The Theory of Forms

A Conception of the Good Life

The Death of Socrates, by Jacques-Louis David, 1787. The Death of Socrates

Plato is seated at the end of the bed. Socrates reaches for the hemlock. His friends are weeping. In the Phaedo, Socrates tells Crito not to forget that "we owe a cock to Asclepius" (in gratitude, it seems, for healing the illness that is life in a body). Crito replies that "[i]t shall be done." He asks Socrates whether he has "anything else to say," but Socrates does not reply. He has died, and Phaedo brings his account to a close: "[s]uch was the end of our comrade, a man who, we would say, was of all those we have known, the best, and also the wisest and most upright" (Phaedo 118a).

"I [Phaedo] was not filled with pity as I might naturally be when present at the death of a friend [Socrates]; since he seemed to me to be happy (εὐδαίμων), both in his bearing and his words, he was meeting death so fearlessly and nobly. And so I thought that even in going to the abode of the dead he was not going without the protection of the gods, and that when he arrived there it would be well with him, if it ever was well with anyone" (Phaedo 58e).
The Phaedo portrays Socrates on the day of his death.

The primary argument in the dialogue is that "the lover of wisdom" (φιλόσοφος) should not fear death. His interlocutors, Simmias and Cebes, are Pythagoreans. Socrates argues that death is the separation of the soul from the body and that the body stands in the way of wisdom. In death, the soul has the knowledge of "forms" the lover of wisdom seeks.

In this way, in the Phaedo, there is some explanation of what the good life is. The wisdom the lover of wisdom seeks transforms the soul so that the human being engages in a certain intellectual activity. This intellectual activity imitates the existence the soul enjoys in its natural and disincarnate state, a state in which is somehow completely characterized by knowledge of forms. The good life for a human being is the existence that, as much as possible, resembles the disincarnate existence of the soul in which it is fixed in "contemplation" (θεωρία).

We can begin to understand what Plato has in mind, and why he thinks of the good life in this initially way, if we first consider what the Greek noun θεωρία means.

In its ordinary use, the noun θεωρία means "looking at, viewing, or beholding." It transliterates as theoria and is the root of the English noun theory. The translation of θεωρία as "contemplation" follows the practice of translating θεωρία into Latin as contemplatio.

In a story Cicero tells, for example, in which the ruler of Phlius learns the meaning of the term φιλόσοφος, which was uncommon, Pythagoras explains that "a special few who, counting all else as nothing, closely scanned the nature of things; these men gave themselves the name of lovers of wisdom (for that is the meaning of the word philosopher); and just as at the games the men of truest breeding looked on without any self-seeking, so in life the contemplation and understanding of nature far surpassed all other pursuits" (Tusculan Disputations V.9).

Orphism and Pythagoreanism

The view of the soul in the Phaedo, according to which it is in a better state when it is freed from practical concerns, seems to have connections to Orphism and Pythagoreanism.

In the Orphic religious movement (which takes its name form the (maybe mythical) Orpheus), the afterlife is not bad and that the soul can be cleansed of the body. This idea, which is contrary to the picture of the afterlife in Homer, is also part of Pythagoreanism.


Simmias and Cebes are students of Philolaus (Phaedo 61d). Philolaus was a Pythagorean from Croton (in what is now the south of Italy) and a contemporary of Socrates. Pythagoras founded his school in Croton in about 530 BCE.

In the Crito, at 45b, Simmias and Cebes are said to have brought money to aid Socrates in escaping from jail.



Orpheus was said to born of the Muse, Calliope. To be "musical" is to be skilled an art over which the Muses presided. The word is used generally of a person of letters and accomplishments. The opposite is to be ἀμαθής. To be ἀμαθής is to be "unlearned, ignorant, stupid, or boorish."
In the Apology, Socrates says he is willing to die many times over if it meant he would meet Orpheus in the afterlife (41a). In the Meno, at 81a-b, in connection with the Theory of Recollection, Socrates seems to have the Orphics in mind. He tells Meno, in his introduction to the theory, that he has heard from "certain priests and priestesses" that "the soul of man is immortal, and at one time comes to an end, which is called dying, and at another is born again, but never perishes." In the Phaedo, on the day of his death, his final conversation is with the Pythagoreans Simmias and Cebes. Socrates tries to show them that the lover of wisdom should not fear death and that those who pursue the "love of wisdom" (φιλοσοφία) correctly are practicing in life for their existence in death (61c-d, 63b-c, 63e-64a). Socrates has said previously, at 60e-61a, that he has had a dream in which he was instructed to cultivate the Muses and that he thought the instruction was to do what he had been doing because the "love of wisdom" (φιλοσοφία) is the greatest form of (what was called) "music" (μουσικῆς).

