Who are Socratic Philosophers?

The Socratic or Classical period of the Ancient era of philosophy denotes the Greek contemporaries and near contemporaries of the influential philosopher Socrates.

Major Philosophers of the time include:

 Socrates (464 – 399 B.C.) Greek
Plato (c. 428 – 348 B.C.) Greek
Diogenes of Sinope (c. 412 – 323 B.C.) Greek
Aristotle (384 – 322 B.C.) Greek

Socrates developed a system of critical reasoning in order to work out how to live properly and to tell the difference between right and wrong. He and his followers, Plato and Aristotle maintained an unwavering commitment to the truth, and between them they organized and systematized most of the problems of philosophy.

Important philosophical movements of the period include Cynicism, Hedonism, Platonism and Aristotelianism.


Diogenes of Sinope (c. 412 – 323 B.C.)


diogenesDiogenes of Sinope (aka Diogenes the Cynic) (c. 412 – 323 B.C.) was a Greek philosopher of the Socratic (or Classical) period. He was one of the founders (and the archtypical practitioner) of the ancient Greek philosophical school of Cynicism.

He lived as a beggar in the streets of Athens and made a virtue of extreme poverty. He taught contempt for all human achievements, social values and institutions. But his sharp wit and stinging satire was very effective in highlighting the decadence, irrationality and double standards of Athens society.


Diogenes (pronounced die-O-jen-ees) was born in about 412 B.C. (or 404 B.C., according to some sources) in Sinope (on the Black Sea coast of modern-day Turkey), the son of Tresius, a rich money-changer. It is likely that he was exiled from Sinope for adulterating the coins his father minted with base metals, and made his way to Athens with a slave named Manes, who abandoned him shortly thereafter. He lived as a beggar in the streets of Athens, living semi-naked in a tub by the temple of Cybele, making a virtue of his extreme poverty.

He was attracted by the Ascetic teaching of Antisthenes (c. 445 – 365 B.C.), a student of Socrates. Diogenes became Antisthenes’ pupil, despite the brutality with which he was received, and rapidly surpassed his master both in reputation and in the austerity of his life. He avoided all earthly pleasures, and openly disdained what he saw as the folly, pretense, vanity, social climbing, self-deception and artificiality of much human conduct.

Most of what we know of his life has come to us in the form of anecdotes, especially from the “Lives and Opinions of Eminent Philosophers” of the 3rd Century historian of the ancient Greek philosophers, Diogenes Laërtius. For instance, he destroyed his only possession, a single wooden bowl, on seeing a peasant boy drink from the hollow of his hands. He used to stroll about in full daylight with a lamp, because he claimed to be looking for an honest man. He lavishly praised the virtues of dogs (which eat anything, make no fuss about where to sleep, perform natural bodily functions in public without unease, and know instinctively who is friendand who is foe), all of which makes them superior to humans in his view. At one time, he poured scorn on Plato‘s characterization of man as a featherless biped, by bringing a plucked chicken into the lecture room. He is also credited with the first known use of the word “cosmopolitan”, claiming to be a “cosmopolites” (“citizen of the world”).

He showed his rejection of “normal” ideas about human decency by eating in the street,  urinating on those who insulted him, defecating in the theatre, and pointing at people with his middle finger. He was a self-appointed public scold whose mission was to demonstrate to the ancient Greeks that civilization is regressive.

As the stories have it, Diogenes was captured by pirates and sold as a slave in Crete to a Corinthian named Xeniades, who was impressed with his wit and vision and employed him as tutor to his two sons. He lived in Corinth for the rest of his life, which he devoted to preaching the doctrines of virtuous self-control. At one point, he supposedly met Alexander the Great in Corinth, and impressed the great leader with his ingenuity and wisdom, causing Alexander to remark, “If I were not Alexander, then I should wish to be Diogenes”.

He died in 323 B.C. at Corinth, alleged variously to have held his breath, to have become ill from eating raw octopus, or to have suffered an infected dog bite. He left instructions to be thrown outside the city wall on his death, so wild animals could feast on his body. The Corinthians erected to his memory a pillar on which rested a dog of Parian marble.


No writings of Diogenes have survived even though he is reported to have authored several books. All we have is a number of anecdotes concerning his life and sayings attributed to him in a number of scattered classical sources, none of them definitive. (For a comprehensive list of some of Diogenes’ wittiest sayings, go to the Diogenes the Dog website.)

Along with Antisthenes (c. 445 – 365 B.C.) and Crates of Thebes (c. 365 – 285 B.C.), Diogenes is considered one of the founders of the school of Cynicism. The doctrine of Cynicism holds that the purpose of life is to live a life of Virtue in agreement with Nature (which calls for only the bare necessities required for existence). This involves rejecting all conventional desires for health, wealth, power and fame, and living a life free from all possessions and property.

Although Antisthenes preached a life of poverty, and Crates even gave away a large fortune to live a life of poverty in Athens, Diogenes took Cynicism to its logical extremes and dominates the story of Cynicism like no other figure. He dedicated his life to self-sufficiency (“autarkeia”), austerity (“askesis”) and shamelessness(“anaideia”), and was famed for his biting satire and wit. His rather shocking lifestyle and habits were never gratuitous, but were used to subtly illustrate his contempt for human achievements, social values and institutions, and to point out the irrationality of accepted conventions.

Like Socrates, Diogenes believed that he could function as doctor to men’s soulsand improve them morally, while at the same time holding contempt for their obtuseness. Plato once described him as “a Socrates gone mad”. Diogenes, in return, was a particularly harsh critic of Plato and his metaphysical pursuits. In his anti-Platonic insistence that reason should replace authority in guiding human affairs, and his vision of a free community without government, Diogenes can also be considered a proto-Anarchist.

As a philosopher, Diogenes was taken surprising seriously, despite his shock tactics. He apparently proved to the satisfaction of the Stoics who came after him that happiness has nothing whatever to do with a person’s material circumstances, and they claimed him to be a “sophos” or wise man. An exile and an outcast, a man with no social identity, Diogenes certainly made a mark on his contemporaries, and his story continues to fascinate students of human nature.

