Plato was born, the son of Ariston and Perictione, in about 428 BC, the year after the death of the great statesman Pericles. His family, on both sides, was among the most distinguished in Athens. Ariston is said to have claimed descent from the god Poseidon through Codrus, the last king of Athens; on the mother's side, the family was related to the early Greek lawmaker Solon. Nothing is known about Plato's father's death. It is assumed that he died when Plato was a boy. Perictione apparently married as her second husband her uncle Pyrilampes, a prominent supporter of Pericles; and Plato was probably brought up chiefly in his house. Critias and Charmides, leaders among the extremists of the oligarchic terror of 404, were, respectively, cousin and brother of Perictione; both were friends of Socrates, and through them Plato must have known the philosopher from boyhood.
His own early ambitions --like those of most young men of his class-- were probably political. A conservative faction urged him to enter public life under its auspices, but he wisely held back. He was soon repelled by its members' violent acts. After the fall of the oligarchy, he hoped for better things from the restored democracy. Eventually, however, he became convinced that there was no place for a man of conscience in Athenian politics. In 399 BC the democracy condemned Socrates to death, and Plato and other Socratic men took temporary refuge at Megara with Eucleides, founder of the Megarian school of philosophy. The next few years are said to have been spent in extensive travels in Greece, in Egypt, and in Italy. Plato himself states that he visited Italy and Sicily at the age of 40 and was disgusted by the gross sensuality of life there but found a kindred spirit in Dion, brother-in-law of Dionysius I, the ruler of Syracuse.
The Academy and Sicily
In about 387 Plato founded the Academy as an institute for the systematic pursuit of philosophical and scientific teaching and research. He presided over it for the rest of his life. The Academy's interests were not limited to philosophy in a narrow sense but also extended to the sciences: there is evidence that Plato encouraged research in such diverse disciplines as mathematics and rhetoric. He himself lectured (on at least one occasion he gave a celebrated public lecture "On the Good"), and he set problems for his pupils to solve. The Academy was not the only such "school" in Athens--there are traces of tension between the Academy and the rival school of Isocrates.
The one outstanding event in Plato's later life was his intervention in Syracusan politics. On the death of Dionysius I in 367, Dion conceived the idea of bringing Plato to Syracuse as tutor to his brother-in-law's successor, Dionysius II, whose education had been neglected. Plato was not optimistic about the results; but because both Dion and Archytas of Tarentum, a philosopher-statesman, thought the prospect promising, he felt bound to risk the adventure. The plan was to train Dionysius II in science and philosophy and so to fit him for the position of a constitutional king who might hold Carthaginian encroachment on Sicily at bay. The scheme was crushed by Dionysius' natural jealousy of the stronger Dion, whom he drove into virtual banishment. Plato later paid a second and longer visit to Syracuse in 361-360, still in the hope of effecting an accommodation; but he failed, not without some personal danger. Dion then captured Syracuse by a coup de main in 357, but he was murdered in 354. Plato himself died in 348/347.
Of Plato's character and personality little is known, and little can be inferred from his writings. But it is worth recording that Aristotle, his most able pupil, described Plato as a man "whom it is blasphemy in the base even to praise," meaning that Plato was so noble a character that bad men should not even speak about him.
To his readers through the ages Plato has been important primarily as one of the greatest of philosophical writers; but to himself the foundation and organization of the Academy must have appeared to be his chief work. The Seventh Letter contrasts the impact of written works with that of the contact of living minds as a vehicle of philosophy, and it passes a comparatively unfavorable verdict on written works. Plato puts a similar verdict into the mouth of Socrates in the Phaedrus. He perhaps intended his dialogues in the main to interest an educated outside world in the more serious and arduous labors of his school.
All of the most important mathematical work of the 4th century was done by friends or pupils of Plato. The first students of conic sections, and possibly Theaetetus, the creator of solid geometry, were members of the Academy. Eudoxus of Cnidus --author of the doctrine of proportion expounded in Euclid's Elements, inventor of the method of finding the areas and volumes of curvilinear figures by exhaustion, and propounder of the astronomical scheme of concentric spheres adopted and altered by Aristotle-- removed his school from Cyzicus to Athens for the purpose of cooperating with Plato; and during one of Plato's absences he seems to have acted as the head of the Academy. Archytas, the inventor of mechanical science, was a friend and correspondent of Plato.
Nor were other sciences neglected. Speusippus, Plato's nephew and successor, was a voluminous writer on natural history; and Aristotle's biological works have been shown to belong largely to the early period in his career immediately after Plato's death. The comic poets found matter for mirth in the attention of the school to botanical classification. The Academy was particularly active in jurisprudence and practical legislation, as Plutarch testifies.
Plato sent Aristonymus to the Arcadians, Phormion to Elis, Menedemus to Pyrrha. Eudoxus and Aristotle wrote laws for Cnidus and Stagirus. Alexander asked Xenocrates for advice about kingship; the man who was sent to Alexander by the Asiatic Greeks and did most to incite him to his war on the barbarians was Delios of Ephesus, an associate of Plato.