The Life of Contemplation

"[P]hilosophy (φιλοσοφία) sees that the most dreadful thing about the imprisonment in the body is the fact that it is caused by the lusts (ἐπιθυμίας) of the flesh, so that the prisoner is the chief assistant in his own imprisonment. ... The soul of the true philosopher ... stands aloof from pleasures and lusts and griefs and fears (ἡδονῶν τε καὶ ἐπιθυμιῶν καὶ λυπῶν καὶ φόβων), so far as it can, considering that when anyone has violent pleasures or fears or griefs or lusts he suffers from them not merely what one might think--for example, illness or loss of money spent or his lusts--but he suffers the greatest and most extreme evil and does not take it into account. ... The evil is that the soul of every man, when it is greatly pleased or pained by anything, is compelled to believe that the object which caused the emotion (πάσχῃ) is very distinct and very true; but it is not. ... Each pleasure or pain bonds the soul as with a nail to the body and rivets it on and makes it corporeal, so that it fancies the things are true which the body says are true. For because it has the same beliefs and pleasures as the body it is compelled to adopt also the same habits and mode of life (ἐκ γὰρ τοῦ ὁμοδοξεῖν τῷ σώματι καὶ τοῖς αὐτοῖς χαίρειν ἀναγκάζεται οἶμαι ὁμότροπός τε καὶ ὁμότροφος γίγνεσθαι), and can never depart in purity to the other world, but must always go away contaminated with the body; and so it sinks quickly into another body again and grows into it, like seed that is sown. Therefore it has no part in the communion with the divine and pure and absolute. ... This, Cebes, is the reason why the true lovers of knowledge are temperate and brave .... For the soul of the philosopher would not reason as others do, and would not think it right that philosophy should set it free and that then when set free it should give itself again into bondage to pleasure and pain and engage in futile toil.... No, his soul believes that it must gain peace from these emotions, must follow reason (λογισμῷ) and abide always in it, beholding that which is true and divine and not a matter of opinion (τὸ ἀληθὲς καὶ τὸ θεῖον καὶ τὸ ἀδόξαστον), and making that its only food; and in this way it believes it must live, while life endures, and then at death pass on to that which is akin to itself and of like nature, and be free from human ills" (Phaedo 82e). Plato, it seems, in the Phaedo, understands a human being as an immortal soul in a mortal body. In its disincarnate state, the soul is fixed in contemplation of forms. When the soul enters the body, it forgets itself and its good and wrongly takes on the concerns of the body. Socrates, as Plato seems to understand him, lived in a way that corrects this mistake. In neglecting the things ordinarily thought to be good, and by spending his life in the love of wisdom thinking about forms, his existence is like the one he expects to have outside the body.

This makes it a little clearer how Plato understands the suggestion in the early dialogues that the person who is just and has the rest of the virtues of character chooses wisely and thus arranges things in his life so that he is "happy" (εὐδαίμων). The person who lives in terms of these virtues arranges things in his life so that he has time for contemplation of the forms. Socrates gives this explanation in the passage that sometimes is called his "second" defense.

