Plato (427-347 bc)

1. Life
2. Writings
3. Authenticity and chronology
4. The Platonic dialogue
5. The problem of writing
6. Early works
7. Apologetic writings
8. Laches and Charmides
9. Other dialogues of inquiry
10. The introduction of Platonism
11. Meno
12. Symposium
13. Phaedo
14. Republic
15. Critical dialogues
16. Later dialogues
17. Laws
18. Plato's influence

Evidence about Plato's life is prima facie plentiful. As well as several ancient biographies, notably that contained in book III of Diogenes Laertius' Lives of the Philosophers, we possess a collection of thirteen letters which purport to have been written by Plato. Unfortunately the biographies present what has been aptly characterized as 'a medley of anecdotes, reverential, malicious, or frivolous, but always piquant'. As for the letters, no scholar thinks them all authentic, and some judge that none are.

From the biographies it is safe enough to accept some salient points. Plato was born of an aristocratic Athenian family. He was brother to Glaucon and Adimantus, Socrates' main interlocutors in the Republic; his relatives included Critias and Charmides, members of the bloody junta which seized power in Athens at the end of the Peloponnesian War. He became one of the followers of Socrates, after whose execution he withdrew with others among them to the neighbouring city of Megara. His travels included a visit to the court of Dionysius in Sicily. On returning from Sicily to Athens he began teaching in a gymnasium outside the city, called the Academy.

The Seventh Letter, longest and most interesting of the collection of letters, gives a good deal of probably trustworthy information, whether or not it was written by Plato himself. It begins with an account of his growing disenchantment with Athenian politics in early manhood and of his decision against a political career. This is prefatory to a sketch of the visit to Dionysius in Syracuse, which is followed by an elaborate self-justifying explanation of why and how, despite his decision, Plato later became entangled in political intrigue in Sicily, once the young Dionysius II had succeeded to his father's throne. There were two separate visits to the younger Dionysius: one (c.366 bc) is represented as undertaken at the behest of Dion, nephew of Dionysius I, in the hope of converting him into a philosopher-ruler; the other (c.360 bc) was according to the author an attempt to mediate between Dionysius and Dion, now in exile and out of favour. Both ventures were humiliating failures.

Of more interest for the history of philosophy is Plato's activity in the Academy. We should not conceive, as scholars once did, that he established a formal philosophical school, with its own property and institutional structures. Although he acquired a house and garden in the vicinity, where communal meals were probably taken, much of his philosophical teaching and conversation may well have been conducted in the public space of the gymnasium itself. Some sense of the Academy's distinctive style may be gleaned from evidence of the contemporaneous writings of the philosophical associates he attracted, notably his nephew Speusippus, Xenocrates, Aristotle and the mathematician Eudoxus. Discussion of Plato's metaphysical ideas figured prominently in these; but orthodoxy was not expected, to judge from their philosophical disagreements with him and with each other. Aristotle's early Topics suggests that an important role was played by formal disputation about philosophical theses.

From the educational programme of the Republic one might have guessed that Plato would have attached importance to the teaching of mathematics as a preparation for philosophy, but we have better evidence for his encouraging research in it. While he was not an original mathematician himself, good sources tell us that he formulated problems for others to solve: for example, what uniform motions will account for the apparent behaviour of the planets. Otherwise there is little reliable information on what was taught in the Academy: not much can be inferred from the burlesque of comic playwrights. Since almost certainly no fees were charged, most of those who came to listen to Plato (from all over the Greek world) must have been aristocrats. Some are known to have entered politics or to have advised princes, particularly on constitutional reform. But the Academy had no political mission of its own. Indeed the rhetorician Isocrates, head of a rival school and admittedly not an unbiased witness, dismissed the abstract disciplines favoured by the Academy for their uselessness in the real world.

Thrasyllus, astrologer to the emperor Tiberius, is the unlikely source of the arrangement of Platonic writings adopted in the manuscript tradition which preserves them. For his edition of Plato he grouped them into tetralogies, reminiscent of the trilogies produced in Athenian tragic theatre. These were organized according to an architectonic scheme constructed on principles that are now only partially apparent, but certainly had nothing to do with chronology of composition. His arrangement began with a quartet 'designed to show what the life of the philosopher is like' (Diogenes Laertius, III 57): Euthyphro, or 'On Piety', classified as a 'peirastic' or elenctic dialogue (see Socrates ��3-4), which is a species of one of his two main genres, the dialogue of inquiry; Apology, Crito and Phaedo are all regarded as specimens of exposition, his other main genre, or more specifically as specimens of ethics. These four works are all concerned in one way or another with the trial and death of Socrates.

There followed a group consisting of Cratylus, or 'On the Correctness of Names', Theaetetus, or 'On Knowledge', Sophist and Politicus (often Anglicized as Statesman). Plato himself indicates that the last three of this set are to be read together. They contain some of his most mature and challenging work in epistemology, metaphysics and philosophical methodology. In this they resemble Parmenides, with its famous critique of the theory of Forms, the first of the next tetralogy, which was completed by three major dialogues all reckoned 'ethical' by Thrasyllus: Philebus, an examination of pleasure, Symposium and Phaedrus, both brilliant literary divertissements which explore the nature of love.

A much slighter quartet came next: two dialogues entitled Alcibiades, plus Hipparchus and Rivals. None of these, with the disputed exception of the first Alcibiades, is thought by modern scholarship to be authentic Plato. They were followed by Theages, a short piece now generally reckoned spurious, Charmides, Laches, Lysis. These three works are generally regarded by modern scholars as Socratic dialogues: that is, designed to exhibit the distinctive method and ethical preoccupations of the historical Socrates, at least as Plato understood him, not to develop Plato's own philosophy. Thrasyllus would agree with the latter point, since he made them dialogues of inquiry: Laches and Lysis 'maieutic', in which the character 'Socrates' attempts as intellectual midwife to assist his interlocutors to articulate and work out their own ideas on courage and friendship respectively; Charmides elenctic, with the interlocutors Charmides and Critias and their attempts to say what moderation is put to the test of cross-examination, something Thrasyllus interestingly distinguished from philosophical midwifery.

The next group consisted of Euthydemus, Protagoras, Gorgias, Meno, important works in which modern scholarship finds analysis and further elaboration by Plato of the Socratic conception of virtue. The first three present a Socrates in argumentative conflict with sophists of different sorts (see Sophists), so it is understandable that under the general heading 'competitive' Thrasyllus characterized Euthydemus and Gorgias as dialogues of refutation, and Protagoras as a dialogue of display - presumably because Protagoras and Socrates are each portrayed as intent on showing off their debating skills. Meno, on the other hand, is labelled an elenctic work. It was followed by the seventh tetralogy: Hippias Major and Hippias Minor, two very different dialogues (of refutation, according to Thrasyllus), both featuring the sophist of that name; Ion, a curious piece on poetic performance; and Menexenus, a still more curious parody of a funeral oration, put in the mouth of Pericles' mistress Aspasia.

For the last two tetralogies Thrasyllus reserved some of Plato's major writings. The eighth contained the very brief (and conceivably spurious) Clitophon, in which a minor character from the Republic plays variations on themes in the Republic, the second dialogue in the group, and generally regarded nowadays as Plato's greatest work. This quartet was completed by Timaeus and its unfinished sequel Critias, no doubt because these dialogues represent themselves as pursuing further the discussions of the Republic. The pre-Copernican mathematical cosmology of Timaeus no longer attracts readers as it did throughout antiquity, and particularly in the Middle Ages, when the dialogue was for a period the only part of Plato's uvre known to the Latin West. Finally, the ninth tetralogy began with the short Minos, a spurious dialogue taking up issues in the massive Laws, Plato's longest and probably latest work, which was put next in the group. Then followed Epinomis, an appendix to Laws already attributed to one of Plato's pupils in antiquity (Philip of Opous, according to a report in Diogenes Laertius, III 37). Last were placed the Letters, briefly discussed above.

Thrasyllus rejected from the canon a variety of minor pieces, some of which still survive through the manuscript tradition. Modern judgment concurs with the ancient verdict against them. It also questions or rejects some he thought genuinely Platonic. But we can be fairly sure that we still possess everything Plato wrote for publication.