The Academy survived Plato's death. Though its interest in science waned and its philosophical orientation changed, it remained for two and a half centuries a focus of intellectual life. Its creation as a permanent society for the prosecution of both humane and exact sciences has been regarded --with pardonable exaggeration-- as the first establishment of a university.
The most important formative influence to which the young Plato was exposed was Socrates. It does not appear, however, that Plato belonged as a "disciple" to the circle of Socrates' intimates. The Seventh Letter speaks of Socrates not as a "master" but as an older "friend," for whose character Plato had a profound respect; and he has recorded his own absence (through indisposition) from the death scene of the Phaedo. It may well be that his own vocation to philosophy dawned on him only afterward, as he reflected on the treatment of Socrates by the democratic leaders. Plato owed to Socrates his commitment to philosophy, his rational method, and his concern for ethical questions. Among other philosophical influences the most significant were those of Heracleitus and his followers, who disparaged the phenomenal world as an arena of constant change and flux, and of the Pythagoreans, with whose metaphysical and mystical notions Plato had great sympathy.
Plato had family connections with Pyrilampes, a Periclean politician, and with Critias, who became one of the most unscrupulous of the Thirty Tyrants who briefly ruled Athens after the collapse of the democracy.
Plato's early experiences covered the disastrous years of the Deceleian War, the shattering of the Athenian empire, and the fierce civil strife of oligarchs and democrats in the year of anarchy, 404-403. He was too young to have known anything by experience of the imperial democracy of Pericles and Cleon or of the tide of the Sophistic movement. It is certainly not from memory that he depicted Protagoras, the earliest avowed professional Sophist, or Alcibiades, a brilliant but unreliable Athenian politician and military commander. No doubt these early experiences helped to form the political views that were later expounded in the dialogues.
General features of the dialogues
The canon and text of Plato was apparently fixed at about the turn of the Christian Era. By reckoning the Letters as one item, the list contained 36 works, arranged in nine tetralogies. None of Plato's works has been lost, and there is a general agreement among modern scholars that a number of small items --Alcibiades I, Alcibiades II, Theages, Erastae, Clitopho, Hipparchus, and Minos-- are spurious. Most scholars also believe that the Epinomis, an appendix to the Laws, was written by the mathematician Philippus of Opus. The Hippias Major and the Menexenus are regarded as doubtful by some, though Aristotle seems to have regarded them as Platonic. Most of the 13 Letters are certainly later forgeries. About the authenticity of the Seventh Letter, which is by far the most important from the biographical and the philosophical points of view, there exists a long and unsettled controversy.
Order of composition
Plato's literary career extended over the greater part of a long life. The Apology was probably written in the early 380s. The Laws, on the other hand, was the work of an old man, and the state of its text bears out the tradition that Plato never lived to give it its final revision. Since there is no evidence that Plato began his career with a fully developed system, and since there is every reason to believe that his thoughts changed, the order in which the various dialogues were written takes on importance. Only through it can the development of Plato's thought be adequately charted. Unfortunately, Plato himself has given few clues to the order: he linked the Sophist and the Statesman with the Theaetetus externally as continuations of the conversation reported in that dialogue. Similarly, he seems to have linked the Timaeus with the Republic. And Aristotle noted that the Laws was written after the Republic.
Modern scholars, by the use of stylistic criteria, have argued that the Sophist, Statesman, Philebus, Timaeus (with its fragmentary sequel Critias), and Laws form a distinct linguistic group, belonging to the later years of Plato's life. The whole group must be later than the Sophist, which professes to be a sequel to the Theaetetus. Since the Theaetetus commemorates the death of the eminent mathematician after whom it is named (probably in 369 BC), it may be ascribed to c. 368, the eve of Plato's departure for Syracuse.
The earlier group of dialogues is generally believed to have ended with the Theaetetus and the closely related Parmenides. Apart from this, perhaps all that can be said with certainty is that the great dialogues, Symposium, Phaedo, and Republic (and perhaps also Protagoras), in which Plato's dramatic power was at its highest, mark the culmination of this first period of literary activity. The later dialogues are often thought to lack the dramatic and literary merits of the earlier but to compensate for this by an increased subtlety and maturity of judgment.
Persons of the dialogues
One difficulty that initially besets the modern student is that created by the dramatic form of Plato's writings. Since Plato never introduced himself into his own dialogues, he is not formally committed to anything asserted in them. The speakers who are formally bound by the utterances of the dialogues are their characters, of whom Socrates is usually the protagonist. Since all of these are real historical persons, it is reasonable to wonder whether Plato is reporting their opinions or putting his own views into their mouths, and, more generally, to ask what was his purpose in writing dialogues.
Some scholars have suggested that Plato allowed himself to develop freely in a dialogue any view that interested him for the moment without pledging himself to its truth. Thus Plato can make Socrates advocate hedonistic utilitarianism in the Protagoras and denounce it in the Gorgias. Others argue that some of Plato's characters, notably Socrates and Timaeus, are "mouthpieces" through whom he inculcates tenets of his own without concern for dramatic or historical propriety. Thus it has often been held that the theory of Ideas, the doctrine of recollection, and the notion of the tripartite soul were originated by Plato after the death of Socrates and consciously fathered on the older philosopher.
