus (mid-6th
century BC), a disciple of Thales, maintained that the first principle
from which all things evolve is an intangible, invisible, infinite substance that he called apeiron, or 'the
His notion of the boundless anticipated the modern notion of an unbounded universe. Apeiron, he maintained, is
eternal and indestructible.
Out of its ceaseless motion the more familiar substances—such as warmth, cold, earth, air, and fire—
continuously evolve, generating in turn the various objects and organisms that make up the recognizable world.
These forms in turn change and merge into one another according to the rule of justice, that is, balance and
Anaximenes of Miletus (late 6th
century BC) returned to Thales' assumption that the primary substance
is something familiar and material, but he claimed it to be air rather than water.
He believed that the changes things undergo could be explained in terms of rarefaction and condensation of air.
Anaximenes was the first philosopher to explain qualitative differences in terms of quantitative differences, a
method fundamental to physical science.
Heraclitus of Ephesus (c. 540-480 BC), continuing the search for a primary substance, claimed it to be
fire. He noticed that heat produces changes in matter, thus anticipating the modern theory of energy.
He believed that the entire world is in a constant state of change or flux and that most objects and substances are
produced by a union of opposite principles.
Heraclitus' theory of flux may be summarized as follows:
• The ongoing division of unified things into a multiplicity of opposing phenomena is 'the way
downwards' and is the consequence of war and strife.
• Harmony and peace lead back to 'the way upwards' and unity.
• Nature is constantly dividing and uniting herself so that the multiplicity of opposites does not
destroy the unity of the whole.
• The existence of these opposites depends only on the difference of the two opposing motions,
that of 'the way upwards' from that of 'the way downwards'.
• All things, therefore, are at once identical and not identical.
• The principle of the universe is becoming which implies that everything is and, at the same time,
is not, so far as the same relation is concerned.
• The way up and the way down are one and the same.
Heraclitus regarded the soul as a mixture of fire and water.
He maintained that stability is an illusion and that only change and the law of change, or logos, are real.
According to Heraclitus, "You cannot step twice into the same river."
His logos doctrine identified the laws of nature with a divine mind and later developed into the pantheistic
theology of Stoicism.
The Pythagorean School
Pythagoras (c. 580-500 BC) founded at Crotona, in southern Italy, a school of philosophy that was more
religious and mystical than the Ionian school.
It was Pythagoras who coined the term philosophia, Greek for 'love of wisdom'.
His ideas fused the ancient mythological view of the world with the developing interest in scientific
The system of philosophy that became known as Pythagoreanism combined ethical, supernatural, and
mathematical beliefs into a spiritualistic view of life.
The Pythagoreans believed that the soul is a prisoner of the body; that it is released from the body at death, and
reincarnated in a higher or lower form of life, depending on the degree of virtue achieved.
The highest purpose of humans should be to purify their souls by cultivating intellectual virtues, refraining from
sensual pleasures, and practicing various religious rituals.
The Pythagoreans, having discovered the mathematical laws of musical pitch, inferred that planetary motions
produce a 'music of the spheres'.
They identified science with mathematics, maintaining that all things are made up of numbers and geometrical
The Eleatic School
Xenophanes of Colophon (c. 560-478 BC), from the Phoenician colony of Elea in southern Italy, was
the father of pantheism and doctrine of the One.
He founded the Eleatic school of philosophical concepts which were later broadened and systematized by his
Xenophanes satirized the polytheistic beliefs of earlier Greek poets and ridiculed their deities as gods created in
the image of the mortals who worshiped them.
He rejected polytheistic anthropomorphism and promoted instead belief in a single nonhuman deity underlying
and unifying all worldly phenomena.
He declared God to be the eternal unity, permeating the universe, and governing it by his thought.
Parmenides (c. 515-450 BC), a disciple of Xenophanes, founded a school of philosophy at Elea, a
Greek colony on the Italian peninsula.
According to Parmenides the appearance of movement and the existence of separate objects in the world are
mere illusions; they only seem to exist.
He maintained that the universe, or the state of being, is an indivisible and unchanging entity and that all
reference to change or diversity is self-contradictory.
Nothing, he claimed, can be truly asserted except that "Being is."