Attempting to determine the authenticity or inauthenticity of ancient writings is a hazardous business. Egregious historical errors or anachronisms suffice to condemn a work, but except perhaps for the Eighth Letter, this criterion gets no purchase on the Platonic corpus. Stylistic analysis of various kinds can show a piece of writing to be untypical of an author's uvre, without thereby demonstrating its inauthenticity: Parmenides is a notable example of this. Most of Plato's major dialogues are in fact attested as his by Aristotle. The difficult cases are short pieces such as Theages and Clitophon, and, most interestingly, three more extended works: the Seventh Letter, Alcibiades I and Hippias Major. Opinion remains divided on them. Some scholars detect crude or sometimes brilliant pastiche of Plato's style; a parasitic relationship with undoubtedly genuine dialogues; a philosophical crassness or a misunderstanding of Platonic positions which betrays the forger's hand. Yet why should Plato not for some particular purpose recapitulate or elaborate things he has said elsewhere? And perhaps he did sometimes write more coarsely or didactically or long-windedly than usual. Such assessments are inevitably matters of judgment, on which intelligent and informed readers will legitimately differ.

Prospects for an absolute chronology of Plato's writings are dim. There are no more than two or three references to datable contemporaneous events in the entire corpus (leaving aside the Letters). Relative chronology is another matter. Some dialogues refer back to others. A number of instances have been mentioned already, but we can add a clear reminiscence of Meno in Phaedo (72e-73b), and of Parmenides in both Theaetetus (183e-184a) and Sophist (217c). According to one ancient tradition Laws was unfinished at Plato's death, and Aristotle informs us that it was written after Republic (Politics 1264b24- 7), to which it appears to allude (see, for example, Laws 739a-e). Attempts have sometimes been made to find evidence, whether internal or external, for the existence of early versions of works we possess in different form (see for example Thesleff 1982). One example is the suggestion that Aristophanes' comedy Ecclesiazousae or Assembly of Women (388 bc) was parodying an early version of book V of Republic. But while the idea that Plato may have revised some of his writings is plausible, concrete instances in which such revision is plainly the best explanation of the phenomena are hard to find. Even if they were not, it is unlikely that the consequences for relative chronology would be clear.

For over a century hopes for a general relative chronology of Plato's writings have been pinned on the practice of stylistic analysis. This was pioneered by Lewis Campbell in his edition of Sophist and Politicus, published in 1867. His great achievement was to isolate a group of dialogues which have in common a number of features (added to by subsequent investigators) that set them apart from all the rest. Timaeus, Critias, Sophist, Politicus, Philebus and Laws turn out to share among other things a common technical vocabulary; a preference for certain particles, conjunctions, adverbs and other qualifiers over alternatives favoured in other dialogues; distinctive prose rhythms; and the deliberate attempt to avoid the combination of a vowel at the end of one word followed by another vowel at the beginning of the next. Since there are good independent reasons for taking Laws to be Plato's last work, Campbell's sextet is very likely the product of his latest phase of philosophical activity. Application of the same stylistic tests to the Platonic corpus as a whole, notably by Constantin Ritter (1888), established Republic, Theaetetus and Phaedrus as dialogues which show significantly more of the features most strongly represented in the late sextet than any others. There is general agreement that they must be among the works whose composition immediately precedes that of the Laws group, always allowing that Republic must have taken several years to finish, and that parts of it may have been written earlier and subsequently revised. Parmenides is ordinarily included with these three, although mostly on non-stylistic grounds.

Since Campbell's time there have been repeated attempts by stylometrists to divide the remaining dialogues into groups, and to establish sequences within groups. The heyday of this activity was in the late nineteenth and early twentieth centuries. Since the 1950s there has been a revival in stylistic study, with the use of increasingly sophisticated statistical techniques and the resources of the computer and the database. Secure results have proved elusive. Most scholars would be happy to date Phaedo, Symposium and Cratylus to a middle period of Plato's literary and philosophical work which may be regarded as achieving its culmination in Republic. But while this dating is sometimes supported by appeal to stylistic evidence, that evidence is in truth indecisive: the hypothesis of a middle period group of dialogues really rests on their philosophical affinities with Republic and their general literary character. The same can be said mutatis mutandis of attempts to identify a group assigned to Plato's early period.

The cohesiveness of Campbell's late group has not gone unchallenged. For example, in 1953 G.E.L. Owen mounted what for a while seemed to some a successful attack on his dating of Timaeus and Critias, on the ground that these dialogues belong philosophically in Plato's middle period. Broadly speaking, however, stylistic studies have helped to establish an agreed chronological framework within which most debates about philosophical interpretation now take place. This is not to say however that there is unanimity either about the way Plato's thought developed or about the importance of the notion of development for understanding his philosophical project or projects in the dialogues.

Who invented the philosophical dialogue, and what literary models might have inspired the invention, are not matters on which we have solid information. We do know that several of Socrates' followers composed what Aristotle calls Sokratikoi logoi, discourses portraying Socrates in fictitious conversations (see Socratic dialogues). The only examples which survive intact besides Plato's are by Xenophon, probably not one of the earliest practitioners of the genre.

One major reason for the production of this literature was the desire to defend Socrates against the charges of irreligion and corrupting young people made at his trial and subsequently in Athenian pamphleteering, as well as the implicit charge of guilt by association with a succession of oligarchic politicians. Thus his devotion to the unstable and treacherous Alcibiades was variously portrayed in, for example, the first of the Alcibiades dialogues ascribed to Plato and the now fragmentary Alcibiades of Aeschines of Sphettos, but both emphasized the gulf between Alcibiades' self-conceit and resistance to education and Socrates' disinterested concern for his moral wellbeing. The same general purpose informed the publication of versions of Socrates' speech (his 'apology') before the court by Plato, Xenophon and perhaps others. Writing designed to clear Socrates' name was doubtless a particular feature of the decade or so following 399 bc, although it clearly went on long after that, as in Xenophon's Memorabilia (see Xenophon �2). After starting in a rather different vein Gorgias turns into Plato's longest and angriest dialogue of this kind. Socrates is made to present himself as the only true politician in Athens, since he is the one person who can give a truly rational account of his conduct towards others and accordingly command the requisite political skill, which is to make the citizens good. But he foresees no chance of acquittal by a court of jurors seeking only gratification from their leaders.

Placing Socrates in opposition to Alcibiades is a way of defending him. Arranging a confrontation between a sophist (Protagoras or Hippias) or a rhetorician (Gorgias) or a religious expert (Euthyphro) or a Homeric recitalist (Ion) and Socrates is a way of exposing their intellectual pretensions, and in most cases their moral shallowness, while celebrating his wit, irony and penetration and permitting his distinctive ethical positions and ethical method to unfold before the reader's eyes. The elenchus (see Socrates ��3-4) is by no means the only mode of argument Socrates is represented as using in these fictional encounters. Plato particularly enjoys allowing him to exploit the various rhetorical forms favoured by his interlocutors. But it is easy to see why the dialogue must have seemed to Plato the ideal instrument not only for commemorating like Xenophon Socrates' style of conversation, but more importantly for exhibiting the logical structure and dynamic of the elenchus, and its power in Socrates' hands to demolish the characteristic intellectual postures of those against whom it is deployed.

In these dialogues of confrontation Socrates seldom succeeds in humbling his interlocutors into a frank recognition that they do not know what they thought they knew: the official purpose - simultaneously intellectual and moral - of the elenchus. It would not have been convincing to have him begin to convert historical figures with well-known intellectual positions. The main thing registered by their fictional counterparts is a sense of being manipulated into self-contradiction. In any case, the constructive response to the extraordinary figure of Socrates which Plato really wants to elicit is that of the reader. We have to suppose that, as conversion to philosophy was for Plato scarcely distinguishable from his response to Socrates (devotion to the man, surrender to the spell of his charisma, strenuous intellectual engagement with his thought and the questions he was constantly pursuing), so he conceived that the point of writing philosophy must be to make Socrates charismatic for his readers - to move us to similar devotion and enterprise. In short, the dialogues constitute simultaneously an invitation to philosophy and a critique of its intellectual rivals.

Whatever Plato's other accomplishments or failures as a writer and thinker, one project in which he unquestionably succeeds is in creating a Socrates who gets under the reader's skin (see Socrates �7). Plato has a genius for portrayal of character: the 'arrogant self-effacement' of Socrates' persona; the irony at once sincere and insincere; the intellectual slipperiness in service of moral paradox; the nobility of the martyr who loses everything but saves his own soul, and of the hero who stands firm on the battlefield or in face of threats by the authorities; relentless rationality and almost impregnable self-control somehow cohabiting with susceptibility to beautiful young men and their erotic charm. Also important is the ingenious variety of perspectives from which we see Socrates talking and interacting with others. Sometimes he is made to speak to us direct (for example, Apology, Gorgias). Sometimes Plato invites us to share complicity in a knowing narrative Socrates tells of his own performance (as in Charmides, Protagoras). Sometimes someone else is represented as recalling an unforgettably emotional occasion when Socrates dominated a whole roomful of people, as in the most powerfully dramatic dialogues of all, Phaedo and Symposium. Here we have the illusion that Socrates somehow remains himself even though the ideas advanced in them must go beyond anything that the historical Socrates (or at any rate the agnostic Socrates of Apology) would have claimed about the soul and its immortality or about the good and the beautiful.