Thought of the earlier and later dialogues
There are undeniable differences in thought between the dialogues that are later than the Theaetetus and those that are earlier. But there are no serious discrepancies of doctrine between individual dialogues of the same period. Plato perhaps announced his own personal convictions on certain doctrines in the second group of dialogues by a striking dramatic device. In the Sophist and Statesman the leading part is taken by a visitor from Elea and in the Laws by an Athenian. These are the only anonymous, indeed almost certainly the only imaginary, personages of any moment in the whole of Plato's writings. It seems likely, therefore, that these two characters were left anonymous so that the writer could be free to use them as mouthpieces for his own teaching. Plato thus took on himself the responsibility for the logic and epistemology of the Sophist and of the Statesman and for the ethics and the educational and political theory of the Statesman and of the Laws.
Doctrine of Forms
There is a philosophical doctrine running through the earlier dialogues that has as its three main features the theory of knowledge as recollection, the conception of the tripartite soul, and, most importantly, the theory of Forms. The theory that knowledge is recollection rests on the belief that the soul is not only eternal but also preexistent. The conception of the tripartite soul holds that the soul consists of reason, appetite, and spirit (or will). Each part serves a purpose and has validity, but reason is the soul's noblest part; in order for man to achieve harmony, appetite and spirit must be subjected to the firm control of reason. The theory of Forms has as its foundation the assumption that beyond the world of physical things there is a higher, spiritual realm of Forms, or Ideas, such as the Form of Beauty or Justice. This realm of Forms, moreover, has a hierarchical order, the highest level being that of the Form of the Good. Whereas the physical world, perceived with the senses, is in constant flux and knowledge derived from it restricted and variable, the realm of Forms, apprehensible only by the mind, is eternal and changeless. Each Form is the pattern of a particular category of things in this world; thus there are Forms of man, stone, shape, color, beauty, and justice. Yet the things of this world are only imperfect copies of these perfect Forms.
In the Phaedo Socrates is made to describe the theory of Ideas as something quite familiar that he has for years constantly canvassed with his friends. In the dialogues of the second period, however, these tenets are less prominent, and the most important of them all, the theory of Forms, is in the Parmenides subjected to a searching set of criticisms. The question thus arises as to whether Plato himself had two distinct philosophies, an earlier and a later, or whether the main object of the first group of dialogues was to preserve the memory of Socrates, the philosophy there expounded being, in the main, that of Socrates --coloured, no doubt, but not consciously distorted, in its passage through the mind of Plato. On the second view, Plato had no distinctive Platonic philosophy until a late period in his life.
Socrates and Plato
It may be significant that the only dialogue later than the Theaetetus in which Socrates takes a leading part is the Philebus, the one work of the second group that deals primarily with the ethical problems on which the thought of Socrates had concentrated. This is usually explained by supposing that Plato was unwilling to make Socrates the exponent of doctrines that he knew to be his own property. It would, however, be hard to understand such misgivings if Plato had already been employing Socrates in that very capacity for years. It is notable, too, that Aristotle, who apparently knew nothing of an earlier and a later version of Platonism, attributed to Plato a doctrine that is quite unlike anything to be found in the first group of dialogues. It was also the view of Neoplatonic scholars that the theory of Ideas of the great earlier dialogues really originated with Socrates; and the fact that they did not find it necessary to argue the point may show that this had been the standing tradition of the Academy.
Few modern scholars, however, support this view. The differences between the early and late periods are not as great as they have sometimes been represented: although Plato's thought developed from the early to the late dialogues, it underwent no sudden dislocation. The ideas of the early period may have been inspired by Socrates, but they were Plato's own --for example, the theory of Forms could not have arisen with Socrates. Plato nevertheless attributed it to him because he saw it as the theoretical basis of what Socrates did teach.
The earlier dialogues
In the Republic, the greatest of all the dialogues that precede the Theaetetus, there are three main strands of argument deftly combined into an artistic whole --the ethical and political, the aesthetic and mystical, and the metaphysical. Other major dialogues belonging to this period give special prominence to one of these three lines of thought: the Phaedo to the metaphysical theme; the Protagoras and the Gorgias to the ethical and political; the Symposium and the Phaedrus to the aesthetic. But it should be noted that Plato's dialogues are not philosophical essays, let alone philosophical treatises, and they do not restrict themselves to a single topic or subject.
Dialogues of search
The shorter dialogues, dealing with more special problems, generally of an ethical character, mostly conform to a common type: a problem in moral philosophy, often that of the right definition of a virtue, is propounded, a number of tentative solutions are considered, and all are found to be vitiated by difficulties that cannot be dispelled. The reader is left, at the end of the conversation, aware of his ignorance of the very things that it is most imperative for a man to know. He has formally learned nothing but has been made alive to the confusions and fallacies in what he had hitherto been content to take as knowledge. The dialogues are "aporetic" and "elenctic": they pose puzzles (aporiai in Greek) without solving them, and Socrates' procedure consists in the successive refutation (elenchos) of the various views presented by his interlocutors.