Aristotle (384 – 322 B.C.)


AristotleAristotle (384 – 322 B.C.) was an important Greek philosopher from the Classical period, mainly based in Athens. He is one of the most important founding figures in Western Philosophy, and the first to create a comprehensive system of philosophy, encompassing Ethics, Aesthetics, Politics, Metaphysics, Logic and science.

His own school of philosophy, known as Aristotelianism or the Peripatetic School, influenced almost all later philosophical thinking, particularly the Medieval movements such as Scholasticism, Averroism and Avicennism.


Aristotle was born to an aristocratic family in Stageira on the Chalcidice Peninsula of Macedonia (a region of northern Greece) in 384 B.C. His father, Nicomachus, was the personal physician to King Amyntas of Macedon, and Aristotle was trained and educated as a member of the aristocracy. Aristotle’s mother, Phaestis, came from Chalcis on the island of Euboea, and her family owned property there.

When he was just a boy of the age of 10, Aristotle’s father died (which meant that Aristotle could not now follow in his father’s profession of doctor) and his mother seems also to have died young, so he was taken under the care of a man named Proxenus. At the age of 18, he moved to Athens to compete his education at Plato‘s famous Academy, where he remained for nearly twenty years (first as a star student and then as a teacher and a philosophical force to be reckoned with in his own right) until after Plato‘s death in 347 B.C.

Plato‘s nephew Speusippus (407 – 339 B.C.) was chosen to succeed him as head of the Academy (partly because Aristotle’s ideas had diverged too far from Plato’s) and Aristotle left the Academy. He travelled for some time in Asia Minor with Xenocrates (396 – 314 B.C.) and Theophrastus (371 – 287 B.C.). While staying at the court of Hermias of Atarneus, an ex-student of Plato, he met and marriedHermias’ daughter, Pythias, and together they had a daughter also called Pythias. After Hermias’ death, Aristotle was invited by Philip of Macedon to tutor to the young Alexander the Great, which he did for several years before returning to Athens. His wife Pythias died soon after, and Aristotle became involved with Herpyllis from his home town of Stageira, and they had a son named after Aristotle’s father, Nicomachus.

In 335 B.C., Aristotle established his own school just outside the walls of Athens, known as the Lyceum, in competition with Plato‘s long-established Academy, and he conducted courses at the school for the next thirteen years. His immediate followers were known as the Peripatetics (meaning “itinerant” or “walking about”, for their habit of walking the covered walkways of the Lyceum). The Lyceum had a broader curriculum than the Academy, and a stronger emphasis on natural philosophy. Artistotle’s most famous students were Theophrastus (371 – 287 B.C.), who followed Artistotle as head of the Lyceum, and Strato of Lampsacus (225 – 269 B.C.) who succeeded him.

It is during this period in Athens that Aristotle is believed to have composed many of his major works, although only fragments of his many dialogues have survived, and those mainly in treatise form, generally thought to be lecture aids for his students. His most important treatises include the six books of the “Organon”“Physics”“Metaphysics”“Nicomachean Ethics”“Politics”“De Anima”(“On the Soul”), “Rhetoric” and “Poetics”.

On the death of Alexander the Great in 323 B.C.anti-Macedonian sentiment in Athens flared once again, and Aristotle fled the city to his mother’s family estate in Chalcis, explaining “I will not allow the Athenians to sin twice against philosophy” (a reference to the trial and execution of Socrates). He soon died of natural causes there, at the age of 62, and was eventually buried next to his wife.


Aristotle wrote extensively, but only about one-fifth of his works have survived (although even that fills about 12 volumes, and touches on the whole range of what was available knowledge at his time).

Aristotle himself divided his writings into the “exoteric” (intended for publication) and the “esoteric” (compiled from his lecture notes, and intended for the narrower audience of his students and other philosophers familiar with the jargon and issues typical of the Platonic and Aristotelian schools). Unfortunately, none of the exoteric works he produced for publication (which were praised throughout antiquity for their great beauty of style) seem to have survived, not even fragments, and so we have no examples of his literary art, as we have of Plato’s writing.

Even some of his esoteric works may well have been altered or “repaired” after the original manuscripts were left to languish in a cellar in Asia Minor before being rediscovered by some Roman scholars of dubious reputation in the 1st Century B.C.(although this account of their history is disputed). It was not until the Scholasticism and Averroism of the Middle Ages (when he was known simply as “The Philosopher”) that Latin translations became widely available again, stimulating a revival of Aristotelianism in Europe, and ultimately revitalizing European thought through Muslim influence in Spain to fan the embers of the Renaissance.

What we today call Aristotelian Logic, Aristotle himself would have labelled “analytics”, and he used the term “logic” to mean dialectics (the exchange of arguments and counter-arguments in search of a synthesis or resolution). Aristotle’s ground-breaking work on Logic were collected together into the six books of the “Organon” in the early 1st Century A.D., and it constitutes the earliest formal study of Logic. His conception of Logic has had an unparalleled influence on the history of Western thought, and was the dominant form of Logic until 19th Century advances in mathematical logic and predicate logic. As recently as the late 18th Century, no less a philosopher than Immanuel Kant claimed that Aristotle had said all there was to say on the subject of Logic.

His aim was to develop a universal method of reasoning by means of which it would be possible to learn everything there is to know about reality. Aristotle defined logic as “new and necessary reasoning”, “new” because it allows us to learn what we do not know, and “necessary” because its conclusions are inescapable.

At the heart of Aristotelian Logic is the syllogism (or deductive logic or term logic), which he developed in his “Prior Analytics”, the third book of the “Organon”. In a syllogism, one proposition (the conclusion) is inferred from two others (the premises), each of which has one term in common with the conclusion. A proposition in this context is an assertion which consists of two terms (the subject and the predicate), and which is capable of truth or falsity. He enumerated ten categories to describe all the possible kinds of thing which can be the subject or the predicate of a proposition: Substance, Quantity, Quality, Relation, Place, Time, Position, State, Action and Affection. In other books of the “Organon”, Aristotle considers issues in constructing valid argumentsprobable inferences(as opposed to certain ones) and logical fallacies, among other topics.