It might seem strange that an original philosopher of Plato's power and stature should be content, outside the Letters if some of them are by him, never to talk directly to the reader, but only through the medium of narrative or dramatic fiction, even granted the pleasure he plainly takes in exhibiting his mastery of that medium. This will become less mysterious if we reflect further on Socrates and Socratic questioning. At any rate by the time of the Meno, Plato was wanting to suggest that the elenchus presupposes that understanding is not something one person can transmit in any straightforward way to another, but something which has to be worked out for oneself and recovered from within by recollection. The suggestion is made by means of an example from mathematics, where it is transparently true that seeing the answer to a problem is something that nobody else can do for us, even if Socrates' questions can prompt us to it. The moral we are to draw is that in pressing his interlocutors on what they say they believe, Socrates is merely an intellectual midwife assisting them to articulate for themselves a more coherent and deeply considered set of views, which will ideally constitute the truth.

The Platonic dialogue can be interpreted as an attempt to create a relationship between author and reader analogous to that between Socrates and his interlocutors. Given that that relationship is to be construed in the way indicated in Meno, the point of a dialogue will be like that of the elenchus: not to teach readers the truth (it is strictly speaking unteachable), but to provoke and guide them into working at discovering it for themselves. Most of the dialogues of Campbell's late sextet are admittedly more didactic than one would expect on this view of the dialogue, and it is significant that except in Philebus Socrates is no longer the main speaker. Yet even here use of the dialogue form can be taken as symbolizing that responsibility for an active philosophical engagement with what Plato has written rests with the reader, as the difficulty and in some cases the methodological preoccupations of most of these works confirms.

In a much discussed passage at the end of Phaedrus (275-8), Socrates is made to speak of the limitations of the written word. It can answer no questions, it cannot choose its readers, it gets misunderstood with no means of correcting misunderstanding. Its one worthwhile function is to remind those who know of what they know. By contrast with this dead discourse live speech can defend itself, and will be uttered or not as appropriate to the potential audience. The only serious use of words is achieved when speech, not writing, is employed by dialecticians to sow seeds of knowledge in the soul of the learner. If they commit their thoughts to writing they do so as play (paidia). The Seventh Letter (341-2) makes related remarks about the writing of philosophy; and at various points in, for example, Republic, Timaeus and Laws, the discussions in which the interlocutors are engaged are described as play, not to be taken seriously.

Interpreters have often taken these written remarks about writing with the utmost seriousness. In particular the T�bingen school of Platonic scholarship has connected them with references, especially in Aristotle, to unwritten doctrines of Plato. They have proposed that the fundamental principles of his philosophy are not worked out in the dialogues at all, but were reserved for oral discussions in the Academy, and have to be reconstructed by us from evidence about the unwritten doctrines. But this evidence is suspect where voluble and elusive when apparently more reliable. There are two star exhibits. First, according to the fourth century bc music theorist Aristoxenus, Aristotle used to tell of how when Plato lectured on the good he surprised and disappointed his listeners by talking mostly about mathematics (Harmonics II, 30.16-31.3). Second, at one point in the Physics (209b13-6) Aristotle refers to Plato's 'so-called unwritten teachings'; and the Aristotelian commentators report that Aristotle and other members of the Academy elsewhere wrote more about them. Plato's key idea was taken to be the postulation of the One and the great and the small, or 'indefinite dyad' as principles of all things, including Forms. In his Metaphysics (I.6) Aristotle seems to imply that in this theory the Forms were construed in some sense as numbers. It remains obscure and a subject of inconclusive scholarly debate how far the theory was worked out, and what weight we should attach to it in comparison to the metaphysical explorations of the dialogues of Plato's middle and late periods (see for example Ross 1951, Gaiser 1968, Guthrie 1978, Gaiser 1980, Burnyeat 1987).

The general issue of how far we can ascribe to Plato things said by interlocutors (principally Socrates) in his dialogues is something which exercises many readers. The position taken in this entry will be that no single or simple view of the matter is tenable: sometimes, for example, Plato uses the dialogue form to work through a problem which is vexing him; sometimes to recommend a set of ideas to us; sometimes to play teasingly with ideas or positions or methodologies without implying much in the way of commitment; and frequently to suggest to us ways we should or should not ourselves try to philosophize. As for the T�bingen school, we may agree with them that when it introduces the Form of the Good the Republic itself indicates that readers are being offered only conjectures and images, not the thorough dialectical discussion necessary for proper understanding. But the notions of seriousness and play are less straightforward than they allow. Playing with ideas - that is, trying them out and developing them to see what might work and what will not - is the way new insights in philosophy and science are often discovered. When we meet it in Plato's dialogues it usually seems fun without being frivolous. Nor should we forget that the Platonic dialogue represents itself as a spoken conversation. It seems hard to resist the thought that we are thereby invited to treat his dialogues not as writing so much as an attempt to transcend the limitations of writing. Perhaps the idea is that they can achieve the success of living speech if treated not as texts to be interpreted (despite Plato's irresistible urge to produce texts devised precisely to elicit attempts at interpretation), but as stimuli to questions we must put principally to ourselves, or as seeds which may one day grow into philosophy in our souls.

There is widespread scholarly agreement that the following are among Plato's earliest writings: Apology, Crito, Ion, Hippias Minor, Laches and Charmides. Apology, as we have noted, best fits into the context of the decade following Socrates' death, and so does Crito, which explores the question why he did not try to escape from the condemned cell; the others are all short treatments of questions to do with virtue and knowledge, or in the case of Ion, with expertise (techn), and all are relatively simple in literary structure. The brief Euthyphro and the much longer Protagoras and Gorgias (with which Menexenus is often associated) are usually seen as having many affinities with these, and so are put at least fairly early, although here anticipations of the style or content of the mature middle-period dialogues have also been detected. The connections in thought between Lysis, Euthydemus and Hippias Major and middle-period Plato may be argued to be stronger still, even though there remain clear similarities with the dialogues generally accepted as early. We do not know whether Plato wrote or published anything before Socrates' death; Menexenus cannot be earlier than 386 bc, Ion might be datable to around 394-391 bc, but otherwise we can only guess.

All those listed above fall under the commonly used description 'Socratic dialogues', because they are seen as preoccupied with the thought of the historical Socrates as Plato understood him, in contrast with writings of the middle period, where 'Socrates' often seems to become a vehicle for exploring a more wide-ranging set of ideas (see Socrates �2). In the Socratic dialogues discussion is confined almost exclusively to ethical questions, or problems about the scope and credentials of expertise: metaphysics and epistemology and speculation about the nature and powers of the soul are for the most part notable by their absence. Use of the elenchus is prominent in them as it is not, for example, in Republic (apart from book I, sometimes regarded as an early work subsequently reused as a preface to the main body of the dialogue). The hypothesis that philosophizing in this style was the hallmark of the historical Socrates is broadly consistent with what we are given to understand about him by Xenophon, Aristotle and Plato's Apology - which is usually thought to be particularly authoritative evidence, whether or not it is a faithful representation of what Socrates really said at his trial.

How historical the historical Socrates of the hypothesis actually is we shall never know. The conjecture that many of the Socratic dialogues are early works is likewise only a guess, which gets no secure support from stylometric evidence. None the less the story of Plato's literary and philosophical development to which it points makes such excellent sense that it has effectively driven all rival theories from the field. The placing of individual dialogues within that story remains a matter for controversy; and doubts persist over how far interpretation of Plato is illuminated or obstructed by acceptance of any developmental pattern. With these provisos, the account which follows assumes the existence of a group of early Socratic dialogues in the sense explained.

The convenience of the description 'Socratic dialogues' should not generate the expectation of a single literary or philosophical enterprise in these writings. It conceals considerable variety, for example as between works devoted to articulating and defending the philosophical life and works which problematize Socratic thought as much as they exhibit its attractions. This distinction is not an exhaustive one, but provides useful categories for thinking about some of the key productions of Plato's early period.