The effect of these dialogues of search is thus to put the reader in tune with the spirit of Socrates, who had said that the one respect in which he was wiser than other men was in his keen appreciation of his own ignorance of the most important matters. The reader learns the meaning of Socrates' ruling principle that the supreme business of life is to "tend" the soul and his conviction that "goodness of soul" means knowledge of good and evil. The three dialogues directly concerned with the trial of Socrates have a further purpose. They are intended to explain to a puzzled public, as a debt of honour to his memory, why Socrates thought it a matter of conscience neither to withdraw from danger before his trial, nor to make a conciliatory defense, nor, after conviction, to avail himself of the opportunity of flight.
The Apology, or Defense, purports to give Socrates' speeches at his trial for impiety. In the Crito Socrates, in the condemned cell, explains why he will not try to escape paying the death penalty; the dialogue is a consideration of the source and nature of political obligation. The Euthyphro is represented as taking place just before Socrates' trial. Its subject is the virtue of "piety," or the proper attitude for men to take toward the gods. The Hippias Major propounds the question "What is the 'fine' (or 'beautiful')?" The Hippias Minor deals with the paradox that "wrongdoing is involuntary." The Ion discredits the poets, who create not "by science" but by a nonrational inspiration. The Menexenus, which professes to repeat a funeral oration learned from Aspasia, Pericles' mistress, is apparently meant as a satire on the patriotic distortion of history. The Charmides, Laches, and Lysis are typical dialogues of search. The question of the Charmides is what is meant by sophrosune, or "temperance," the virtue that is shown in self-command, in dutiful behaviour to parents and superiors, in balance, and in self-possession amid the turns of fortune. It seems that this virtue can be identified with the self-knowledge that Socrates had valued so highly. The Laches is concerned with courage, the soldier's virtue; and the Lysis examines in the same tentative way friendship, the relation in which self-forgetting devotion most conspicuously displays itself.
The question of whether words have meaning by nature or by convention is considered in the Cratylus --whether there is some special appropriateness of the sounds or forms of words to the objects they signify, or whether meaning merely reflects the usage of the community. Plato argues that, since language is an instrument of thought, the test of its rightness is not mere social usage but its genuine capacity to express thought accurately. The dialogue Euthydemus satirizes the "eristics" --those who try to entangle a person in fallacies because of the ambiguity of language. Its more serious purpose, however, is to contrast this futile logic chopping with the "protreptic," or hortatory, efforts of Socrates, who urges that happiness is guaranteed not by the possession of things but by the right use of them --and particularly of the gifts of mind, body, and fortune.
Ethical and political dialogues
The Gorgias, the Protagoras, and the Meno, like several of the lesser dialogues, give prominence to ethical and political themes. The Gorgias begins ostensibly as an inquiry into the nature and worth of rhetoric, the art of advocacy professed by Gorgias, and develops into a plea of sustained eloquence and logical power for morality --as against expediency-- as the sovereign rule of life, both private and public. It ends with an imaginative picture of the eternal destinies of the righteous and of the unrighteous soul.
Gorgias holds that rhetoric is the queen of all "arts." If the statesman skilled in rhetoric is clever enough, he can, though a layman, carry the day even against the specialist. Socrates, on the other hand, declares that rhetoric is not an art but a mere "knack" of humouring the prejudices of an audience. There are two arts conducive to health of soul, those of the legislator and of the judge. The Sophist counterfeits the first, the orator the second, by taking the pleasant instead of the good as his standard. The orator is thus not the wise physician of the body politic but its toady. This severe judgment is disputed by Polus, an ardent admirer of Gorgias, on the ground that the successful orator is virtually the autocrat of the community, and to be such is the summit of human happiness because he can do whatever he likes.
Socrates rejects this view. He does so by developing one of the "Socratic paradoxes": to suffer a wrong is an evil, but to inflict one is much worse. Thus if rhetoric is of real service to men, it should be most of all serviceable to an offender, who would employ it to move the authorities to inflict the penalties for which the state of his soul calls. All of this is in turn denied by Callicles, who proceeds to develop the extreme position of an amoralist. It may be a convention of the herd that unscrupulous aggression is discreditable and wrong, but "nature's convention" is that the strong are justified in using their strength as they please, while the weak "go to the wall." To Socrates, however, the creators of the imperialistic Athenian democracy were no true statesmen; they were the domestic servants of the democracy for whose tastes they catered; they were not its physicians. That would be a condition like that of the Danaids of mythology, who are punished in Hades by being set to spend eternity in filling leaking pitchers. A happy life consists not in the constant gratification of boundless desires but rather in the measured satisfaction of wants that are tempered by justice and sophrosune.
The Meno is nominally concerned with the question of what virtue is and whether it can be taught. But it is further interesting for two reasons: it states clearly the doctrine that knowledge is "recollection"; and it introduces as a character the democratic politician Anytus, the main author of the prosecution of Socrates.