Aristotle also popularized the use of axioms (self-evident principles requiring no proof), claiming that nothing can be deduced if nothing is assumed, as well as the hugely important Principle of Non-Contradiction, which held that a particular attribute can not both apply and not apply to the same subject at the same time (e.g. 2 + 2 = 4 and 2 + 2 = 5 cannot both apply). The use of axioms was important in other areas of Aristotle’s philosophy, not least in his Metaphysics.

Aristotle’s Metaphysics (the very word “metaphysics” dates back to Aristotle, originally having the rather mundane meaning of those books which come after his work on physics) revolves around the concept of substance, which is a combination of both matter (the substratum or “stuff” of which a thing is composed) and form (the actual thing itself). Things have both potentiality (what it is capable of doing or becoming, if not prevented by something else) and actuality (the fulfillment or the end of the potentiality). Thus, the matter of a thing is its potentiality, and the form is its actuality. Essence is what provides the shape or form or purpose to matter, and the movement from formless stuff to complete being results from four causesmaterial cause (what something is made of, the coming together of it parts), efficient cause(the motion or energy that changes matter), formal cause (a thing’s shape, form, essence or definition) and final cause (a thing’s reason or purpose or the intention behind it).

Aristotle tried to pin down what it is that persists in a thing that gives it its continuity as a single thing, even while its properties and attributes change (e.g. a leaf starts as a bud, grows and turns green, and then withers and dies, but it remains throughout incontestably the same leaf). He also asked what are the fundamental properties of a thing which give it its identity as a particular thing, and without which it would cease to be the same thing. He saw these two questions as inextricably entwined.

Aristotle broke irrevocably with his teacher Plato and the Platonists over the problem of universals and his conception of hylomorphism (the idea that substances are forms inhering in matter). Aristotle’s conception of hylomorphism differed from that of Plato in that he held that Form and Matter are inseparable, and that matter and form do not exist apart from each other, but only together. Just as the word hylomorphism itself is composed of the Greek hyle (matter or stuff) and morphe (form or structure), Aristotle’s classic answer to the question of what reality really consists of was that reality = stuff + structure. Stuff without structure was mere chaos, while structure without stuff was no more than the ghost of being.

Plato believed that ideal Forms exist, separate and apart from particular things, for which they are prototypes or exemplars. Aristotle, on the other hand, held that universals exist only where they are instantiated, and then only “in things”, never apart from them (i.e. the universals are “inside” the particulars). Where Plato had located ultimate reality in ideas or eternal Forms, knowable only through reflectionand reason, Aristotle saw ultimate reality in physical objects, knowable through experience. Indeeed, he considered it meaningless to discuss something which has not been encountered or experienced in real life. For Plato, the philosophic method means the descent from a knowledge of universal Forms (or ideas) to a contemplation of particular imitations of these, while for Aristotle the philosophic method implies the ascent from the study of particular phenomena to the knowledge of essences.

Aristotle made some highly influential constributions to the field of Ethics. He considered Ethics to be a practical science (i.e. mastered by doing rather than merely reasoning) but also a general, rather than a certain, knowledge. Unlike some other moral philosophers before him, Aristotle started by posing the very general question of what it actually means to lead a good human life. He was also very aware that morality is a complex concept and so cannot be measured in any one simple way (in the way that Utilitarianism, for example, measures morality on a simple scale of happiness created). Also (again, unlike some other philosophers such as the Stoics and the Epicureans, for example), Aristotle firmly believed that we are not self-contained moral entities and that we cannot control our own moral environment.

His several treatises on Ethics, most notably the “Nichomachean Ethics”, outline what is commonly called Virtue Ethics or Eudaimonism. He argued that Man must have a specific or proper function, which is uncommon to anything else, and which is an activity of the soul. The best activity of the soul is eudaimonia (happiness or joy or the good life), which can be achieved by living a balanced life and avoiding excess by pursuing a golden mean in everything between the two vices of excess and deficiency.

In Politics, Aristotle was the first to conceive of an organic city or natural community, and indeed conceived of Politics as a whole as organic, as a collection of parts that cannot exist without the others. For Aristotle, a city (the political unit with which he was familiar, the concept of the state as we know it still being then unknown) was a political partnership which existed for the sake of “noble actions”, not merely for the sake of living together, nor as a social contract to avoid injustice or economic instability. In comparison with some other political commentators of the time (such as Plato), though, Aristotle’s had a rather narrow-minded view of just who should be allowed to be a citizen of such a city, and his attitude to women and foreigners in general was quite chauvinistic. His formula for political stability was a strong middle class in order to achieve the middle ground between tyranny and democracy. He may also have been the author of a model constitution of Athens, in which the abstract notion of constitutional government is applied to the concrete life of a particular society.

Aristotle’s philosophical endeavours encompassed virtually all facets of intellectual inquiry, including “natural philosophy”, the branch of philosophy examining the phenomena of the natural world (what would be regarded today as physicsbiology and other natural sciences). In fact, he spent much of his time performing original research in the natural sciences, in areas such as botany, zoology, physics, astronomy, chemistry, meteorology and several other sciences, and to a large extent Aristotle was responsible for establishing these sciences as individual fields of enquiry and study. He was endlessly fascinated with nature, and went a long way towards classifying the plants and animals of Greece through observation and anatomical dissection.