Moral, or indeed existential, choice, to use an anachronistic expression, is the insistent focus of Apology. God has appointed Socrates, as he represents it to his judges, to live the philosophical life, putting himself and others under constant examination. The consistency of his commitment to this mission requires him now to face death rather than abandon his practice of philosophy, as he supposes for the sake of argument the court might require him to do. For confronted with the choice between disobeying God (that is, giving up philosophy) and disobeying human dictate (that is, refusing to do so), he can only take the latter option. What governs his choice is justice:

It is a mistake to think that a man worth anything at all should make petty calculations about the risk of living or dying. There is only one thing for him to consider when he acts: whether he is doing right or wrong, whether he is doing what a good man or a bad man would do.

(Apology 28b)

Whether death is or is not a bad thing Socrates says he does not know. He does know that behaving wrongly and disobeying one's moral superior - whether divine or human - is bad and shameful. The demands of justice, as his conscience (or 'divine sign') interpreted them, had earlier led him to choose the life of a private citizen, conversing only with individuals, rather than the political life: for justice and survival in politics are incompatible. When he did carry out the public obligations of a citizen and temporarily held office, justice again compelled him to choose the dangerous and unpopular course of resisting a proposal that was politically expedient but contrary to the law. As for those with whom he talked philosophy, they too faced a choice: whether to make their main concern possessions and the body, or virtue and the soul; that is, what belongs to oneself, or oneself. And now the judges too must choose and determine what is just as their oath requires of them.

Crito and Gorgias continue the theme in different ways. Crito has often been found difficult to reconcile with Apology when it argues on various grounds (paternalistic and quasi-contractual) that citizens must always obey the law, unless they can persuade it that it is in the wrong. Hence, since the law requires that Socrates submit to the punishment prescribed by the court, he must accept the sentence of death pronounced on him. The higher authority of divine command stressed in Apology seems to have been forgotten. Once again, however, the whole argument turns on appeal to justice and to the choices it dictates: we must heed the truth about it, not what popular opinion says; we must decide whether or not we believe the radical Socratic proposition that retaliation against injury or injustice is never right (see Socrates �4). Gorgias, one of the longest of all the dialogues, ranges over a wide territory, but at its heart is the presentation of a choice. Socrates addresses Callicles, in whose rhetoric Nietzsche saw an anticipation of his ideal of the superman:

You see that the subject of our arguments - and on what subject should a person of even small intelligence be more serious? - is this: what kind of life should we live? The life which you are now urging upon me, behaving as a man should: speaking in the assembly and practising rhetoric and engaging in politics in your present style? Or the life of philosophy?

(Gorgias 500c)

The dialogue devotes enormous energy to arguing that only philosophy, not rhetoric, can equip us with a true expertise which will give us real power, that is power to achieve what we want: the real not the apparent good. Only philosophy can articulate a rational and reliable conception of happiness - which turns out to depend on justice.

Contrast the works outlined in �7 with Laches and Charmides, which were very likely conceived as a pair, the one an inquiry into courage, the other into sophrosyn or moderation. Both engage in fairly elaborate scene setting quite absent from Crito and Gorgias. In both there is concern with the relation between theory and practice, which is worked out more emphatically in Laches, more elusively in Charmides. For example, in Laches Socrates is portrayed both as master of argument about courage, and as an exemplar of the virtue in action - literally by reference to his conduct in the retreat from Delium early in the Peloponnesian War, metaphorically by his persistence in dialectic, to which his observations on the need for perseverance in inquiry draw attention.

A particularly interesting feature of these dialogues is their play with duality. Socrates confronts a pair of main interlocutors who clearly fulfil complementary roles. We hear first the views of the more sympathetic members of the two pairs: the general Laches, whom Socrates identifies as his partner in argument, and the young aristocrat Charmides, to whom he is attracted. Each displays behavioural traits associated with the virtue under discussion, and each initially offers a definition in behavioural terms, later revised in favour of a dispositional analysis: courage is construed as a sort of endurance of soul, sophrosyn as modesty. After these accounts are subjected to elenchus and refuted, the other members of the pairs propose intellectualist definitions: according to Nicias (also a general), courage is knowledge of what inspires fear or confidence, while Critias identifies sophrosyn with self-knowledge.

Broad hints are given that the real author of these latter definitions is Socrates himself; and in Protagoras he is made to press Protagoras into accepting the same definition of courage. There are also hints that, as understood by their proponents here, this intellectualism is no more than sophistic cleverness, and that neither possesses the virtue he claims to understand. Both are refuted by further Socratic elenchus, and in each case the argument points to the difficulty of achieving an intellectualist account which is not effectively a definition of virtue in general as the simple knowledge of good and bad. Laches explicitly raises the methodological issue of whether one should try to investigate the parts of virtue in order to understand the whole or vice versa (here there are clear connections with the main argument of Protagoras).

Aristotle was in no doubt that Socrates 'thought all the virtues were forms of knowledge' (Eudemian Ethics 1216b6); and many moves in the early dialogues depend on the assumption that if you know what is good you will be good (see Socrates �5). But Laches and Charmides present this Socratic belief as problematical. Not only is there the problem of specifying a unique content for the knowledge with which any particular virtue is to be identified. There is also the difficulty that any purely intellectual specification of what a virtue is makes no reference to the dispositions Charmides and Laches mention and (like Socrates) exemplify. In raising this difficulty Plato is already adumbrating the need for a more complex moral psychology than Socrates', if only to do justice to how Socrates lived. If the viewpoints of Laches and Nicias are combined we are not far from the account of courage in Republic, as the virtue of the spirited part of the soul, which 'preserves through pains and pleasures the injunctions of reason concerning what is and is not fearful' (442b).

In Protagoras it is Socrates himself who works out and defends the theory that knowledge is sufficient for virtuous action and that different virtues are different forms of that knowledge (see Aret). He does not here play the role of critic of the theory, nor are there other interlocutors who might suggest alternative perceptions: indeed Protagoras, as partner not adversary in the key argument, is represented as accepting the key premise that (as he puts it) 'wisdom and knowledge are the most powerful forces governing human affairs' (352c-d). It would be a mistake to think that Plato found one and the same view problematic when he wrote Laches and Charmides but unproblematic when he wrote Protagoras, and to construct a chronological hypothesis to cope with the contradiction. Protagoras is simply a different sort of dialogue: it displays Socratic dialectic at work from a stance of some detachment, without raising questions about it. Protagoras is an entirely different kind of work from Gorgias, too: the one all urbane sparring, the latter a deadly serious confrontation between philosophy and political ambition. Gorgias unquestionably attacks hedonism, Protagoras argues for it, to obtain a suitable premise for defending the intellectualist paradox that nobody does wrong willingly, but leaves Socrates' own commitment to the premise at best ambiguous (see Socrates �6). Incommensurabilities of this kind make it unwise to attempt a relative chronology of the two dialogues on the basis of apparent incompatibilities in the positions of their two Socrates.

Space does not permit discussion of Ion, or of Hippias Minor, in which Socrates is made to tease us with the paradox - derived from his equation of virtue and knowledge - that someone who did do wrong knowingly and intentionally would be better than someone who did it unintentionally through ignorance. Interpretation of Euthyphro remains irredeemably controversial. Its logical ingenuity is admired, and the dialogue is celebrated for its invention of one of the great philosophical questions about religion: either we should do right because god tells us to do so, which robs us of moral autonomy, or because it is right god tells us to do it, which makes the will of god morally redundant.

Something more needs to be said about Lysis and Euthydemus (which share a key minor character in Ctesippus, and are heavy with the same highly charged erotic atmosphere) and Hippias Major. They all present Socrates engaging in extended question and answer sessions, although only in Hippias is this an elenchus with real bite: in the other dialogues his principal interlocutors are boys with no considered positions of their own inviting refutation. All end in total failure to achieve positive results. All make great formal play with dualities of various kinds. Unusually ingenious literary devices characterize the three works, ranging from the introduction of an alter ego for Socrates in Hippias to disruption of the argument of the main dialogue by its 'framing' dialogue in Euthydemus, at a point where the discussion is clearly either anticipating or recalling the central books of Republic. All seem to be principally preoccupied with dialectical method (admittedly a concern in every dialogue). Thus Hippias is a study in definitional procedure, applied to the case of the fine or beautiful, Lysis a study in thesis and antithesis paralleled in Plato's uvre only by Parmenides, and Euthydemus an exhibition of the contrast between 'eristic', that is, purely combative sophistical argument, demonstrated by the brothers Euthydemus and Dionysodorus, and no less playful philosophical questioning that similarly but differently ties itself in knots. It is the sole member of the trio which could be said with much conviction to engage - once more quizzically - with the thought of the historical Socrates about knowledge and virtue. But its introduction of ideas from Republic makes it hard to rank among the early writings of Plato. Similarly, in Lysis and Hippias Major there are echoes or pre-echoes of the theory of Forms and some of the causal questions associated with it. We may conclude that these ingenious philosophical exercises - 'gymnastic' pieces, to use the vocabulary of Parmenides - might well belong to Plato's middle period.