Whether virtue can be taught depends on what virtue is. But the inquiry into virtue is difficult --indeed, the very possibility of inquiry is threatened by Meno's paradox concerning the quest for knowledge. If a person is ignorant about the subject of his inquiry, he could not recognize the unknown, even if he found it. If, on the other hand, the person already knows it, inquiry is futile because it is idle to inquire into what one already knows. But this difficulty would vanish if the soul were immortal and had long ago learned all truth, so that it needs now only to be reminded of truths that it once knew and has forgotten. To advance this argument, Socrates shows that a slave boy who has never studied geometry can be brought to recognize mathematical truths. He produces the right answer "out of himself." In general, knowledge is "recollection." Socrates next produces the hypothesis that virtue is knowledge and infers that it is teachable. But if virtue is knowledge, there must be professional teachers of it. Anytus insists that the Sophists, who claim to be such professionals, are mischievous impostors; and even the "best men" have been unable to teach it to their own sons. The Meno ends with a distinction between knowledge and true belief, and with the suggestion that virtue comes not by teaching but by divine gift.
The Protagoras gives the most complete presentation of the main principles of Socratic morality. In this dialogue Socrates meets the eminent Sophist Protagoras, who explains that his profession is the "teaching of goodness" --i.e., the art of making a success of one's life and of one's city. Socrates urges, however, that both common opinion and the failure of eminent men to teach "goodness" to their sons suggest that the conduct of life is not teachable. But the problem arises as to whether the various commonly recognized virtues are really different or all one. Protagoras is ultimately ready to identify all of the virtues except courage with wisdom or sound judgment. Socrates then attempts to show that, even in the case of courage, goodness consists in the fact that, by facing pain and danger, one escapes worse pain or danger. Thus all virtues can be reduced to the prudent computation of pleasures and of pains. Here, then, is a second "Socratic paradox": no one does wrong willingly --wrongdoing is a matter of miscalculation. It is a puzzling feature of this argument that Socrates appears to embrace a form of hedonism.
Metaphysical foundation of Plato's doctrine: "Phaedo"
In the works so far considered, the foundation of a Socratic moral and political doctrine is laid, which holds that the great concern of man is the development of a rational moral personality and that this development is the key to man's felicity. Success in this task, however, depends on rational insight into the true scale of good. The reason men forfeit felicity is that they mistake apparent good for real. If a man ever knew with assurance what the Good is, he would never pursue anything else; it is in this sense that "all virtue is knowledge." The philosophical moralist, who has achieved an assured insight into absolute Good, is thus the only true statesman, for he alone can tend to the national character. These moral convictions have a metaphysical foundation and justification. The principles of this metaphysics are expounded more explicitly in the following dialogues, in which a theory of knowledge and of scientific method is also discernible.
The object of the Phaedo is to justify belief in the immortality of the soul by showing that it follows from a fundamental metaphysical doctrine (the theory of Ideas, or the doctrine of Forms), which seems to afford a rational clue to the structure of the universe. Socrates' soul is identical with Socrates himself: the survival of his soul is the survival of Socrates --in a purified state. For his life has been spent in trying to liberate the soul from dependence on the body. In life, the body is always interfering with the soul's activity. Its appetites and passions interrupt the pursuit of wisdom and goodness.
There are four arguments for thinking that the soul survives death
First, there is a belief that the soul has a succession of many lives. The processes of nature in general are cyclical; and it is reasonable to suppose that this cyclicity applies to the case of dying and coming to life. If this were not so, if the process of dying were not reversible, life would ultimately vanish from the universe.
Second, the doctrine that what men call "learning" is really "recollection" shows, or at least suggests, that the soul's life is independent of the body.
Third, the soul contemplates the Forms, which are eternal, changeless, and simple. The soul is like the Forms. Hence it is immortal.
The fourth argument is the most elaborate. Socrates begins by recalling his early interest in finding the causes of being and change and his dissatisfaction with the explanations then current. He offers instead the Forms as causes. First, and safely, he says that something becomes, say, hot simply by participating in Heat. Then, a little more daringly, he is prepared to say that it becomes hot by participating in Fire, which brings Heat with it. Now if Fire brings Heat, it cannot accept Cold, which is the opposite of Heat. All this is then applied to the soul. Human beings are alive by participating in Life --and, more particularly, by having souls that bring Life with them. Since the soul brings Life, it cannot accept Death, the opposite of Life. But in that case the soul cannot perish and is immortal.
Aesthetic and mystical dialogues
Both the Symposium and the Phaedrus present the Forms in a special light, as objects of mystical contemplation and as stimuli of mystical emotion.
The immediate object of the Symposium, which records several banquet eulogies of eros (erotic love), is to find the highest manifestation of the love that controls the world in the mystic aspiration after union with eternal and supercosmic beauty. It depicts Socrates as having reached the goal of union and puts the figure of Alcibiades, who has sold his spiritual birthright for the pleasures of the world, in sharp opposition to him.