In Aristotle’s physics there are five elements, all of which naturally move towards their default natural place: fire (hot and dry), earth (cold and dry), air (hot and wet); water (cold and wet) and aether (the divine substance that makes up the stars and planets). In his treatise “Meteorology” (then a broader term than its use today), he discussed the nature of the earth and the oceans, including the hydrologic cycle and natural occurences like winds, earthquakes, thunder, lightning, rainbows, and meteors, comets and the Milky Way. His “De Anima” (“On the Soul”) is perhaps the first ever book on psychology. In it, he argued that the mind is essentially the purposeful functioning of the nervous system, and he described the struggle of the id and ego (desire and reason).

Unlike Plato, Aristotle took observation to be crucial, but (in the absence of concepts like mass, velocity, force and temperature, and given his insistence on deriving “laws of the universe” from simple observation and over-stretched reason, rather than strict scientific method, and his largely qualitative rather than quantitative approach) his scientific observations are a mixture of precocious accuracy and curious errors, and have long been deemed hopelessly inadequate. However, his project of a systematic investigation into natural phenomena in the living world arguably marks the birth of empirical science.

Aristotle was interested in more than a strictly scientific exploration of human nature, though, as testified by works like the “Poetics” and “Rhetoric”. Aristotle considered literature (e.g. epic poetry, tragedy, comedy), music and dance to be essentially imitative, although he considered such imitiation to be natural to mankind and one of mankind’s major advantages over animals.


Plato (c. 428 – 348 B.C.)


PlatoPlato (c. 428 – 348 B.C.) was a hugely important Greek philosopher and mathematician from the Socratic (or Classical) period.

He is perhaps the best known, most widely studied and most influential philosopher of all time. Together with his mentorSocrates, and his student, Aristotle, he provided the main opposition to the Materialist view of the world represented by Democritus and Epicurus, and he helped to lay the foundations of the whole of Western Philosophy.

Plato was the founder of the famous Academy in Athens, the first institution of higher learning in the western world. The philosophical school which he developed at the Academy was known as Platonism (and its later off-shoot, Neo-Platonism).


Plato was born in Athens (or possibly in Aegina, according to some sources) some time between 429 and 423 B.C. (most modern scholars use estimate of 428 or 427 B.C.) He was possibly originally named Aristocles after his grandfather, and only later dubbed “Plato” or “Platon” (meaning “broad”) on account of the breadth of his eloquence, or of his wide forehead, or possibly on account of his generally robust figure.

His father was Ariston (who may have traced his descent from Codrus, the last of the legendary kings of Athens); his mother was Perictione (who was descended from the famous Athenian lawmaker and poet Solon, and whose family also boasted prominent figures of the oligarchic regime of Athens known as the Thirty Tyrants). He had two brothers, Adeimantus and Glaucon, and a sister, Potone. Plato later introduced several of his distinguished relatives into his dialogues, indicating considerable family pride.

When Ariston died early in Plato’s childhood, his mother married her own uncle, Pyrilampes, who was also a friend of Pericles (the leader of the democratic faction in Athens), and who had served many times as an ambassador to the Persian court. Together, they had another son, Antiphon, who was therefore Plato’s half-brother.

Coming as he did from one of the wealthiest and most politically active families in Athens, Plato must have been instructed in grammarmusic and gymnastics by the most distinguished teachers of his time, and certainly his quickness of mind and modesty were widely praised. He had also attended courses of philosophy and was acquainted with Cratylus, a disciple of Heraclitus, before meeting Socrates. This life-changing event occurred when Plato was about twenty years old, and the intercourse between master and pupil probably lasted eight or ten years. As a youth he had loved to write poetry and tragedies, but burnt them all after he became a student of Socrates and turned to philosophy in earnest. It is plain that no influence on Plato was greater than that of Socrates.

Plato was in military service from 409 to 404 B.C. and, for a time, he imagined a life in public affairs for himself. He was even invited to join the administration of the regime of the Thirty Tyrants (through the connection with his uncle, Charmides, who was himself a member), but he was soon repelled by their violent acts and backed out. In 403 B.C.democracy was restored to Athens, and Plato had renewed hopes of entering politics again, although the excesses of Athenian political life in general persuaded him to hold back. The execution of Socrates in 399 B.C. had a profound effect on him, and he decided to have nothing further to do with politics in Athens.

After Socrates‘ death, he joined a group of Socratic disciples who had gathered in the Greek city of Megara under the leadership of Euclid of Megara, before leaving and travelling quite widely in ItalySicilyEgypt and Cyrene. During his time in Italy, he also studied with students of Pythagoras and came to appreciate the value of mathematics.

When he returned to Athens in about 385 or 387 B.C., Plato founded the Academy(or Akademia), one of the earliest and most famous organized schools in western civilization and the protoype for later universities, on a plot of land containing a sacred grove just outside the city walls of ancient Athens, which had once belonged to the Athenian hero Akademos. Plato had been bitterly disappointed with the standards displayed by those in public office, and his intention was to train young men in philosophy and the sciences in order to create better statesmen, as well as to continue the work of his former teacher, Socrates. Among Plato’s more noteworthy students at the Academy were Aristotle, Xenocrates (396 – 314 B.C.), Speusippus(407 – 339 B.C.) and Theophrastus (c. 371 – 287 B.C.).

Except for two more rather ill-advised and ill-fated trips to Syracuse in Sicily in 367 B.C. and 361 B.C. to tutor the young ruler Dionysius II, Plato presided over his Academy from 387 B.C. until his death in 347 B.C., aged about 80. He was supposedly buried in the school grounds, although his grave has never been discovered.

On Plato’s death, his nephew Speusippus succeeded him as head of the school (perhaps because his star pupil Aristotle’s ideas had by that time diverged too far from Plato’s). The school continued to operate for almost 900 years, until A.D. 529, when it was closed by the Byzantine Emperor Justinian I, who saw it as a threat to the propagation of Christianity.