Needless to say, no explicit Platonic directive survives encouraging us to read Meno, Symposium and Phaedo together. But there are compelling reasons for believing that Plato conceived them as a group in which Meno and Symposium prepare the way for Phaedo. In brief, in Meno Plato introduces his readers to the non-Socratic theory of the immortality of the soul and a new hypothetical method of inquiry, while Symposium presents for the first time the non-Socratic idea of a Platonic Form, in the context of a notion of philosophy as desire for wisdom. It is only in Phaedo that all these new ideas are welded together into a single complex theory incorporating epistemology, psychology, metaphysics and methodology, and constituting the distinctive philosophical position known to the world as Platonism.

Meno and Symposium share two features which indicate Plato's intention that they should be seen as a pair, performing the same kind of introductory functions, despite enormous differences for example in dialogue form, scale and literary complexity. First, both are heavily and specifically foreshadowed in Protagoras, which should accordingly be reckoned one of the latest of Plato's early writings. At the end of Protagoras (361c) Socrates is made to say that he would like to follow up the inconclusive conversation of the dialogue with another attempt to define what virtue is, and to consider again whether or not it can be taught. This is exactly the task undertaken in Meno. Similarly, not only are all the dramatis personae of Symposium except Aristophanes already assembled in Protagoras, but at one point Socrates is represented as offering the company some marginally relevant advice on how to conduct a drinking party - which corresponds exactly to what happens at the party in Symposium (347c-348a).

Second, both Meno and Symposium are exceedingly careful not to make Socrates himself a committed proponent either of the immortality of the soul or of the theory of Forms. These doctrines are ascribed respectively to 'priests and priestesses' (Meno) and to one priestess, Diotima, in particular (Symposium); in Meno Socrates says he will not vouch for the truth of the doctrine of immortality, in Symposium he records Diotima's doubts as to whether he is capable of initiation into the mysteries (a metaphor also used of mathematics in Meno) which culminate in a vision of the Form of the Beautiful. In Symposium these warning signs are reinforced by the extraordinary form of the dialogue: the sequence of conversations and speeches it purports to record are nested inside a Chinese box of framing conversations, represented as occurring some years later and with participants who confess to inexact memory of what they heard.

Phaedo for its part presupposes Meno and Symposium. At 72e-73b Meno's argument for the immortality of the soul is explicitly recalled, while the Form of Beauty is regularly mentioned at the head of the lists of the 'much talked about' Forms which Phaedo introduces from time to time (for example, 75c, 77a, 100b). It is as though Plato relies upon our memory of the much fuller characterization of what it is to be a Form supplied in Symposium. Unlike Meno and Symposium, Phaedo represents Socrates himself as committed to Platonist positions, but takes advantage of the dramatic context - a discussion with friends as he waits for the hemlock to take effect - and makes him claim prophetic knowledge for himself like a dying swan (84e-85b). The suggestion is presumably that Platonism is a natural development of Socrates' philosophy even if it goes far beyond ideas about knowledge and virtue and the imperatives of the philosophical life to which he is restricted in the early dialogues.

Meno is a dialogue of the simplest form and structure. It consists of a conversation between Socrates and Meno, a young Thessalian nobleman under the spell of the rhetorician Gorgias, interrupted only by a passage in which Socrates quizzes Meno's slave, and then later by a brief intervention in the proceedings on the part of Anytus, Meno's host and one of Socrates' accusers at his trial. The dialogue divides into three sections: an unsuccessful attempt to define what virtue is, which makes the formal requirements of a good definition its chief focus; a demonstration in the face of Meno's doubts that successful inquiry is none the less possible in principle; and an investigation into the secondary question of whether virtue can be taught, pursued initially by use of a method of hypothesis borrowed from mathematics. Although the ethical subject matter of the discussion is thoroughly Socratic, the character and extent of its preoccupation with methodology and (in the second section) epistemology and psychology are not. Nor is Meno's use of mathematical procedures to cast light on philosophical method; this is not confined to the third section. Definitions of the mathematical notion of shape are used in the first section to illustrate for example the principle that a definition should be couched in terms that the interlocutor agrees are already known. And the demonstration of an elenchus with a positive outcome which occupies the second is achieved with a geometrical example.

It looks as though Plato has come to see in the analogy with mathematics hope for more constructive results in philosophy than the Socratic elenchus generally achieved in earlier dialogues. This is a moral which the second and third sections of Meno make particularly inviting to draw. In the second Socrates is represented as setting Meno's untutored slave boy a geometrical problem (to determine the length of the side of a square twice the size of a given square) and scrutinizing his answers by the usual elenctic method. The boy begins by thinking he has the answer. After a couple of mistaken attempts at it he is persuaded of his ignorance. So far so Socratic. But then with the help of a further construction he works out the right answer, and so achieves true opinion, which it is suggested could be converted into knowledge if he were to go through the exercise often. The tacit implication is that if elenchus can reach a successful outcome in mathematics, it ought to be capable of it in ethics too.

None the less direct engagement with the original problem of what virtue is is abandoned, and the discussion turns to the issue of its teachability, and to the method of hypothesis. Here the idea is that instead of investigating the truth of proposition p directly 'you hit upon another proposition h ('the hypothesis'), such that p is true if and only if h is true, and then investigate the truth of h, undertaking to determine what would follow (quite apart from p) if h were true and, alternatively, if it were false' (Gregory Vlastos' formulation (1991)). After illustrating this procedure with an exceedingly obscure geometrical example, Socrates makes a lucid application of it to the ethical problem before them, and offers the Socratic thesis that virtue is knowledge as the hypothesis from which the teachability of virtue can be derived. The subsequent examination of this hypothesis comes to conclusions commentators have found frustratingly ambiguous. But the survival and development of the hypothetical method in Phaedo and Republic are enough to show Plato's conviction of its philosophical potential.

The slave boy episode is originally introduced by Socrates as a proof of something much more than the possibility of successful inquiry. The suggestion is that the best explanation of that possibility is provided by the doctrine of the immortality of the soul, a Pythagorean belief which makes the first of its many appearances in Plato's dialogues in Meno (see Psych; Pythagoras �2; Pythagoreanism �3). More specifically, the idea as Socrates presents it is that the soul pre-exists the body, in a condition involving conscious possession of knowledge. On entry into the body it forgets what it knows, although it retains it as latent memory. Discovery of the sort of a priori knowledge characteristic of mathematics and (as Plato supposes) ethics is a matter of recollecting latent memory. This is just what happens to the slave boy: Socrates does not impart knowledge to him; he works it out for himself by recovering it from within. Once again, although the Socrates of Meno does not in the end subscribe to belief in learning as recollection of innate knowledge, it is embraced without equivocation in Phaedo, as also in the later Phaedrus. But what exactly is recollected? Phaedo will say: knowledge of Forms. Meno by contrast offers no clues. The introduction of the theory of Forms is reserved for Symposium.

Symposium has the widest appeal of all Plato's writings. No work of ancient Greek prose fiction can match its compulsive readability. Plato moves through a rich variety of registers, from knockabout comedy and literary parody to passages of disturbing fantasy or visionary elevation, culminating in a multiply paradoxical declaration of love for Socrates put in the mouth of a drunken Alcibiades. Love (eros) is the theme of the succession of encomia or eulogies delivered at the drinking party (symposion) hosted by the playwright Agathon: not sublimated 'Platonic' love between the sexes, but the homoerotic passion of a mature man for a younger or indeed a teenager. This continues until Aristophanes (one of the guests) and Socrates broaden and transform the discussion. Socrates' speech, which is a sort of anti-eulogy, develops a general theory of desire and its relation to beauty, and it is in this context that the idea of an eternal and changeless Form makes its first unequivocal appearance in Plato's uvre. Thus Plato first declares himself a metaphysician not in a work devoted to philosophical argument, but in a highly rhetorical piece of writing, albeit one in which fashionable models of rhetoric are subverted.