The main argument may be summarized thus: Eros is a reaching out of the soul to a hoped-for good. The object is eternal beauty. In its crudest form, love for a beautiful person is really a passion to achieve immortality through offspring by that person. A more spiritual form is the aspiration to combine with a kindred soul to give birth to sound institutions and rules of life. Still more spiritual is the endeavour to enrich philosophy and science through noble dialogue. The insistent seeker may then suddenly descry a supreme beauty that is the cause and source of all of the beauties so far discerned. The philosopher's path thus culminates in a vision of the Form of the Good, the supreme Form that stands at the head of all others.
Though the immediate subject of the Phaedrus is to show how a truly scientific rhetoric might be built on the double foundation of logical method and scientific study of human passions, Plato contrives to unite with this topic a discussion of the psychology of love, which leads him to speak of the Forms as the objects of transcendent emotion and, indeed, of mystical contemplation. The soul, in its antenatal, disembodied state, could enjoy the direct contemplation of the Forms. But sense experience can suggest the Form of Beauty in an unusually startling way: through falling in love. The unreason and madness of the lover mean that the wings of his soul are beginning to grow again; it is the first step in the soul's return to its high estate.
In the Republic the immediate problem is ethical. What is justice? Can it be shown that justice benefits the man who is just? Plato holds that it can. Justice consists in a harmony that emerges when the various parts of a unit perform the function proper to them and abstain from interfering with the functions of any other part. More specifically, justice occurs with regard to the individual, when the three component parts of his soul --reason, appetite, and spirit, or will --each perform their appropriate tasks; with regard to society, justice occurs when its component members each fulfill the demands of their allotted roles. Harmony is ensured in the individual when the rational part of his soul is in command; with regard to society, when philosophers are its rulers because philosophers --Platonic philosophers-- have a clear understanding of justice, based on their vision of the Form of the Good.
In the ethical scheme of the Republic three roles, or "three lives," are distinguished: those of the philosopher, of the votary of enjoyment, and of the man of action. The end of the first is wisdom; of the second, the gratification of appetite; and of the third, practical distinction. These reflect the three elements, or active principles, within a man: rational judgment of good; a multitude of conflicting appetites for particular gratifications; and spirit, or will, manifested as resentment against infringements both by others and by the individual's own appetites.
This tripartite scheme is then applied to determine the structure of the just society. Plato develops his plan for a just society by dividing the general population into three classes that correspond to the three parts of man's soul as well as to the three lives. Thus there are: the statesmen; the general civilian population that provides for material needs; and the executive force (army and police). These three orders correspond respectively to the rational, appetitive, and spirited elements. They have as their corresponding virtues wisdom, the excellence of the thinking part; temperance, that of the appetitive part (acquiescence of the nonrational elements to the plan of life prescribed by judgment); and courage, that of the spirited part (loyalty to the rule of life laid down by judgment). The division of the population into these three classes would not be made on the basis of birth or wealth but on the basis of education provided for by the state. By a process of examination each individual would then be assigned to his appropriate rank in correspondence with the predominant part of his soul.
The state ordered in this manner is just because each of the elements vigorously executes its own function and, in loyal contentment, confines itself within its limits. Such a society is a true aristocracy, or rule of the best. Plato describes successive deviations from this ideal as timocracy (the benign military state), oligarchy (the state dominated by merchant princes, a plutocracy), and democracy (the state subjected to an irresponsible or criminal will).
The training of the philosophical rulers would continue through a long and rigorous education because the vision of the Good requires extensive preparation and intellectual discipline. It leads through study of the exact sciences to that of their metaphysical principles. The central books of the Republic thus present an outline of metaphysics and a philosophy of the sciences. The Forms appear in the double character of objects of all genuine science and formal causes of events and processes. Plato expressly denied that there can be knowledge, in the proper sense, of the temporal and mutable. In his scheme for the intellectual training of the philosophical rulers, the exact sciences --arithmetic, plane and solid geometry, astronomy, and harmonics-- would first be studied for 10 years to familiarize the mind with relations that can only be apprehended by thought. Five years would then be given to the still severer study of "dialectic." Dialectic is, etymologically, the art of conversation, of question and answer; and according to Plato, dialectical skill is the ability to pose and answer questions about the essences of things. The dialectician replaces hypotheses with secure knowledge, and his aim is to ground all science, all knowledge, on some "unhypothetical first principle."
This principle is the Form of the Good, which, like the Sun in relation to visible things, is the source of the reality of all things, of the light by which they are apprehended, and also of their value. As in the Symposium, the Good is the supreme beauty that dawns suddenly upon the pilgrim of love as he draws near to his goal.
Dialogues of critical reconstruction
The two works that probably anticipate the dialogues of Plato's old age, the Parmenides and Theaetetus, display a remarkable difference of tone, clearly the result of a period of fruitful reconstruction.
The theory expounded in the Phaedo and Republic does not allow enough reality to the sensible world. These dialogues suppose that an entity capable of being sensed is a complex that participates in a plurality of Forms: what else it may be they do not say. Clearly, however, the relation between a thing and a Form (e.g., beauty), which has been called participation, needs further elucidation. In these dialogues truths of fact, of the natural world, have not yet had their importance recognized.