"I suspect that this is not the right way to purchase virtue (ἀρετὴν), by exchanging pleasures for pleasures, and pains for pains, and fear for fear, and greater for less, as if they were coins, but the only right coinage, for which all those things must be exchanged and by means of and with which all these things are to be bought and sold, is in fact wisdom; and courage and temperance and justice and, in short, true virtue exist only with wisdom, whether pleasures and fears and other things of that sort are added or taken away. And virtue which consists in the exchange of such things for each other without wisdom, is but a painted imitation of virtue and is really slavish and has nothing healthy or true in it; but whereas, truth to tell, temperance and justice and courage may in fact be a kind of purification of all such things, and wisdom itself a kind of purification (καθαρμός). And I fancy that those men who established the mysteries were not unenlightened, but in reality had a hidden meaning when they said long ago that whoever goes uninitiated and unsanctified to the other world will lie in the mire, but he who arrives there initiated and purified will dwell with the gods. For as they say in the mysteries, 'the thyrsus-bearers are many, but the mystics few'; and these mystics are, I believe, those who have practiced philosophy correctly (οἱ πεφιλοσοφηκότες ὀρθῶς). And I in my life have, so far as I could, left nothing undone, and have striven in every way to make myself one of them. But whether I have striven aright and have met with success, I believe I shall know clearly, when I have arrived there, very soon, God willing. There is my defense, then, Simmias and Cebes, to show that it is reasonable for me not to be grieved or troubled at leaving you..." (Phaedo 69a).

Socrates and the Inquiry into Nature

"When I was young, Cebes, I was tremendously eager for the kind of wisdom (σοφίας) they call inquiry about nature (περὶ φύσεως ἱστορίαν)" (Phaedo 96a).

Other than the remark in the Phaedo, there is little evidence to show that Socrates was ever "eager" for the inquiry into nature. Diogenes Laertius says Archelaus (a student of Anaxagoras) brought natural philosophy (φυσικὴν φιλοσοφίαν) to Athens and that Socrates was his student (Lives of the Philosophers II.4), and it is possible that Archelaus is the author of some of the views Aristophanes associates with Socrates in the Clouds. Plato, however, in the Apology, has Socrates deny he ever pursued the inquiry into nature. "For many accusers have risen up against me before you, who have been speaking for a long time, many years already, and saying nothing true.... [T]hey got hold of most of you in childhood, and accused me without any truth, saying, 'There is a certain Socrates, a wise man, a ponderer over the things in the air and one who has investigated the things beneath the earth and who makes the weaker argument the stronger'" (Apology 18b; cf. 19b, 23c, 26d).

"Generally speaking, he [Socrates] refused to reason about the way in which god contrives (μηχανᾶται) each of the celestial phenomena" (Xenophon, Memorabilia IV.7).
In the course of arguing that the soul survives death, Socrates sets out his intellectual autobiography as a prelude to a general discussion of generation and destruction. He says, in this autobiography, that he was interested in the inquiry into nature when he was young.

This interest in the inquiry into nature is surprising. The early dialogues give no hint Socrates was ever interested in the inquiry into nature. In fact, it is easy to get the impression he thought that such knowledge might be impossible and that even if it were possible, it would not be part of the wisdom he wants. Socrates' interest in the early dialogues is in ethical matters

Why does Plato represent Socrates as having been interested in the the inquiry into nature?

The answer, it seems, is that Plato wants to show that Socrates pointed the way to the existence of forms and to the proper understanding of the good life as the contemplation of forms.

Plato seems to think the inquirers into nature gave answers that betray a mistake of the kind to which Socrates calls attention in the early dialogues. Socrates, in these dialogues, explains that he looking for what is universal in some ethical matter, not for something that manifests this universal in some particular circumstance. He tells Euthyphro, for example, not to reply to the "What is piety?" question by citing "one or two out of all the numerous actions that are pious," but to tell him "about the form itself by which all pious things are pious" (Euthyphro 6d).

As Plato portrays him, the questions Socrates pursues when in his youth he was interested in the inquiry into nature are not explicitly the "What is it?" questions he raises in he early dialogues.

"The physicist and the dialectician will offer different definitions, e.g., in answer to the question what is anger. The latter will call it a craving for retaliation, or something like that; the former will describe it as a surging of the blood and heat round the heart. The one is describing the matter, the other the form and account" (Aristotle, On the soul I.403a).

  "[H]e would say, 'Stranger from Elis, is it not by justice that the just are just?' So answer, Hippias, as though he were asking the question.
  I shall answer that it is by justice.
  'Then this--I mean justice--is something?'
  Certainly.
  'Then, too, by wisdom the wise are wise and by the good all things are good, are they not?'
  Of course.
  'And justice, wisdom, and so forth are something; for the just, wise, and so forth would not be such by them, if they were not something.'
  To be sure, they are something.
  'Then are not all beautiful things beautiful by the beautiful?'
  Yes, by the beautiful.
  By the beautiful, which is something?'
  Yes, for what alternative is there?
  'Tell me, then, stranger,' he will say, 'what is this, the beautiful?'" ( Hippias Major 287c).