Plato is perhaps the first philosopher whose complete works are still available to us. He wrote no systematic treatises giving his views, but rather he wrote a number (about 35, although the authenticity of at least some of these remains in doubt) of superb dialogues, written in the form of conversations, a form which permitted him to develop the Socratic method of question and answer. In his dialogues, Plato discussed every kind of philosophical idea, including Ethics (with discussion of the nature of virtue), Metaphysics (where topics include immortality, man, mind, and Realism), Political Philosophy (where topics such as censorship and the ideal state are discussed), Philosophy of Religion (considering topics such as Atheism, Dualism and Pantheism), Epistemology (where he looked at ideas such as a priori knowledge and Rationalism), the Philosophy of Mathematics and the Theory of Art(especially dance, music, poetry, architecture and drama).

We have no material evidence about exactly when Plato wrote each of his dialogues, nor the extent to which some might have been later revised or rewritten, nor even whether all or part of them were ever “published” or made widely available. In addition to the ideas they contained, though, his writings are also considered superb pieces of literature in their own right, in terms of the mastery of language, the power of indicating character, the sense of situation, and the keen eye for both tragic and comic aspects.

None of the dialogues contain Plato himself as a character, and so he does not actually declare that anything asserted in them are specifically his own views. The characters in the dialogues are generally historical, with Socrates usually as the protagonist (particularly in the early dialogues). It is generally thought that the views expressed by the character of Socrates in Plato’s dialogues were views that Socrates himself actually held, and the works had the effect of gradually rehabilitating Socrates‘s rather tarnished image among Athenians in the wake of his death. As time went on, though, the dialogues began to deal more with subjects that interested Plato himself, rather than merely providing a vehicle for the ideas of Socrates. It seems likely that Plato’s main intention in his dialogues was more to teach his students to think for themselves and to find their own answers to the big questions, rather than to blindly follow his own opinions (or those of Socrates).

Central to Plato’s Metaphysics is his theory of Platonic Realism, which inverts the common sense intuition about what is knowable and what is real. Confusingly, this is also known as Platonic Idealism, and indeed Idealism may be a better description. Plato believed that universals (those properties of an object which can exist in more than one place at the same time e.g. the quality of “redness”) do in fact exist and are real. However, they exist in a different way than ordinary physical objects exist, in a sort of ghostly mode of existence, unseen and unfelt, outside of space and time, but not at any spatial or temporal distance from people’s bodies (a type of Dualism).

Part and parcel of Plato’s Platonic Realism is his theory of Forms or Ideas, which refers to his belief that the material world as it seems to us is not the real world, but only a shadow or a poor copy of the real world. This is based on Plato’s concept (or Socrates’ through Plato) of hylomorphism, the idea that substances are forms inhering in matter. He held that substance is composed of matter and form, although not as any kind of a mixture or amalgam, but composed homogeneously together such that no matter can exist without form (or form without matter). Thus, pure matter and pure form can never be perceived, only comprehended abstractly by the intellect.

Forms, roughly speaking, are the pure and unchanging archetypes or abstract representations of universals and of all the things we see around us, and they are in fact the true basis of reality. These ideal Forms are instantiated by one or many different particulars, which are essentially material copies of the Forms, and make up the world we perceive around us. Plato was therefore one of the first Essentialists in that he believed that all things have essences or attributes that make an object or substance what it fundamentally is. According to Plato, true knowledge or intelligence is the ability to grasp the world of Forms with one’s mind, even though his evidence for the existence of Forms is intuitive only.

This idea was most famously captured and illustrated in Plato’s Allegory of the Cave, from his best-known work, “The Republic”. He represented man’s condition as being chained in the darkness of a cave, with only the false light of a fire behind him. He can perceive the outside world solely by watching the shadows on the wall in front of him, not realizing that this view of existence is limited, wrong or in any way lacking (after all, it is all he knows). Plato imagined what would occur if some of the chained men were suddenly released from this bondage and let out into the world, to encounter the divine light of the sun and perceive “true” reality. He described how some people would immediately be frightened and want to return to the familiar dark existence of the cave, while the more enlightened would look at the sun and finally see the world as it truly is. If they were then to return to the cave and try to explain what they had seen, they would be mocked mercilessly and called fanciful, even mad. In the allegory, Plato saw the outside world, which the cave’s inhabitants glimpsed only in a second-hand way, as the timeless realm of Forms, where genuine reality resides. The shadows on the wall represent the world we see around us, which we assume to be real, but which in fact is a mere imitation of the real thing.

Plato’s theory of Forms was essentially an attempt to solve the dichotomy between Parmenides’ view (that there is no real change or multiplicity in the world, and that reality is one) and that of Heraclitus (that motion and multiplicity are real, and that permanence is only apparent) by means of a metaphysical compromise. Plato himself, though, was well aware of the limitations of his theory, and in particular he later concocted the “Third Man Argument” against his own theory: if a Form and a particular are alike, then there must be another (third) thing by possession of which they are alike, leading to an infinite regression. In a later (rather unsatisfactory) version of the theory, he tried to circumvent this objection by positing that particulars do not actually exist as such: rather, they “mime” the Forms, merely appearing to be particulars.

In the “Timaeus”, Plato gave his account of the natural sciences (physics, astronomy, chemistry and biology) and the creation of the universe by the Demiurge. Unlike the creation by the God of medieval theologians, Plato’s Demiurge did not create out of nothing, but rather ordered the cosmos out of already-existing chaotic elemental matter, imitating the eternal Forms. Plato took the four elements (fire, air, water and earth), which he proclaimed to be composed of various aggregates of triangles, and made various compounds of these into what he called the Body of the Universe.

In recent years, more emphasis has been placed on Plato’s unwritten teachings, which were passed on orally to his students and not included in the dialogues (on several occasions, Plato stressed that the written transmission of knowledge was faulty and inferior to the spoken logos). We have at least some idea of this from reports by his students, Aristotle and others, and from the continuity between his teachings and the interpretations of Plotinus and the Neo-Platonists. One recurring theme is that the first principle of everything, including the causation of good and of evil and of the Forms themselves, is the One (the cause of the essence of the Forms). It can be argued, then, that Plato’s concept of God affirms Monotheism, although he also talked of an Indefinite Duality (which he also called Large and Small).