The beliefs of Pythagoras and Parmenides formed the basis of the idealism that was to characterize later Greek
The Pluralists developed a philosophy which replaced the Ionian assumption of a single primary substance with
a plurality of such substances: pluralism.
Empedocles (c. 490-430 BC) maintained that all things are composed of four irreducible elements: air,
water, earth, and fire.
He maintained that these elements are alternately combined and separated by two opposing forces, love and
strife, to produce all known substances. By that process the world evolves from chaos to form and back to chaos
again, in an eternal cycle.
Empedocles regarded the eternal cycle as the proper object of religious worship and criticized the popular belief
in personal deities.
Anaxagoras (c. 500-428 BC) suggested that all things are composed of imperishable primary elements,
or very small particles, which exist in infinite variety.
He also maintained the existence of an ordering principle, a divine reason or nous, as ordering these primary
To explain the way in which these particles combine to form the objects that constitute the familiar world,
Anaxagoras developed a theory of cosmic evolution.
He maintained that the active principle of this evolutionary process is a world mind that separates and combines
He epitomized the philosophy of the Ionian school by suggesting a nonphysical governing principle and a
materialistic basis of existence.
His concept of elemental particles led to the development of an atomic theory of matter.
Atomism—a theory which proposed that all matter is composed of tiny, indivisible particles differing only in
simple physical properties.
century BC) and his more famous associate Democritus are generally credited with the first
systematic formulation of an atomic theory of matter.
Atoms were characterized as small primary bodies infinite in number, indivisible and imperishable,
qualitatively similar, but distinguished by their size, shape, and weight.
It was believed that atoms, falling eternally through the infinite void, collided and united, thus generating
objects which differ in accordance with the variety of the atoms which compose them.
Democritus (c. 460-370 BC) presented the first comprehensive statement of deterministic materialism, in
which all aspects of existence are claimed to be rigidly determined by physical (natural) laws.
He believed that the various forms of matter were caused by differences in the shape, size, position, and
arrangement of component atoms.
Even the sensory qualities of things such as warmth, cold, taste, and odor were reduced to the quantitative
differences among combinations of atoms.
The higher forms of existence, such as plant and animal life and even human thought, were explained by
Democritus in these purely physical terms.
He applied his theory to psychology, physiology, theory of knowledge, ethics, and politics.
Sophists, a group of traveling teachers famous throughout Greece toward the end of the 5th
century BC, played
an important role in developing the Greek city-states from agrarian monarchies into commercial democracies.
Specializing in rhetoric, the Sophists were more professional educators than philosophers.
As Greek industry and commerce expanded, a class of newly rich, economically powerful merchants began to
wield political power. Lacking the education of the aristocrats, they sought to prepare themselves for politics
and commerce by paying the Sophists for instruction in public speaking, legal argument, and general culture.
Although the best of the Sophists made valuable contributions to Greek thought, the group as a whole acquired
a reputation for deceit, insincerity, and demagoguery. Thus the word sophistry has come to signify these moral
Protagoras (c. 490-420 BC), a leading Sophist, is famous for the maxim "Man is the measure of all
Sophists held that individuals have the right to judge all matters for themselves. They denied the existence of
any objective knowledge.
They doubted that humanity would ever be able to reach objective truth through reason.
Gorgias (c. 483-376 BC), was another important Sophist whose philosophy is described as nihilistic and
whose work represented the sophistical love of paradox.
His position may be summed up in three propositions: (a) Nothing exists; (b) If anything existed, it could not be
known; (c) If anything did exit and could be known, it could not be communicated.
Sophistic thought identified knowledge with sense-perception and ignored the rational element. Since sense-
impressions differ in different people the object as it is in itself cannot be known.
Socrates (c. 470-399 BC) left no writings as records of his thought, but his teachings were preserved for
later generations in the dialogues of Plato.
Socrates’ contribution to philosophy was essentially ethical in character. Concepts such as justice, love, virtue,
and self-knowledge were the basis of his teachings.
He believed that all vice was the result of ignorance, and that knowledge was virtue.
Socrates taught that every person has full knowledge of ultimate truth contained within the soul and needs only
to be spurred to conscious reflection in order to become aware of it.