Plato clearly had an external motive for the reexamination of his system as well. The Parmenides, the Theaetetus, and the Sophist all reveal a special interest in the Eleatic philosophy, of which Parmenides was the chief representative. The doctrine of his friend Eucleides of Megara, like that of Parmenides, was that phenomena which can be apprehended by the senses are illusions with no reality at all. Continued reflection on this problem led straight to the discussion of the meaning of the copula "is" and the significance of the denial "is not," which is the subject of the Sophist.
Formally the Parmenides leads to an impasse. In its first half the youthful Socrates expounds the doctrine of the participation of things in Forms as the solution of the problem of the "one and many." ("How can this, that, and the other cat all be one thing--e.g., black?" "Each distinct cat participates in the unique Form of Blackness.") Parmenides raises what appear to be insoluble objections and hints that the helplessness of Socrates under his criticism arises from insufficient training in logic.
In the second half Parmenides gives an example of the logical training that he recommends. He takes for examination his own thesis, "The one is," and constructs upon it as basis an elaborate set of contradictions.
The Eleatic objections to the doctrine of participation are, first, that it does not really reconcile unity with plurality since it leads to a perpetual regress. It says that the many things that have a common predicate, or characteristic, participate in, or imitate, a single Form. But the Form itself also admits of a common predicate, and therefore a second Form must exist, participated in alike by the sensible things and the first Form, and so on, endlessly. Second, a graver difficulty is that the relations between Forms must belong to the realm of Forms, and those between sensible things to the realm of things. Thus men, belonging to the second, can know nothing of the true realities, the Forms. Scholars disagree over the precise interpretation of these objections. They also disagree about how Plato should have reacted to them --and about how he did react.
The Theaetetus is a discussion of the question of how knowledge should be defined. It is remarkable that the dialogue treats knowledge at length without making any reference to the Forms or to the mythology of recollection. It remains to this day one of the best introductions to the problem of knowledge. The main argument is as follows:
It seems plausible to say that knowledge is perception, which appears to imply that "What seems to me is so to me; what seems to you is so to you" (Protagoras). This relativistic doctrine is, rather oddly, claimed by Plato to be equivalent to the view held by the late 6th-century-BC Greek philosopher Heracleitus that "everything is always and in all ways in flux." But these views imply that there is no common perceived world and therefore nothing of certainty can be said or thought at all.
As for the thesis that knowledge is perception, one must first distinguish what the soul perceives through bodily organs from what it apprehends by itself without organs --such as number, sameness, likeness, being, and good. But because all knowledge involves truth and therefore being, perception, which cannot grasp being, is not identical with knowledge.
Is knowledge, then, true belief? The reference to true belief leads Plato into a discussion of false belief, for which he can discover no satisfactory analysis. False belief is belief in what is not, and what is not cannot be believed. But the example of verdicts in the law courts is enough to show that there can be true belief without knowledge.
Finally, is knowledge true belief together with an "account"? The concept of an account (logos) is not a simple one. No satisfactory definition of knowledge emerges, and the dialogue ends without a conclusion.
Because Plato's argument nowhere appeals to his favourite doctrine of Forms and because the dialogue ends so inconclusively, some scholars have suggested that Plato wanted to show that the problem of knowledge is insoluble without the Forms.
The later dialogues
Formally the important dialogues the Sophist and the Statesman are closely connected, both being ostensibly concerned with a problem of definition. The real purpose of the Sophist, however, is logical or metaphysical; it aims at explaining the true nature of negative predication, or denials that something is so. The object of the Statesman, on the other hand, is to consider the respective merits of two contrasting forms of government, personal rule and constitutionalism, and to recommend the second, particularly in the form of limited monarchy. The Sophist thus lays the foundations of all subsequent logic, the Statesman those of all constitutionalism. A second purpose in both dialogues is to illustrate the value of careful classification as a basis for scientific definition.
The Sophist purports to investigate what a Sophist really is. The definitions all lead to such notions as falsity, illusion, nonbeing. But these notions are puzzling. How can there be such a thing as a false statement or a false impression? For the false means "what is not," and what is not is nothing at all and can neither be uttered nor thought. Plato argues that what is not in some sense also is, and that what is in some sense is not; and he refutes Parmenidean monism by drawing the distinction between absolute and relative nonbeing. A significant denial, A is not B, does not mean that A is nothing, but that A is other than B; every one of the "greatest kinds," or most general, features of reality --being, identity, difference, motion, and rest-- is other than every other feature. Motion, say, is other than rest; and thus motion is not rest --but it does not follow that motion is not. The true business of dialectic is to treat the Forms themselves as an interrelated system, with relations of compatibility and incompatibility among themselves.
In the Statesman the conclusion is reached that government by a benevolent dictator is not suitable to the conditions of human life because his direction is not that of a god. The surrogate for direction by a god is the impersonal supremacy of inviolable law. Where there is such law, monarchy is the best and democracy the least satisfactory form of constitution; but where there is no law, this situation is inverted.
The Philebus contains Plato's ripest moral psychology. Its subject is strictly ethical --the question of whether the Good is to be identified with pleasure or with wisdom. Under the guidance of Socrates a mediating conclusion is reached: the best life contains both elements, but wisdom predominates.