Love and beauty are first connected in some of the earlier encomia, and notably in Agathon's claim that among the gods 'Love is the happiest of them all, for he is the most beautiful and best' (195a). This thesis is subjected to elenchus by Socrates in the one argumentative section of the dialogue. Agathon is obliged to accept that love and desire are necessarily love and desire for something, namely, something they are in need of. Following his concession Socrates argues that beauty is not what love possesses but precisely the thing it is in need of. This argument constitutes the key move in the philosophy of the dialogue, which Plato elaborates in various ways through the medium of Diotima, the probably fictitious priestess from whom Socrates is made to claim he learned the art of love in which he has earlier (177d) claimed expertise. First she tells a myth representing Love as the offspring of poverty and resource, and so - according to her interpretation - occupying the dissatisfied intermediate position between ignorance and wisdom which characterizes philosophy: hence presumably the explanation of Socrates' claim to be an expert in love, since the pursuit of wisdom turns out to be the truest expression of love. Then she spells out the theoretical basis for this intellectualist construction of what love is. The theory has rightly been said to combine 'a psychology that is strictly or loosely Socratic with a metaphysics that is wholly Platonic' (Price 1995).

This psychology holds that a person who desires something wants not so much the beautiful as the good, or more precisely happiness conceived as permanent possession of the good. Love is a particular species of desire, which occurs when perception of beauty makes us want to reproduce. (Socrates is made to express bafflement at this point: presumably an authorial device for indicating that Diotima's line of thought is now moving beyond anything Plato considered strictly Socratic.) Diotima goes on to explain that reproduction is the way mortal animals pursue immortality, interpreted in its turn in terms of the longing for permanent possession of good with which she has just identified desire. Other animals and many humans are content with physical reproduction, but humans are capable of mental creation when inspired by a beautiful body, and still more by a beautiful soul or personality. This is how the activities of poets and legislators and the virtuous are to be understood.

Perhaps Plato thought these ideas, although no longer Socratic, provided a convincing explanation of the drive which powered Socrates' philosophical activity in general, and made him spend so much time with beautiful young men in particular. However that may be, in what follows he has Diotima speak of greater mysteries which 'I do not know whether you [that is, Socrates] would be able to approach'. These are the subject of a lyrical account of how a true lover moves step by step from preoccupation with the beauty of a single beloved, to appreciating that there is one and the same beauty in all bodies and so loving them all, and then to seeing and loving beauty in souls or personalities and all manner of mental creations, until he 'turns to the great sea of beauty, and gazing upon this gives birth to many gloriously beautiful ideas and theories, in unstinting love of wisdom [that is, philosophy]' (210d). The final moment of illumination arrives when the philosopher-lover grasps the Beautiful itself, an experience described as the fulfilment of all earlier exertions. Unlike other manifestations of beauty the Form of the Beautiful is something eternal, whose beauty is not qualified in place or time or relation or respect. It is just the one sort of thing it is, all on its own, whereas other things that are subject to change and decay are beautiful by participation in the Form. Only someone who has looked upon it will be capable of giving birth not to images of virtue (presumably the ideas and theories mentioned a little earlier), but to virtue itself, and so achieving immortality so far as any human can.

It is striking that the doctrine of the immortality of the soul forms no part of Diotima's argument. If we assume the scholarly consensus that Symposium postdates Meno, this poses something of a puzzle. One solution might be to suppose that, although Meno presents the doctrine, Plato is himself not yet wholly convinced of its truth, and so gives it no role in his account of the desire for immortality in Symposium. This solution might claim support from the fact that Phaedo takes upon itself the task of arguing the case for the immortality of the soul much more strenuously than in Meno, and in particular offers a much more careful and elaborate version of the argument from recollection. Additionally or alternatively, we may note that when Plato presents the doctrine of the immortality of the soul in the dialogues, he always treats it as something requiring explicit proof, unlike the theory of Forms, which generally figures as a hypothesis recommending itself by its explanatory power or its ability to meet the requirements of Plato's epistemology. Since Diotima's discourse is not constructed as argument but as the explication of an idea, it is not the sort of context which would readily accommodate the kind of demonstration Plato apparently thought imperative for discussion of the immortality of the soul.

The departure point for Phaedo's consideration of the fate of the soul after death is very close to that idea of love as desire for wisdom which Diotima offers at the start of her speech in Symposium. For Socrates starts with the pursuit of wisdom, which he claims is really a preparation for death. This is because it consists of an attempt to escape the restrictions of the body so far as is possible, and to purify the soul from preoccupation with the senses and physical desires so that it can think about truth, and in particular about the Forms, which are accessible not to sense perception but only to thought. Pure knowledge of anything would actually require complete freedom from the body. So given that death is the separation of soul from body, the wisdom philosophers desire will be attainable in full only when they are dead. Hence for a philosopher death is no evil to be feared, but something for which the whole of life has been a training. The unbearably powerful death scene at the end of the dialogue presents Socrates as someone whose serenity and cheerfulness at the end bear witness to the truth of this valuation.

Symposium implied that a long process of intellectual and emotional reorientation was required if someone was to achieve a grasp of the Form of Beauty. Phaedo has sometimes been thought to take a different view: interpreters may read its argument about recollecting Forms as concerned with the general activity of concept formation in which we all engage early in life. In fact the passage restricts recollection of Forms to philosophers, and suggests that the knowledge they recover is not the basic ability to deploy concepts (which Plato seems in this period to think a function of sense experience), but hard-won philosophical understanding of what it is to be beautiful or good or just. The interlocutors voice the fear that once Socrates is dead there will be nobody left in possession of that knowledge; and the claim that pure knowledge of Forms is possible only after death coheres with the Symposium account very well, implying as it does that the path to philosophical enlightenment is not just long but a journey which cannot be completed in this life.

The proposal that the soul continues to exist apart from the body after death is immediately challenged by Socrates' interlocutors. Much of the rest of Phaedo is taken up with a sequence of arguments defending that proposal and the further contention that the soul is immortal, pre-existing the body and surviving its demise for ever. The longest and most ambitious of these arguments is the last of the set. It consists in an application of the method of hypothesis, which is explained again in a more elaborate version than that presented in Meno. The hypothesis chosen is the theory of Forms, or rather the idea that Forms function as explanations or causes of phenomena: beautiful things are beautiful by virtue of the Beautiful, large things large by virtue of the Large, and so on. Socrates is made to represent his reliance on this apparently uninformative or 'safe and simple' notion of causation as a position he has arrived at only after earlier intellectual disappointments: first with the inadequacies of Presocratic material causes, then with the failure of Anaxagoras' promise of a teleological explanation of why things are as they are (see Anaxagoras �4).

He soon goes on to argue however that the hypothesis can be used to generate a more sophisticated model of causation. Instead of proposing merely that (for example) hot things are hot by virtue of the Hot, we may legitimately venture the more specific explanation: 'Hot things are hot by virtue of fire', provided that it is true that wherever fire exists, it always heats things in its vicinity, being itself hot and never cold. After elaborating this point Socrates is ready to apply the model to the case of life and soul. By parity of reasoning, we may assert that living things are alive not just in virtue of life, but in virtue of soul, given that wherever soul exists it makes things it occupies alive, being itself alive and never dead. From this assertion there appears to follow the conclusion whose derivation is the object of the exercise: if soul is always alive and never dead, it must be immortal (that is, incapable of death) and so imperishable.

Phaedo, like Republic, ends with a sombre myth of last judgment and reincarnation, designed primarily to drive home the moral implications of Plato's distinctive version of soul-body dualism. It reminds us of the Pythagorean origins of the doctrine of the immortality of the soul. Yet the Platonism of Phaedo owes a great deal also to the metaphysics of Parmenides. Both here and in Symposium the characterization of Forms as simple eternal beings, accessible only to thought, not the senses, and the contrast both dialogues make with the changing and contradictory world of phenomena, are couched in terms borrowed from Parmenides and the Eleatic tradition which he inaugurated. Platonism can accordingly be seen as the product of an attempt to understand a fundamentally Socratic conception of philosophy and the philosophical life in the light of reflection on these two powerful Presocratic traditions of thought, using the new methodological resources made available by geometry.

Republic is misleadingly titled. The Greek name of the dialogue is Politeia, which is the standard word for constitution or ordering of the political structure: 'political order' would give a better sense of what Plato has in mind. There is a further and deeper complication. Once you start reading the dialogue you find that it is primarily an inquiry into justice, conceived as a virtue or moral excellence of individual persons. The philosophical task it undertakes is the project of showing that justice so conceived is in the best interests of the just person, even if it brings nothing ordinarily recognizable as happiness or success, or indeed (as with the sentence of death passed on Socrates) quite the opposite. Thus Republic carries forward the thinking about justice begun in early dialogues such as Apology, Crito and Gorgias. Why, then, the title's suggestion that it is a work of political rather than moral philosophy?

