PLATO  , the

great Athenian philosopher, was born in 427 B.C., and lived to the age of eighty . His literary activity may be roughly said to have extended over the first half of the 4th century B.C . His father's name was Ariston, said to have been a descendant of Codrus; and his mother's family, which claimed descent from Solon, included Critias, one of the thirty tyrants, and other well-known Athenians of the early 4th century B.C . That throughout his early manhood he was the devoted friend of Socrates, that in middle life he taught those who resorted to him in the grove named Academus, near the Cephisus, and there founded the first great philosophical school, that (with alleged interruptions) he continued to pre-side over the Academy until his death, are matters of established fact . It is said by Aristotle that he was at one time intimate with Cratylus the Heraclitean . Beyond this we have no authentic record of his outward life . That his name was at first Aristocles, and was changed to Plato because of the breadth of his shoulders or of his style or of his forehead, that he wrestled well,' that he wrote poetry2 which he burnt on hearing Socrates, fought in three great battles,' that he had a thin voice, that (as is told of other Greek philosophers) he travelled to Cyrene and conversed with priests in Egypt, are statements of Diogenes Laertius, which rest on more or less uncertain tradition . The express assertion—which this author attributes to Hermodorus—that after the death of Socrates Plato and other Socratics took refuge with Euclides in Megara, has a somewhat stronger claim to authenticity . But the fact cannot be regarded as certain, still less the elaborate inferences which have been drawn from it . The romantic legend of Plato's journeys to Sicily, and of his relations there with the younger Dionysius and the princely but unfortunate Dion, had obtained some degree See Laws, vii . 814 c . 2 Some epigrams in the Anthology are attributed to him .

3 This is told on the authority of

Aristoxenus . But Plato cannot have been at Deliumof consistency before the age of Cicero, and at an unknown but probably early time was worked up into the so-called Epistles of Plato, now all but universally discredited . Nor is there sufficient ground for supposing, as some have done, that an authentic tradition is perceptible behind the myth . The later years of the Peloponnesian War witnessed much mental disturbance and restlessness at Athens . More than at any time since the age of Cleisthenes, the city was divided, and a man's foes were often men antecedent Conditions . of his own tribe or deme . Contention in the law- courts and rivalries in the assembly had for many men a more absorbing interest than questions of peace and war . Hereditary traditions had relaxed their hold, and political principles were not yet formulated . Yet there was not less scope on this account for personal ambition, while the progress of democracy, the necessity of conciliating the people, and the apportionment of public offices by lot had a distracting and, to reflecting persons, often a discouraging effect . For those amongst Whom Plato was brought up this effect was aggravated by the sequel of the oligarchical revolution, while, on the other hand, for some years after the restoration of the democracy, a new stimulus had been imparted, which, though of short duration, was universally felt . These events appear in two ways to have encouraged the diffusion of ideas . The ambitious seem to have welcomed them as a means of influence, while those who turned from public life were the more stimulated to speculative disputation .

However this may have been, it is

manifest that before the beginning of the 4th century B.C. the intellectual atmosphere was already charged with a new force, which although essentially one may be differently described, according to the mode of its development, as (I) rhetorical and (2) theoretical and " sophistical.” This last word indicates the channel through which the current influences were mostly derived . A new want, in the shape both of inter-. ested and of disinterested curiosity, had insensibly created a new profession . Men of various fatherlands, some native Athenians, but more from other parts of Hellas,' had set themselves to supplement the deficiencies of ordinary education, and to train men for the requirements of civic life . More or less consciously they based their teachings on the philosophical dogmas of an earlier time, when the speculations of Xenophanes, Heraclitus or Parmenides had interested only a few " wise men.” Those great thoughts were now to be expounded, so that " even cobblers might understand.” s The self-appointed teachers found a rich field and abundant harvest among the wealthier youth, to the chagrin of the old-fashioned Athenian, who sighed with Aristophanes for the good old days when men knew less and listened to their elders and obeyed the customs of their fathers . And such distrust was not wholly unfounded . For, amidst much that was graceful and improving, these novel questionings had an influence that, besides being unsettling, was aimless and unreal . A later criticism may discern in them the two great tendencies of naturalism and humanism . But it may be doubted if the sophist was himself aware of the direction of his own thoughts . For, although Prodicus or Hippias could debate a thesis and moralize with effect, they do not appear to have been capable of speculative reasoning . What passed for such was often either verbal quibbling or the pushing to an extreme of some isolated abstract notion . That prudens quaestio which is dimidium scientiae had not yet been put . And yet the hour for putting it concerning human life was fully come .