He believed that knowledge is innate, rather than learned from experience; that the philosopher's task was to
provoke people into thinking for themselves, rather than to teach them anything they did not already know.
One of the ideas that got Socrates in trouble was that he thought he was wiser than many of the people in power.
Like most of Socrates’ ideas, this is not what it seems in appearance. Socrates believed that he was wise
because he knew nothing and admitted it, while others thought they were wise but really were not. In other
words, anyone who admits to not being wise is really wise because no human can really attain complete
wisdom. One of Socrates friends had asked the oracle of Delphi if any were wiser than Socrates. The oracle said
“no” which greatly surprised Socrates. So Socrates examined famous politicians, artists, and poets to prove the
oracle wrong. After examining them and getting his victims into tight spots Socrates surmised that their wisdom
was illusionary and the oracle was right.
His contribution to the history of thought was not a systematic doctrine but a method of thinking and a way of
life. He stressed the need for analytical examination of one's beliefs; for clear definitions of basic concepts; for a
rational and critical approach to ethical problems.
Socrates employed two forms of philosophical inquiry, induction and definition, of which he is considered the
inventor. He considered dialectic as the highest method of the speculative thought.
He considered the soul not in mystical terms but as a combination of an individual's intelligence and character.
Through the writings of Plato and Aristotle, Socrates profoundly affected the entire subsequent course of
Western speculative thought.
Plato (c. 428-348 BC) was a more systematic and positive thinker than Socrates, but his writings,
particularly the earlier dialogues, can be regarded as a continuation and elaboration of Socratic insights.
The school founded by Plato was called the Academy.
Like Socrates, Plato regarded ethics as the highest branch of knowledge; he stressed the intellectual basis of
virtue and identified virtue with wisdom.
Plato also explored the fundamental problems of natural science, political theory, metaphysics, theology, and
theory of knowledge; he developed ideas that became permanent elements in Western thought.
The basis of Plato's philosophy is his theory of Ideas, or doctrine of Forms.
The theory of Ideas—expressed in many of his dialogues, particularly the Republic and the Parmenides—
divides existence into two realms:
• rational realm of perfect, eternal, and invisible Ideas, or Forms
• empirical realm of concrete, familiar objects know through sense experience
Trees, stones, human bodies, and other objects that can be known through the senses are for Plato unreal,
shadowy, and imperfect copies of the Ideas.
Plato’s high standard of knowledge required that all genuine objects of knowledge be described without
contradiction. Because all objects perceived by the senses undergo change, an assertion made about such
objects at one time will not be true at a later time.
Because that which is fully real must, for Plato, be fixed, permanent, and unchanging, he identified the real with
the ideal realm of being as opposed to the physical world of becoming.
According to Plato, sense objects are not completely real. Beliefs derived from experience of such objects are
therefore vague and unreliable, whereas the principles of mathematics and philosophy, discovered by inner,
rationalistic meditation on the Ideas, constitute the only knowledge worthy of the name.
One consequence of this view was Plato's rejection of empiricism, the claim that knowledge is derived from
sense experience. He thought that propositions derived from sense experience have, at most, a degree of
probability; they are not certain.
In the Republic, Plato described humanity as imprisoned in a cave and mistaking shadows on the wall for
reality; he regarded the philosopher as the person who penetrates the world outside the cave of ignorance and
achieves a vision of the true reality, the realm of Ideas.
Plato's theory of Ideas and his rationalistic view of knowledge formed the foundation for his ethical and social
idealism. The realm of eternal Ideas provides the standards or ideals according to which all objects and actions
should be judged.
The philosophical person, who refrains from sensual pleasures and searches instead for knowledge of abstract
principles, finds in these ideals the modes for personal behavior and social institutions.
For Plato, personal virtue consists of harmony among the faculties of the soul. Social justice consists of
harmony among the classes of society.
The ideal state of a sound mind in a sound body requires that the intellect control the desires and passions, as
the ideal state of society requires that the wisest individuals rule the pleasure-seeking masses.
According to Plato, art that expresses moral values is the best art. In his rather conservative social program,
Plato supported the censorship of art, regarding art as an instrument for the moral education of youth.
Plato's concept of the absolute Idea of the Good (which is the highest Form and includes all others) has been a
main source of pantheistic and mystical religious doctrines in Western culture.