One way of answering this question is to attend to the formal structure of Republic. After book I, an inconclusive Socratic dialogue which none the less introduces, particularly in the conversation with Thrasymachus, many of the themes pursued in the rest of the work, the interlocutors agree to take an indirect approach to the problem of individual justice: they will consider the nature of justice and injustice in the polis, that is the (city-)state, in the hope that it will provide an illuminating analogy. Books II-IV spell out the class structure required in a 'good city'. It is suggested that in such a state political justice consists in the social harmony achieved when each class (economic, military, governing) performs its own and only its own function. This model is then applied to the individual soul (see Psych). Justice and happiness for an individual are secured when each of the parts of the soul (appetite, emotion, reason) performs the role it should in mutual harmony. In working out the idea of psychic harmony, Plato formulates a conception of the complexity of psychological motivation, and of the structure of mental conflict, which leaves the simplicities of Socratic intellectualism far behind, and one which has reminded interpreters of Freudian theory, particularly in books VIII-IX. Here he examines different forms of unjust political order (notably oligarchy, democracy and tyranny) and corresponding conditions of order, or rather increasing disorder, in the soul.

Political theory therefore plays a large part in the argument of the dialogue, even though the ultimate focus is the moral health of the soul, as is confirmed by the conclusion of book IX. Socrates suggests that it may not matter whether we can actually establish a truly just political order, provided we use the idea of it as a paradigm for founding a just city within our own selves.

This account of Republic omits the central books V-VII. These explore the notion of political order much further than is necessary for the purposes of inquiry into individual justice. This is where Plato develops the notion of a communistic governing class, involving the recruitment of talented women as well as men, the abolition of the family, and institution of a centrally controlled eugenic breeding programme. And it is where, in order to meet the problem of how the idea of the just city he has been elaborating might ever be put into practice, he has Socrates introduce philosopher-rulers:

Unless either philosophers rule in our cities or those whom we now call rulers and potentates engage genuinely and adequately in philosophy, and political power and philosophy coincide, there is no end, my dear Glaucon, to troubles for our cities, nor I think for the human race.

(Republic 473c-d)

What Plato perhaps has most in mind when he makes Socrates speak of 'troubles' is as well as civil war the corruption he sees in all existing societies. As he acknowledges, this makes the emergence of an upright philosopher-ruler an improbability - and incidentally leaves highly questionable the prospects of anyone but a Socrates developing moral order within the soul when society without is infected with moral disorder.

Here we touch on another broadly political preoccupation of Republic, worked out at various places in the dialogue. It offers among other things a radical critique of Greek cultural norms. This is highlighted in the censorship of Homer proposed in books II and III, and in the onslaught on the poets, particularly the dramatists, in book X, and in their expulsion from the ideal city. But these are only the more memorable episodes in a systematic attack on Greek beliefs about gods, heroes and the departed, on the ethical assumptions underlying music, dance and gymnastics (see Mimsis), and again erotic courtship, and on medical and judicial practice. Republic substitutes its own austere state educational programme, initially focused on the training of the emotions, but subsequently (in books VI and VII) on mathematics and philosophy. Plato sees no hope for society or the human race without a wholesale reorientation, fostered by an absolute political authority, of all the ideals on which we set our hearts and minds.

Republic itself is written in such a way as to require the reader to be continually broadening perspectives on the huge range of concerns it embraces, from the banalities of its opening conversation between Socrates and the aged Cephalus to its Platonist explication of the very notion of philosophy in the epistemology and metaphysics of books V-VII. At the apex of the whole work Plato sets his presentation of the Form of the Good, as the ultimate goal of the understanding that philosophy pursues by use of the hypothetical method. The dialogue offers a symbol of its own progress in the potent symbol of the cave. We are like prisoners chained underground, who can see only shadows of images flickering on the wall. What we need is release from our mental shackles, and a conversion which will enable us gradually to clamber out into the world above and the sunlight. For then, by a sequence of painful reorientations, we may be able to grasp the Good and understand how it explains all that there is.

Parmenides is that rare phenomenon in philosophy: a self-critique. Plato here makes his own theory of Forms the subject of a penetrating scrutiny which today continues to command admiration for its ingenuity and insight. Theaetetus (datable to soon after 369 bc) also reverts to Plato's critical manner. It applies an enriched variant of the Socratic elenchus to a sequence of attempts to define knowledge. The confidence of Phaedo and Republic that Platonist philosophers are in possession of knowledge and can articulate what it consists in is nowhere in evidence, except in a rhetorical digression from the main argument. Methodological preoccupations are dominant in both works. Parmenides suggests that to defend the Forms against its critique, one would need to be much more practised in argument than is their proponent in this dialogue (a young Socrates fictively encountering a 65-year old Parmenides and a middle-aged Zeno). And it sets out a specimen of the sort of exercise required, running to many pages of purely abstract reasoning modelled partly on the paradoxes of Zeno of Elea, partly on Parmenides' deductions in the Way of Truth (see Parmenides ��3-8). Theaetetus likewise presents itself, initially more or less explicitly, later implicitly, as a model of how to go about testing a theory without sophistry and with due sympathy. While the conclusions achieved by this 'midwifery' - as Socrates here calls it - are as devastatingly negative as in the early dialogues, we learn much more philosophy along the way. Many readers find Theaetetus the most consistently rewarding of all the dialogues.

A sketch of the principal concerns of the two dialogues will bring out their radical character. Parmenides raises two main questions about Forms. First, are there Forms corresponding to every kind of predicate? Not just one and large, or beautiful and just, familiar from the middle period dialogues, but man and fire, or even hair and dirt? Socrates is represented as unclear about the issue. Second, the idea that other things we call for example 'large' or 'just' are related to the Form in question by participation is examined in a succession of arguments which seek to show that, however Forms or the participation relation are construed, logical absurdities of one kind or another result. The most intriguing of these has been known since Aristotle as the Third Man: if large things are large in virtue of something distinct from them, namely the Form of Large, then the Large itself and the other large things will be large in virtue of another Form of Large - and so ad infinitum.

Theaetetus devotes much of its space to considering the proposal that knowledge is nothing but sense perception, or rather to developing and examining two theories with which that proposal is taken to be equivalent: the view of Protagoras (�3) that truth is relative, since 'man is the measure of all things', and that of Heraclitus that everything is in flux, here considered primarily in application to the nature of sense perception. The dialogue is home to some of Plato's most memorable arguments and analogies. For example, Protagoreanism is attacked by the brilliant (although perhaps flawed) self-refutation argument: if man is the measure of all things, then the doctrine of the relativity of truth is itself true only in so far as it is believed to be true; but since people in general believe it to be false, it must be false. The next section of Theaetetus worries about the coherence of the concept of false belief. Here the soul is compared to a wax tablet, with false belief construed as a mismatch between current perceptions and those inscribed on the tablet, or again to an aviary, where false belief is an unsuccessful attempt to catch the right bird (that is, piece of knowledge). In the final section the interlocutors explore the suggestion that knowledge must involve the sort of complexity that can be expressed in a logos or statement. Socrates' 'dream' that such knowledge must be built out of unknowable simples fascinated Wittgenstein (�5), who saw in it an anticipation of the theory of his Tractatus.

Are we to infer that in opening or reopening questions of this kind Plato indicates that he is himself in a real quandary about knowledge and the Forms? Or is his main target philosophical complacency in his readers, as needing to be reminded that no position is worth much if it cannot be defended in strenuous argument? Certainly in the other two dialogues grouped here with Parmenides and Theaetetus the theory of Forms is again in evidence, presented as a view the author is commending to the reader's intellectual sympathies. Cratylus is a work whose closest philosophical connections are with Theaetetus, although its relative date among the dialogues is disputed. It is a pioneering debate between rival theories of what makes a word for a thing the right word for it: convention, or as Cratylus holds, a natural appropriateness - sound somehow mirroring essence (see Language, ancient philosophy of �2). Underlying Cratylus' position is an obscurely motivated commitment to the truth of Heracliteanism (see Cratylus). For present purposes what is of interest is the final page of the dialogue, which takes the theory of Forms as premise for an argument showing that the idea of an absolutely universal Heraclitean flux is unsustainable. As for Phaedrus, it contains one of the most elevated passages of prose about the Forms that Plato ever wrote.