"If anyone says to me [Socrates] that a given thing is beautiful because it has a blooming color, or a shape, or something else like that, I dismiss those other things, for all those things confuse me, and I hold simply and plainly and perhaps foolishly to this, that nothing else makes it beautiful but the presence or communion (call it which you please) of the beautiful itself (αὐτὸ τὸ καλόν), however it may have been gained; about the way in which it happens, I make no positive statement as yet, but I do insist that beautiful things are made beautiful by the beautiful" (Phaedo 100c).
He says he went back and forth with the following kinds of questions and answers. "Do heat and cold, by a sort of fermentation, bring about the organization of animals, as some people say? Is the blood, or air, or fire by which we think? Or is it none of these, and does the brain furnish the sensations of hearing and sight and smell, and do memory and opinion arise from these, and does knowledge come from memory and opinion in a state of rest" (Phaedo 96b).

It is not very clear how these questions and answers are to be understood, but maybe the idea is that they are explanations of something in terms of its material. Empedocles, for example, says that "the blood around the heart is for humans their thought" (DK 31 B 105 = D240; cf. Homer, Iliad 23.103-104). So, about thinking, the question and answer is

What is thinking in a human being? "[T]he blood [is that] by which we think."

This answer makes a kind of mistake Socrates' interlocutors make in connection with the search for definitions. Thinking may involve "the blood" in some instances of thinking, but the presence of "the blood" around the heart is not what thinking in a human being is.

Plato's intention, it seems, is that by portraying Socrates as having once been interested in the inquiry into nature, and by having him abandon this inquiry because it makes the kind of mistake his interlocutors make in the early dialogues, is to show that Socrrates took a step toward the conclusion that the understanding of reality in the inquiry into nature is incomplete. What makes it true that something is thinking (or that some action is pious or courageous) is the presence of something that does not exist among the "heat," "cold," "blood," "air," and other sensible objects that the inquirers into nature consider in their inquiries.

Two Kinds of Existences



"In his youth Plato first became acquainted with Cratylus and the Heraclitean doctrines--that the whole sensible world is always in a state of flux (ἀεὶ ῥεόντων), and that there is no knowledge of it--and in after years he still held these opinions. And when Socrates, disregarding the physical universe (τῆς ὅλης φύσεως) and confining his study to ethical questions, sought in this sphere for the universal (καθόλου) and was the first to concentrate upon definition. Plato followed him and assumed that the problem of definition is concerned not with any sensible thing but with entities of another kind; for the reason that there can be no common definition among the sensible things, as they are always changing. These entities he called Ideas (ἰδέας), and held that all sensible things are named after them and in virtue of their relation to them; for the plurality of things which bear the same name as the forms exist by participation in them" (Aristotle, Metaphysics I.6.987a).

"The theory of forms (εἰδῶν) occurred to those who enunciated it because they were convinced as by the doctrine of Heraclitus about reality, that all sensible things are always in a state of flux (ἀεὶ ῥεόντων); so that if there is to be any knowledge..., there must be certain other entities, besides sensible ones, which persist. For there can be no knowledge of that which is in flux. Now Socrates devoted his attention to the virtues of character, and was the first to seek a general definition of these. ... and he naturally inquired into the essence of things (τὸ τί ἐστιν); for he was trying to reason logically, and the starting-point of all logical reasoning is the essence. ... But whereas Socrates regarded neither universals nor definitions as existing in separation (χωριστὰ), they gave them a separate existence, and to these universals and definitions of existing things they gave the name of Ideas (ἰδέας)" (Aristotle, Metaphysics XIII.4.1078b).
Plato, it seems, thinks that the presence of of things called "forms" (είδη) makes things the way they are, that these forms are the "reality" of these features of sensible things, and that the existence of these "realities" is different from the existence of the sensible things.