Truth, beauty, and justice coincide in the Idea of the Good; this supreme Idea, or Form, represents Plato's
movement in the direction of an ultimate principle of explanation.
Ultimately, the theory of Forms was intended to explain how one comes to know and also how things have
come to be as they are. In philosophical language, Plato's theory of Forms is both an epistemological (theory of
knowledge) and an ontological (theory of being) thesis.
Plato’s tripartite theory of the soul
Plato theory of the soul is the origin of his theory of the state. In it he claims that the only happy person is the
just person, or the person who is ruled by Reason.
According to Plato, the soul consists of three basic energies which animate human beings: Reason, Emotion,
and Appetite. Reason is given the greatest value, while Emotion and especially Appetite are regarded as the
"lower passions". The soul that is ordered is governed by Reason, and therefore keeps one's emotions and one's
appetites under control. The lower passions *must* submit to the dictates of Reason.
Plato's theory of the soul can be found in his major work, *The Republic*, where it is a response to the
challenge of the Sophists as to why one ought to live morally. The Sophists in Plato's time were men who used
philosophy for profit, inventing moral loopholes to get people out of obligations, or to excuse what would
otherwise be considered immoral behavior. The skeptics ask why one ought to be moral when morality is
apparently a social device for maintaining order. But if there are no consequences to "immoral behavior," then
there is no motivational pressure for morality.
Plato answers by claiming that morality is a necessary cause of happiness, that one's happiness is correlary to
one's moral behavior. Therefore, an immoral person would be motivated to be moral if he wants to be happy.
The happy person, according to Plato, is the just person, a claim that he posits in two ways:
The response of the skeptics is to claim that daily reality contradicts Plato, and that contrary to number one,
tyrants, motivated by unjust principles, may be found to be happy. Moroever, they argue that contrary to
number 2, saints and renunciates are known to suffer, rather than to be happy. This is where Plato's theory of the
Soul is established. He argues to the contrary that the three basic energies of the soul must be ordered in order
for a person to be happy. The Emotions (reactions like anger or fear) and the Appetites (needs for food, sex,
money, etc), must be ruled by Reason (thinking, persuasion, arguement) in order for a person to be truly happy.
When the lower passions are ruled by Reason, a person is also therby just.
In response to the skeptics, Plato argues that the tyrant is not therefore truly happy, and that this can be seen in
his behavior. Ruled by lower passions, tyrants are known to displace Reason with Emotion, such as the fear of
being assassinated, the inability to trust others; or, he will displace Reason with Appetite, such as the unsatiable
greed for riches or power. In the end, such a person will be pulled apart by his lower passions, and cannot
possibly find happiness with a disordered soul. Plato brings up the ancient figure of the tragic hero in order to
illustrate this. Moreover, Plato argues, the suffering saint is happy amid his suffering because he is ruled by
reason, and his soul is ordered. Happiness thus springs from inward qualities in the soul, according to Plato, and
is not contingent upon external circumstances. When the lower passions are ordered by Reason, there is
"psychic harmony," a quality of soul that is not vulnerable to a fatal blow from an external source. A person can
therefore suffer externally, and remain happy because there is harmony internally, in his soul.
The psychic harmony of the soul, according to Plato, expresses itself in four cardinal virtues, which are each
related to the three basic energies of the soul. In relation to Reason, the happy or just person possesses Wisdom
(or prudence). In relation to Emotion, the just person has the virtue of Courage. In relation to Appetite, the just
person owns the virtue of Temperance, which is the control of natural desires. Flowing outward from this
psychic harmony is the fourth cardinal virtue, Justice. Wisdom, Courage and Temperance are directly related to
one's own self-control; Justice flows outward from this harmony, and is directed towards other people through
acts of charity and kindness.
Plato was prepared to say that the truly just person, whose soul is ordered, is beyond tragedy, and cannot be
harmed. Such a person is leading a meangingful life, as against the immoral person. Moreover, Plato extended
his theory of the Soul to encapsulate the perfect government, the Republic, led by "philosopher kings" who are
just, governed by Reason.
Aristotle (384-322 BC) was the most illustrious pupil of Plato and ranks with his teacher among the
most profound and influential thinkers of the Western world.