The context is an exemplary rhetorical exercise in which Symposium's treatment of the philosophical lover's attraction to beauty is reworked in the light of Republic's tripartition of the soul. Subsequently Plato has Socrates dismiss the speech as 'play', useful only for the methodological morals about rhetorical procedure we happen to be able to derive from it - together with a preceding denunciation of love by Socrates, capping one by his interlocutor Phaedrus - if we are dialecticians. This comment has led some readers to conjecture that Phaedrus accordingly marks Plato's formal leave-taking of the theory of Forms: in retrospect he sees it more as rhetoric than as philosophy or dialectic, which will henceforward confine itself to something apparently less inspiring - the patient, thorough, comprehensive study of similarities and differences. Yet Phaedrus is pre-eminently a dialogue written not to disclose its author's mind, but to make demands on the sophisticated reader's. Perhaps Socrates' great speech on the philosophical lover is 'play' not absolutely, but only relative to the controlling and unifying preoccupation of the dialogue, which is to work through a fresh examination of rhetoric, going beyond Gorgias in explaining how it can be a genuine form of expertise, based on knowledge of truth and variously geared to the various psychological types to which oratory addresses itself. We might speculate that Plato writes the speech as he does precisely because he thinks or hopes many of his readers will be of a type persuadable to the philosophical life by its vision of the soul's desire for the Beautiful.

The theory of Forms also figures prominently in Timaeus. Timaeus is Plato's one venture into physical theory, and appropriately has in the Italian Greek Timaeus someone other than Socrates as main speaker. It is presented as an introduction to the story of Atlantis, allegedly an island power defeated by the prehistoric Athenians, and mentioned only by Plato among classical Greek authors. The conflict between Atlantis and Athens was to be the subject of Critias, conceived as a dialogue that would demonstrate the political philosophy of Republic in practice. But Critias was never completed, so Timaeus stands as an independent work.

The argument of Timaeus is based on the premise that the universe is not eternal but created - although debate has raged from antiquity onwards whether this means created in time, or timelessly dependent on a first cause. From the order and beauty of the universe Plato infers a good creator or craftsman (dmiourgos), working on pre-existing materials (with their own random but necessary motions) from an eternal blueprint encoding life and intelligence: namely, the Form of Animal. The greater part of Timaeus consists in an account of how first the universe (conceived of as a living creature), then humans are designed from the blueprint for the best. Much use is made of mathematical models, for example for the movements of the heavenly bodies and the atomistic construction of the four elements. The account is presented as inevitably only a 'likely story', incapable of the irrefutable truths of metaphysics.

There is no more austere or profound work of metaphysics in Plato's uvre than Sophist. Like many of the post-Republic dialogues it is 'professional' philosophy, probably written primarily for Plato's students and associates in the Academy. The style of Sophist and the remaining works to be discussed is syntactically tortuous and overloaded with abstraction and periphrasis; they are altogether lacking in literary graces or dramatic properties which might commend them to a wider readership. Sophist's main speaker is a stranger from Elea, symbolizing the Parmenidean provenance of the problem at the heart of the long central section of the dialogue: how is it possible to speak of what is not (see Parmenides �2)? This puzzle is applied for example both to the unreality of images and to falsehood, understood as what is not the case. The solution Plato offers required some revolutionary moves in philosophical logic, such as the explicit differentiation of identity from predication, and the idea that subject and predicate play different roles in the syntax of the sentence. These innovations and their bearing on analysis of the verb 'to be' have made Sophist the subject of some of the most challenging writing on Plato in the twentieth century.

The companion dialogue Politicus or Statesman addresses more squarely than Republic did the practical as distinct from the theoretical knowledge of the ideal statesman. Its contribution to this topic consists of three major claims. First is the rejection of the sovereignty of law. Plato has nothing against law as a convenient but imprecise rule of thumb in the hands of an expert statesman, provided it does not prevent him using his expertise. Making law sovereign, on the other hand, would be like preferring strict adherence to a handbook of navigation or a medical textbook to the judgment of the expert seafarer or doctor. If you have no such expert available, a constitution based on adherence to law is better than lawlessness, but that is not saying much. What law cannot do that expert rulers can and must is judge the kairos: discern the right and the wrong 'moment' to undertake a great enterprise of state. This proposition follows from the second of Plato's key claims, which is represented as one true of all practical arts: real expertise consists not of measuring larger and smaller, but in determining the norm between excess and defect - a notion which we ordinarily think more Aristotelian than Platonic (see Aristotle �22), although it recurs in a different guise in Philebus. Finally, Plato thinks we shall only get our thinking straight on this as on any matter if we find the right - usually homely - model. Statesman makes the statesman a sort of weaver. There are two strands to the analogy. First, like weaving statesmanship calls upon many subordinate skills. Its job is not to be doing things itself, but to control all the subordinate functions of government, and by its concern for the laws and every other aspect of the city weave all together. Second, the opposing temperaments of the citizens are what most need weaving together if civil strife is to be avoided, and (as in Republic) expert rulers will use education and eugenics to that end.

Statesman shares themes with both Philebus and Laws. Philebus is the one late dialogue in which Socrates is principal speaker, as befits its ethical topic: the question whether pleasure or understanding is the good, or at least the more important ingredient in the good life. After so much insistence in middle-period dialogues on the Form as a unity distinct from the plurality of the phenomena, it comes as a shock to find Socrates stressing at the outset that there is no merit in reiterating that pleasure or understanding is a unity. The skill resides in being able to determine what and how many forms of understanding and pleasure there are. What Philebus goes on to offer next is a model for thinking about how any complex structure is produced, whether a piece of music or the universe itself. It requires an intelligent cause creating a mixture by imposing limit and proportion on something indeterminate. This requirement already indicates the main lines of the answer to our problem, at any rate, if it is accepted that pleasure is intrinsically indeterminate. Clearly intelligence and understanding will be shaping forces in the good life, but pleasures are only admissible if suitably controlled. At the adjudication at the end of the dialogue, this is just the result we get. The majority of the many forms of pleasure defined and examined in the course of the dialogue are rejected. They do not satisfy the criteria of measure and proportion which are the marks of the good.

The vast Laws is in its way the most extraordinary of all Plato's later writings, not for its inspiration (which flags) but for its evidence of tireless fascination with things political. Its relation to Republic and Statesman has been much debated. What is clear is that Plato is legislating - through the last eight of its twelve long books - for a second best to the ideal state and ideal statesman of Republic, with greater zeal than Statesman might have led one to expect. Is this because he has lost faith in those ideals, which still seemed alive in Statesman at least as ideals? That view is in danger of overlooking Republic's own indication that it would be wrong to expect in practice anything but an approximation of the ideal.

Philosophers do not often read Laws. But book X presents Plato's natural theology, as the background to laws dealing with atheists. And perhaps the most interesting proposal in the dialogue concerns the very idea of legislation. It is the notion of a 'prelude' to a law, which is the attempt the legislator should make to persuade citizens of the necessity of the prescriptions of the law itself. Here is a theme which relates interestingly to conceptions of reason, necessity and persuasion found in several other dialogues, notably Republic and Timaeus.

Plato's influence pervades much of subsequent Western literature and thought. Aristotle was among those who came to listen to him in the 'school' he founded in the Academy; and a great deal of Aristotle's work is conceived in explicit or implicit response to Plato. Other philosophical traditions flourished after Aristotle's time in the last centuries bc, and the Academy of the period read Plato through sceptical spectacles (see Arcesilaus). But from the first century ad onwards Platonism in various forms, often syncretistic, became the dominant philosophy of the Roman Empire (see Platonism, Early and Middle), especially with the rise of Neoplatonism in late antiquity (see Neoplatonism). Some of the Fathers of the early Greek Church articulated their theologies in Platonist terms; and through Augustine in particular Plato shaped, for example, the Western Church's conception of time and eternity (see Patristic philosophy). A Neoplatonist version of him prevailed among the Arabs (see Platonism in Islamic philosophy).

With the translation of Plato into Latin in the high Middle Ages (see Platonism, medieval) and the revival of Greek studies in the Renaissance, Platonism (again in a Neoplatonic guise) once more gripped the minds of learned thinkers in the West, for example at the Medici court in fifteenth century Florence (see Platonism, Renaissance). But none of the great philosophers of the modern era has been a Platonist, even if Plato was an important presence in the thought of a Leibniz or a Hegel or a Russell. Probably he has never been studied more intensively than in the late twentieth century. Thanks to the availability of cheap translations in every major language and to his position as the first great philosopher in the Western canon, he figures in most introductory courses offered every year to tens of thousands of students throughout the developed world.

List of works

References and further reading

Main Page