In Epistemology, although some have imputed to Plato the remarkably modern analytic view that knowledge is justified true belief, Plato more often associated knowledge with the apprehension of unchanging Forms and their relationships to one another. He argued that knowledge is always proportionate to the realm from which it is gained, so that, if one derives an account of something experientially then (because the world of sense is always in flux) the views attained will be mere opinions. On the other hand, if one derives an account of something by way of the non-sensible Forms, then the views attained will be pure and unchanging (because the Forms are unchanging too). In several dialogues, Plato also floated the idea that knowledge is a matter of recollection (“anamnesis”), and not of learning, observation or study. Thus, knowledge is not empirical, but essentially comes from divine insight.

To a large extent, it is Plato who is responsible for the modern view of the Sophist as a greedy and power-seeking instructor who uses rhetorical sleight-of-hand and ambiguities of language in order to deceive, or to support fallacious reasoning. He was at great pains in his dialogues to exonerate Socrates from accusations of Sophism. Plato, and Aristotle after him, also believed in a kind of Moral Universalism(or Moral Absolutism), opposing the Moral Relativism of the Sophists.

In Ethics, Plato had a teleological or goal-orientated worldview, and the aim of his Ethics was therefore to outline the conditions under which a society might function harmoniously. He considered virtue to be an excellence of the soul, and, insofar as the soul has several components (e.g. reason, passions, spirit), there will be several components of its excellence: the excellence of reason is wisdom; the excellence of the passions are attributes such as courage; and the excellence of the spirit is temperance. Finally, justice is that excellence which consists in a harmonious relation of the other three parts. He believed, then, that virtue was a sort of knowledge (the knowledge of good and evil) that is required to reach the ultimate good (or eudaimonia), which is what all human desires and actions aim to achieve, and as such he was an early proponent of Eudaimonism or Virtue Ethics.

Plato’s philosophical views had many societal and political implications, especially on the idea of an ideal state or government (much influenced by the model of the severe society of Sparta), although there is some discrepancy between his early and later views on Political Philosophy. Some of his most famous doctrines are contained in the “Republic” (the earliest example of a Utopia, dating from his middle period), as well as in the later “Statesman” and the “Laws”.

In general terms, Plato drew parallels between the tripartite structure of the individual soul and body (“appetite-stomach”, “spirit-chest” and “reason-head”) and the tripartite class structure of societies. He divided human beings up, based on their innate intelligence, strength and courage, into: the Productive (Workers), labourers, farmers, merchants, etc, which corresponds to the “appetite-stomach”; the Protective (Warriors), the adventurous, strong and brave of the armed forces, which corresponds to the “spirit-chest”; and the Governing (Rulers or Philosopher Kings), the intelligent, rational, self-controlled and wise, who are well suited to make decisions for the community, which corresponds to the “reason-head”. The Philosophers and the Warriors together are thus the Guardians of Plato’s ideal state.

Plato concluded that reason and wisdom (rather than rhetoric and persuasion) should govern, thus effectively rejecting the principles of Athenian democracy (as it existed in his day) as only a few are fit to rule. A large part of the “Republic” then addresses how the educational system should be set up (his important contribution to the Philosophy of Education) to produce these Philosopher Kings, who should have their reason, will and desires united in virtuous harmony (a moderate love for wisdom, and the courage to act according to that wisdom). The Philosopher King image has been used by many after Plato to justify their personal political beliefs.

He also made some interesting arguments about states and rulers. He argued that it is better to be ruled by a tyrant (since then there is only one person committing bad deeds) than by a bad democracy (since all the people are now responsible for the bad actions). He predicted that a state which is made up of different kinds of souls will tend to decline from an aristocracy (rule by the best) to a timocracy (rule by the honourable), then to an oligarchy (rule by the few), then to a democracy (rule by the people) and finally to tyranny (rule by a single tyrant).

In the “Laws”, probably Plato’s last work and a work of enormous length and complexity, he concerned himself with designing a genuinely practicable (if admittedly not ideal) form of government, rather than with what a best possible state might be like. He discussed the empirical details of statecraft, fashioning rules to meet the multitude of contingencies that are apt to arise in the “real world” of human affairs, and it marks a rather grim and terrifying culmination of the totalitarian tendencies in his earlier political thought.

Plato’s views on Aesthetics were somewhat compromised and he had something of a love-hate relationship with the arts. He believed that aesthetically appealing objects were beautiful in and of themselves, and that they should incorporate proportionharmony and unity among their parts. As a youth he had been a poet, and he remained a fine literary stylist and a great story-teller. However, he found the arts threatening in that they are powerful shapers of character. Therefore, to trainand protect ideal citizens for an ideal society, he believed that the arts must be strictly controlled, and he proposed excluding poets, playwrights and musicians from his ideal Republic, or at least severely censoring what they produced. He also argued that art is merely imitation of the objects and events of ordinary life, effectively a copy of a copy of an ideal Form. Art is therefore even more of an illusion than is ordinary experience, and so should be considered at best entertainment, and at worst a dangerous delusion.

.Plato’s consideration of epistemology, or the theory of knowledge, comes mainly in the “Theaetetus”. In it, he (through the person of Socrates) considers three different theses – that knowledge is perception, that knowledge is true judgement, and that knowledge is true judgement together with an account – refuting each of them in turn, without leaving us with any definitive conclusion or solution. One is left, though, with the impression that Plato’s own view is probably that what constitutes knowledge is actually a combination or synthesis of all these separate theses.

Although the study of Plato’s thought continued with the Neo-Platonists, his reputation was completely eclipsed during Medieval times by that of his most famous student, Aristotle. This is mainly because Plato’s original writings were essentially lostto Western civilization until they were brought from Constantinople in the century before its fall by the Greek Neo-Platonist George Gemistos Plethon (c. 1355 – 1452). The Medieval Scholastic philosophers, therefore, did not have access to the works of Plato, nor the knowledge of Greek needed to read them. Only during the Renaissance, with the general resurgence of interest in classical civilization, did knowledge of Plato’s philosophy become widespread again in the West, and many of the greatest early modern scientists and artists who broke with Scholasticism saw Plato’s philosophy as the basis for progress in the arts and sciences. By the 19th Century, Plato’s reputation was restored, and at least on par with Aristotle’s.