   "Let us then, Cebes, turn to what we were discussing before. Is the reality itself (αὐτὴ ἡ οὐσία), whose reality we give an account in our dialectic process of question and answer, always the same or is it liable to change? Does the equal itself, the beautiful itself, what each thing itself is, the reality, ever admit of any change whatsoever? Or does what each of them is, being uniform and existing by itself, remain the same and never in any way admit of any change?
   It must necessarily remain the same, Socrates.
   But how about the many things, for example, men, or horses, or cloaks, or any other such things, which bear the same names as those objects and are called beautiful or equal or the like? Are they always the same? Or are they, in direct opposition to those others, constantly changing in themselves, unlike each other, and, so to speak, never the same?
   The latter, they are never the same.
   And you can see these and touch them and perceive them by the other senses, whereas the things which are always the same can be grasped only by the reasoning of the intellect (τῷ τῆς διανοίας λογισμῷ), and are invisible and not to be seen?
   Certainly that is true.
   Now, shall we assume two kinds of existences, one visible, the other invisible?
   Let us assume them, Socrates" (Phaedo 78c).

We can understand this conversation a little more clearly if we consider an example. Suppose we know what piety is, that it is what is appropriate with respect to the gods. In this case, given that certain actions are pious, they are appropriate with respect to the gods. This is the "form" the actions share. So although the actions appropriate with respect to the gods may change with the circumstances, the form these actions share is not subject to change. Further, we can begin to understand that this form is not sensible but is something we only discern in reason.

We still might wonder what it is for this form to exist. In answer, maybe to say that "the pious itself" exists is to say that piety is something. If we ask what this is, as Socrates does in the Euthyphro, the answer (we are assuming) is that piety is what is appropriate with respect to the gods. This object, which the theory calls a "form," is what all and only pious actions are.

This example makes the Theory of Forms a little easier to understand, but it does not show that the theory is true.   "Now how about such things as this, Simmias? Do we say justice itself is something, or not (φαμέν τι εἶναι δίκαιον αὐτὸ ἢ οὐδέ)?
  We certainly do.
  And beauty and goodness.
  Of course.
  Well, did you ever see anything of that kind with your eyes?
  Certainly not" (Phaedo 65d).
It is far from obvious that there are any of the objects that the theory calls "forms." When Socrates first talks about forms, he asks Simmias whether "we say the just itself is something." Simmias responds that "we certainly do," but this is not an argument.

The Good Life

Questions remain about how Plato understands the soul, forms, and contemplation, but his conception of the good life is a little clearer. It is a life that centers around thinking about forms. The Latin scientia, from which 'science' derives, which was a standard translation of the Greek ἐπιστήμη ("knowledge").

The φιλόσοφος is the φιλομαθής, Republic II.367b.
In this way, it is a little like the life of thinking about a theory one knows is true, where this thinking is like seeing or experiencing one of the great wonders of the world.

What is less clear, at this point, is the argument to show that this life is the good life.




Perseus Digital Library:

Plato, Phaedo, Parmenides.
Aristotle, Metaphysics

Henry George Liddell, Robert Scott, A Greek-English Lexicon:
εἶδος, eidos, noun, "that which is seen, form, shape"
εἶδος is from εἴδω, subjunctive of the perfect οἶδα, oida, verb, "have seen, found out, know," (Smyth, 1946)
θεωρία, theōria, noun, "viewing, beholding"
ἰδέα, idea, noun, "look of something, form"
ἰδέα is from ἰδεῖν, aorist infinitive of ὁράω , horaō, verb, "see, look, look at, behold, perceive"
μουσική, mousikē, noun, "art over which the Muses presided"
ουσία, ousia, noun, "stable being, immutable reality"
παράδειγμα, paradeigma, noun, "pattern, model"
ῥέω, rheō, verb, "to flow, run, stream, gush"

Arizona State University Library. Loeb Classical Library:
Early Greek Philosophy, Volume IV: Western Greek Thinkers, Part 1,
Early Greek Philosophy, Volume IV: Western Greek Thinkers, Part 2



"There is very little, if anything we know about the real Socrates. But if we know anything about him, it seems that he disapproved of natural philosophy, had no interest in metaphysics, was an extreme intellectualist..." (Michael Frede, "Plato’s Arguments and the Dialogue Form," 204-205. The Methods of Interpreting Plato and his Dialogues, 201-219. Oxford Studies in Ancient Philosophy, 1992. Supplementary Volume).



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