Philosophically most important is a classification adopted to determine the formal character of the two claimants to recognition as the Good. Everything real belongs to one of four classes:
(1) the infinite or unbounded,
(2) the limit,
(3) the mixture (of infinite and limit),
(4) the cause of the mixture.
It emerges that all of the good things of life belong to the third class, that is, are produced by imposing a definite limit upon an indeterminate continuum.
The Timaeus is an exposition of cosmology, physics, and biology. Timaeus first draws the distinction between eternal being and temporal becoming and insists that it is only of the former that one can have exact and final knowledge. The visible, mutable world had a beginning; it is the work of God, who had its Forms before him as eternal models in terms of which he molded the world as an imitation. God first formed its soul out of three constituents: identity, difference, being. The world soul was placed in the circles of the heavenly bodies, and the circles were animated with movements. Subsequently the various subordinate gods and the immortal and rational element in the human soul were formed. The human body and the lower components of its soul were generated through the intermediacy of the "created gods" (i.e., the stars).
The Timaeus combines the geometry of the Pythagoreans with the biology of Empedocles by a mathematical construction of the elements, in which four of the regular solids --cube, tetrahedron, octahedron, and icosahedron-- are assumed to be the shapes of the corpuscles of earth, fire, air, and water. (The fifth, the dodecahedron, comprises the model for the whole universe.)
Among the important features of the dialogue are its introduction of God as the "demiurge" --the intelligent cause of all order and structure in the world of becoming-- and the emphatic recognition of the essentially tentative character of natural science. It is also noteworthy that, though Plato presents a corpuscular physics, his metaphysical substrate is not matter but chora (space). The presence of space as a factor requires the recognition, over and above God or mind, of an element that he called ananghe (necessity). The activity of the demiurge ensures that the universe is in general rational and well-ordered, but the brute force of material necessity sets limits to the scope and efficacy of reason. The details of Plato's cosmology, physiology, and psychophysics are of great importance for the history of science but metaphysically of secondary interest.
The Laws, Plato's longest and most intensely practical work, contains his ripest utterances on ethics, education, and jurisprudence, as well as his one entirely nonmythical exposition of theology. The immediate object is to provide a model of constitution making and legislation to assist in the actual founding of cities. The problem of the dialogue is thus not the construction of an ideal state as in the Republic but the framing of a constitution and code that might be successfully adopted by a society of average Greeks. Hence the demands made on average human nature, though exacting, are not pitched too high; and the communism of the Republic is dropped.
Purely speculative philosophy and science are excluded from the purview of the Laws, and the metaphysical interest is introduced only so far as to provide a basis for a moral theology. In compensation the dialogue is exceptionally rich in political and legal thought and appears, indirectly, to have left its mark on the great system of Roman jurisprudence.
In the ethics of the Laws Plato is rigid and rigorous --for example, homosexuality shall be completely suppressed and monogamous marriage with strict chastity shall be the rule. (In the Republic the guardian class enters into temporary unions or "sacred marriages," with a community of wives and children, to foster a concern for the common good.) In politics, Plato favours a mixed constitution, one with elements of democratic freedom and autocratic authoritarianism, and he suggests a system for securing both genuine popular representation and the proper degree of attention to personal qualifications. The basis of society is to be agriculture, not commerce. What amounts to a tax of 100 percent is to be levied on incomes beyond the statutory limits. Education is regarded as the most important of all the functions of government. The distinction between the sexes is to be treated as irrelevant.
Careful attention is to be paid to the right utilization of the child's instinct for play and to the demand that the young shall be taught in institutions where expert instruction in all of the various subjects is coordinated. Members of the supreme council of the state shall be thoroughly trained in the supreme science, which "sees the one in the many and the many in the one"; i.e., in dialectic. In the Laws Plato instituted regulations which would ensure that trials for serious offenses would take place before a court of highly qualified magistrates and would proceed with due deliberation. Also, provision was made for appeals, and a foundation was laid for a distinction between civil and criminal law.
The Laws also creates a natural theology. There are three false beliefs, Plato holds, that are fatal to moral character: atheism, denial of the moral government of the world, and the belief that divine judgment can be bought off by offerings. Plato claims that he can disprove them all. His refutation of atheism turns on the identification of the soul with the "movement which can move itself." Thus all motion throughout the universe is ultimately initiated by souls. It is then inferred from the regular character of the great cosmic motions and their systematic unity that the souls which originate them form a hierarchy with a best soul, God, at their head. Since some motions are disorderly, there must be one soul that is not the best, and there may be more. (There is no suggestion, however, that there is a worst soul, a devil.) The other two heresies can be similarly disposed of. Plato thus becomes the originator of the view that there are certain theological truths that can be strictly demonstrated by reason; i.e., of philosophical theology. Plato goes on to enact that the denial of any of his three propositions shall be a grave crime.
The Laws strikes many readers as a dull and depressing work. Its prose lacks the sparkle of the early dialogues; and Socrates, the hero of those works, would not have been tolerated under a government of the repressively authoritarian style that the Laws recommends.
(J.B.) (Ed.) (C) 2000 Britannica.com Inc