Aristotle was for some time the tutor of Alexander the Great .
He later returned to Athens to found his own school called the Lyceum; like Plato's Academy, the Lyceum
remained for centuries one of the great centers of learning in Greece.
In his lecture notes Aristotle defined the basic concepts and principles of many of the theoretical sciences, such
as logic, biology, physics, and psychology.
Philosophy to him meant science and recognition of the purpose in all things. Unlike Plato, Aristotle preferred
to establish the ultimate basis of things inductively—by a posteriori conclusions—from particular facts to a
universal conclusion, or from effects to causes.
In founding the science of logic Aristotle developed the theory of deductive inference, represented by the
syllogism, a deductive argument having two premises and a conclusion.
In his metaphysical theory, Aristotle criticized Plato's separation of form from matter and maintained that the
Forms are contained within the concrete objects that exemplify them.
For Aristotle form and matter were inherent in all things, and inseparable.
He believed that everything real is a combination of potentiality and actuality, a combination of that which a
thing may become, but is not yet, and that which it already is.
The one exception: human and divine intellect are pure forms. Aristotle referred to the prime mover, or first
cause, as pure intellect; perfect in unity and immutable.
Nature, for Aristotle, is an organic system of things whose common forms make it possible to arrange them into
classes comprising species and genera.
Each species has a form, purpose, and mode of development in terms of which it can be defined; the aim of
theoretical science is to define the essential forms, purposes, and modes of development of all species and to
arrange them in their natural order.
Aristotle’s hierarchical classification of nature was adopted by many Christian, Jewish, and Muslim theologians
in the Middle Ages as a view of nature consistent with their religious beliefs.
One of the most distinctive of Aristotle's philosophic contributions was his teleology, or theories of causality.
Each thing or event has four causes, or aition (responsible or explanatory factors):
• material cause - the matter out of which a thing is made
• efficient cause - the source of motion, generation, or change
• formal cause - which is the species, kind, or type
• final cause - the goal or full development of an object
Aristotle taught that something can be better understood when its causes can be stated in specific terms rather
than in general terms; that his causal pattern was the ideal key for organizing knowledge.
Aristotle's political and ethical philosophy developed out of a critical examination of Platonic principles. The
standards of personal and social behavior, according to Aristotle, must be found in the scientific study of the
natural tendencies of individuals and societies rather than in a heavenly realm of pure forms.
Aristotle regarded ethical rules as practical guides to a happy and well-rounded life. His emphasis on happiness,
as the active fulfillment of natural capacities, expressed the attitude toward life held by cultivated Greeks of his
In his theory of knowledge, Aristotle rejected the Platonic doctrine that knowledge is innate and insisted that it
can be acquired only by generalization from experience.
Aristotle clearly stated the relationship between human insight and the senses in what has become a slogan of
empiricism, that knowledge is grounded in sense experience. "There is nothing in the intellect that was not first
in the senses."
He interpreted art as a means of pleasure and intellectual enlightenment rather than an instrument of moral
Aristotle's ethics is strongly practical. Aristotle said that virtues are a point of moderation between two opposite
vices. For instance, the virtue courage lies between the two vices of cowardice and recklessness. Recklessness is
too much confidence and not enough fear, cowardice is too much fear and not enough confidence, courage is
just the right amount of both.
This can be expanded to most virtues and vices. Some other means that Aristotle laid out were temperance (or
self-control), which lies between self-indulgence and a lack of sensitivity to your own needs, and modesty
which is between bashfulness and vanity.
I. Based on the handout provided answer the following questions
1. Enumerate the Pre-Socratic thinkers with their respective contributions.
2. What was the main concern of pre-Socratic thinkers?
3. How did Greek philosophy develop?
4. Who are the sophists?
5. Explain man is the measure of all things.
6. Do you agree with Gorgias argument? Why?
7. In line with Socrates philosophy, explain the maxim, “Wisest is he who knows that he does not know.”
8. Describe the two realities mentioned by Plato.
9. How can you relate Plato’s philosophy in our contemporary society?
10. Based on Plato’s theory of the tripartite human spirit, who is a “Happy person?”
11. How did Aristotle describe reality?
12. Explain and give concrete examples of Aristotle’s Golden Mean.