Plato’s influence has been especially strong in mathematics and the sciences. Although he made no important mathematical discoveries himself, his belief that mathematics provides the finest training for the mind was extremely important in the development of the subject (over the door of the Academy was written, “Let no one unversed in geometry enter here”). He concentrated on the idea of “proof”, insisting on accurate definitions and clear hypotheses, all of which laid the foundations for the systematic approach to mathematics of Euclid (who flourished around 300 B.C.)

However, Plato also helped to distinguish between pure and applied mathematics by widening the gap between “arithmetic” (now called Number Theory) and “logistic” (now called Arithmetic). Plato’s resurgence in the Modern era further inspired some of the greatest advances in Logic since Aristotle, primarily through Gottlob Frege and his followers Kurt Gödel (1906 – 1978), Alonzo Church (1903 – 1995) and Alfred Tarski (1901 – 1983).

Plato’s name is also attached to the “Platonic solids” (convex regular polyhedrons), especially in the “Timaeus”, in which the cube, tetrahedron, octahedron, and icosahedron are given as the shapes of the atoms of earth, fire, air and water, with the fifth Platonic solid, the dodecahedron, being his model for the whole universe. Plato’s beliefs as regards the universe were that the stars, planets, Sun and Moon all move round the Earth in crystalline spheres. The sphere of the Moon was closestto the Earth, then the sphere of the Sun, then Mercury, Venus, Mars, Jupiter, Saturn and furthest away was the sphere of the stars. He believed that the Moon shines by reflected sunlight.

Socrates (464 – 399 B.C.)


socratesSocrates (c. 469 – 399 B.C.) was a hugely important Greek philosopher from the Classical period (often known as the Socratic period in his honour). Unlike most of the Pre-Socratic philosophers who came before him, who were much more interested in establishing how the world works, Socrates was more concerned with how people should behave, and so was perhaps the first major philosopher of Ethics.



Socrates was born, as far as we know, in Athens around 469 B.C. Our knowledge of his life is sketchy and derives mainly from three contemporary sources, the dialogues of Plato and Xenophon (c. 431 – 355 B.C.), and the plays of Aristophanes (c. 456 – 386 B.C.). According to Plato, Socrates’ father was Sophroniscus (a sculptor and stonemason) and his mother was Phaenarete (a midwife). His family was respectable in descent, but humble in means. He appears to have had no more than an ordinary Greek education (reading, writing, gymnastics and music, and, later, geometry and astronomy) before devoting his time almost completely to intellectual interests.

He is usually described as unattractive in appearance and short in stature, and he apparently rarely washed or changed his clothes. But he did nevertheless marry Xanthippe, a woman much younger than he and renowned for her shrewishness(Socrates justified his marriage on the grounds that a horse-trainer needs to hone his skills on the most spirited animals). She bore for him three sons, LamproclesSophroniscus and Menexenus, who were all were quite young children at the time of their father’s trial and death and, according to Aristotle, they turned out unremarkable, silly and dull.

It is not known for sure who his teachers were, but he seems to have been acquainted with the doctrines of Parmenides, Heraclitus and Anaxagoras. Plato recorded the fact that Socrates met Zeno of Elea and Parmenides on their trip to Athens, probably in about 450 B.C. Other influences which have been mentioned include a rhetorician named Prodicus, a student of Anaxagoras called Archelaus, and two women (besides his mother): Diotima (a witch and priestess from Mantinea who taught him all about “eros” or love), and Aspasia (the mistress of the Greek statesman Pericles, who taught him the art of funeral orations).

It is not clear how Socrates earned a living. Some sources suggest that he continued the profession of stonemasonry from his father. He apparently served for a time as a member of the senate of Athens, and he served (and reportedly distinguished himself) in the Athenian army during three campaigns at PotidaeaAmphipolis and Delium. However, most texts seem to indicate that Socrates did not work, devoting himself solely to discussing philosophy in the squares of Athens. Using a method now known as the Socratic Method (or Socratic dialogue or dialectic), he grew famous for drawing forth knowledge from his students by pursuing a series of questions and examining the implications of their answers. Often he would question people’s unwarranted confidence in the truth of popular opinions, but usually without offering them any clear alternative teaching. Aristophanes portrayed Socrates as running a Sophist school and accepting payment for teaching, but other sources explicitly deny this.

The best known part of Socrates’ life is his trial and execution. Despite claiming complete loyalty to his city, Socrates’ pursuit of virtue and his strict adherence to truth clashed with the course of Athenian politics and society (particularly in the aftermath of Athens’ embarrassing defeats in the Peloponnesian War with Sparta). Socrates raised questions about Athenian religion, but also about Athenian democracy and, in particular, he praised Athens’ arch-rival Sparta, causing some scholars to interpret his trial as an expression of political infighting. However, it more likely resulted from his self-appointed position as Athens’ social and moral critic, and his insistence on trying to improve the Athenians’ sense of justice (rather than upholding the status quo and accepting the development of immorality). His “crime” was probably merely that his paradoxical wisdom made several prominent Athenians look foolish in public.

Whatever the motivation, he was found guilty (by a narrow margin of 30 votes out of the 501 jurors) of impiety and corrupting the minds of the youth of Athens, and he was sentenced to death by drinking a mixture containing poison hemlock in 399 B.C., at the age of 70. Although he apparently had an opportunity to escape, he chose not to, believing that a true philosopher should have no fear of death, that it would be against his principles to break his social contract with the state by evading its justice, and that he would probably fare no better elsewhere even if he were to escape into exile.



As has been mentioned, Socrates himself did not write any philosophical texts, and our knowledge of the man and his philosophy is based on writings by his students and contemporaries, particularly Plato’s dialogues, but also the writings of Aristotle, Xenophon and Aristophanes. As these are either the partisan philosophical texts of his supporters, or works of dramatic rather than historically accurate intent, it is difficult to find the “real” Socrates (often referred to as the “Socratic problem”). In Plato’s Socratic Dialogues in particular, it is well-nigh impossible to tell which of the views attributed to Socrates are actually his and which Plato’s own.

Perhaps Socrates’ most important and enduring single contribution to Western thought is his dialectical method of inquiry, which he referred to as “elenchus”(roughly, “cross-examination”) but which has become known as the Socratic Method or Socratic Debate (although some commentators have argued that Protagoras actually invented the “Socratic” method). It has been called a negative method of hypothesis elimination, in that better hypotheses are found by steadily identifying and eliminating those which lead to contradictions. Even today, the Socratic Method is still used in classrooms and law schools as a way of discussing complex topics in order to expose the underlying issues in both the subject and the speaker. Its influence is perhaps most strongly felt today in the use of the Scientific Method, in which the hypothesis is just the first stage towards a proof.

At its simplest, the Socratic Method is used to solve a problem by breaking the problem down into a series of questions, the answers to which gradually distill better and better solutions. Both the questioner and the questioned explore the implications of the other’s positions, in order to stimulate rational thinking and illuminate ideas. Thus, Socrates would counter any assertion with a counterexample which disproves the assertion (or at least shows it to be inadequate). This would lead to a modified assertion, which Socrates would then test again with another counterexample. Through several iterations of this kind, the original assertion is continually adjusted and becomes more and more difficult to refute, which Socrates held meant that it was closer and closer to the truth.

Socrates believed fervently in the immortality of the soul, and he was convinced that the gods had singled him out as a kind of divine emissary to persuade the people of Athens that their moral values were wrong-headed, and that, instead of being so concerned with their families, careers, and political responsibilities, they ought to be worried about the “welfare of their souls”. However, he also questioned whether “arete” (or “virtue”) can actually be taught as the Sophists believed. He observed that many successful fathers (such as the prominent military general Pericles, for example) did not produce sons of their own quality, which suggested to him that moral excellence was more a matter of divine bequest than parental nurture.

He often claimed that his wisdom was limited to an awareness of his own ignorance, (although he did claim to have knowledge of “the art of love“). Thus, he never actually claimed to be wise, only to understand the path a lover of wisdom must take in pursuing it. His claim that he knew one and only one thing, that he knew nothing, may have influenced the later school of Skepticism. He saw his role, not as a teacher or a theorist, but as analogous to a midwife who could bring the theories of others to life, although to do so he would of course need to have experience and knowledge of that of which he talked. He believed that anyone could be a philosopher, not just those who were highly trained and educated, and indeed that everyone had a duty to ask philosophical questions (he is famously quoted as claiming that “the unexamined life is not worth living“).

Many of the beliefs traditionally attributed to the historical Socrates have been characterized as “paradoxical” because they seem to conflict with common sense, such as: no-one desires evil, no-one errs or does wrong willingly or knowingly; all virtue is knowledge; virtue is sufficient for happiness. He believed that wrongdoing was a consequence of ignorance and those who did wrong knew no better (sometimes referred to as Ethical Intellectualism). He believed the best way for people to live was to focus on self-development rather than the pursuit of material wealth, and he always invited others to try to concentrate more on friendships and a sense of true community. He was convinced that humans possessed certain virtues(particularly the important philosophical or intellectual virtues), and that virtue was the most valuable of all possessions, and the ideal life should be spent in search of the Good (an early statement of Eudaimonism or Virtue Ethics).

Socrates’ political views, as represented in Plato’s dialogue “The Republic”, were strongly against the democracy that had so recently been restored in the Athens of his day, and indeed against any form of government that did not conform to his ideal of a perfect republic led by philosophers, who he claimed were the only type of person suitable to govern others. He believed that the will of the majority was not necessarily a good method of decision-making, but that it was much more important that decisions be logical and defensible. However, these may be more Plato’s own views than those of Socrates, “The Republic” being a “middle period” work often considered to be not representative of the views of the historical Socrates.

In Plato’s “early” dialogue, “Apology of Socrates”, Socrates refused to pursue conventional politics, on the grounds that he could not look into the matters of others(or tell people how to live their lives) when he did not yet understand how to live his own. Some have argued that he considered the rule of the “Thirty Tyrants” (who came to power briefly during his life, led by Critias, a relative of Plato and a one-time student of Socrates himself) even less legitimate than the democratic senate that sentenced him to death.

Likewise, in the dialogues of Plato, Socrates often appears to support a mystical side, discussing reincarnation and the mystery religions (popular religious cults of the time, such as the Eleusinian Mysteries, restricted to those who had gone through certain secret initiation rites), but how much of this is attributable to Socrates or to Plato himself is not (and never will be) clear. Socrates often referred to what the Greeks called a “daemonic sign”, a kind of inner voice he heard only when he was about to make a mistake (such as the sign that he claimed prevented him from entering into politics). Although we would consider this to be intuition today, Socrates thought of it as a form of “divine madness”, the sort of insanity that is a gift from the gods and gives us poetrymysticismlove and even philosophy itself.

Socrates’ views were instrumental in the development of many of the major philosophical movements and schools which came after him, particularly the Platonism of his principle student Plato, (and the Neo-Platonism and Aristotelianism it gave rise to). His idea of a life of austerity combined with piety and morality (largely ignored by Plato and Aristotle) was essential to the core beliefs of later schools like Cynicism and Stoicism. Socrates’ stature in Western Philosophy returned in full force with the Renaissance and the Age of Reason in Europe when political theory began to resurface under such philosophers as John Locke and Thomas Hobbes. Aristippus of Cyrene (c. 435 – 360 B.C.), the founder of the school of Hedonism was also a pupil of Socrates, although he rather skewed Socrates’ teaching.