For the

sea on which men were drifting was profoundly troubled, and would not sink back into its former calm . Conservative reaction was not less hopeless than the dreams of theorists were mischievously wild . In random talk, with gay, irresponsible energy, the youth were debating problems which have exercised great minds in Europe through all after time . Men's thoughts had begun to be thus disturbed and eager when Socrates (q.v.) arose . To understand him is the most necessary preliminary to the study of Plato . There is no reason to doubt ' It had been the policy of Pericles to invite distinguished foreigners to Athens . Theaet . 18o D . Tetrammine salts[Pt(NH3)41X2 Triammine „ [Pt(NH3)3X]X Diammine , [Pt(NH3)2X21 Monammine [Pt(NH3)X3]R the general truth of the assertion, which Plato attributes to him in the Apologia, that he felt a divine vocation to examine Socrates. himself by questioning other men . He was really doing for Athenians, whether they would or no, what the sophist professed to do for his adherents, and what such men as Protagoras and Prodicus had actually done in part . One obvious difference was that he would take no fee . But there was another and more deep-lying difference, which distinguished him not only from the contemporary sophists but from the thinkers of the previous age .

This was the Socratic attitude of inquiry . The sceptical

movement had confused men's notions as to the value of ethical ideas." If " right is one thing in Athens and another in Sparta, why strive to follow right rather than expediency ? The laws put restraint on nature, which is-prior to them . Then why submit to law ? " And the ingenuities of rhetoric had stirred much unmeaning disputation . Every case seemed capable of being argued in opposite ways . Even on the great question of the ultimate constitution of things, the conflicting theories of absolute immutability and eternal change appeared to be equally irrefragable and equally untenable . Men's minds had been confused by contradictory voices--one crying " All is motion," another " All is rest"; one " The absolute is unattainable," another " The relative alone is real " ; some upholding a vague sentiment of traditional right, while some declared for arbitrary convention and some for the law " of nature." Some held that virtue was spontaneous, some that it was due to training, and some paradoxically denied that either vice or falsehood had any meaning . The faith of Socrates, whether instinctive or inspired, remained untroubled by these jarring tones . He did not ask " Is virtue a reality ? " or " Is goodness a delusion ? " But, with perfect confidence that there was an answer, he asked himself and others " What is it?" (ri ivri); or, more particularly, as Xenophon testifies, " What is a state ?

What is a statesman ? What is just ? What is unjust ? What is

government ? What is it to be a ruler of men?" In this form of question, however simple, the originality of Socrates is typified; and by means of it he laid the first stone, not only of the fabric of ethical philosophy, but of scientific method, at least in ethics, logic and psychology . Socrates never doubted that if men once knew what was best, they would also do it . They erred, he thought, from not seeing the good, and not because they would not follow it if seen . This is expressed in the Socratic dicta: " Vice is ignorance," " Virtue is knowledge." This lifelong work of Socrates, in which the germs of ethics, psychology and logic were contained, was idealized, developed, dramatized—first embodied and then extended beyond its original scope—in the writings of Plato, which may be described as the literary outcome of the profound impression made by Socrates upon his greatest follower . These writings (in pursuance of the importance given by Socrates to conversation) are all cast in the form of imaginary dialogue . But in those which are presumably the latest in order of composition this imaginative form interferes but little with the direct expression of the philosopher's own thoughts . The many-coloured veil at first inseparable from the features is gradually worn thinner, and at last becomes almost imperceptible . Plato's philosophy, as embodied in his dialogues, has at once an intellectual and a mystical aspect; and both are dominated Plato's by a pervading ethical motive .

In obeying the Dialogues . Socratic impulse, his speculative

genius absorbed and harmonized the various conceptions which were present in con-temporary thought, bringing them out of their dogmatic isolation into living correlation with one another, and with the life and experience of mankind . His poetical feeling and imagination, taking advantage of Pythagorean and Orphic suggestions, surrounded his abstract reasonings with a halo of mythology which made them more fascinating, but also more difficult for the prosaic intellect to comprehend . Convinced through the conversations of Socrates that truth and good exist and that they are inseparable, persuaded of the unity of virtue and of its dependence upon knowledge, he set forth upon a course of inquiry, " See Caird, Hegel, p . 168.in which he could not rest until the discrepancies of ordinary thinking were not only exposed but accounted for, and resolved in relation to a comprehensive theory . In this " pathway towards reality," from the consideration of particular virtues he passed to the contemplation of virtue in general, and thence to the nature of universals, and to the unity of knowledge and being . Rising still higher on the road of generalization, he discussed the problem of unity and diversity, the one and the many . But in these lofty speculations the facts of human experience were not lost to view . The one, the good, the true, is otherwise regarded by him as the moral ideal, and this is examined as realized both in the individual and in the state . Thus ethical and political speculations are combined . And as the method of inquiry is developed, the leading principles both of logic and of psychology become progressively more distinct and clear . Notwithstanding his high estimate of mathematical principles, to him the type of exactness and certitude, Plato contributed little directly to physical science .

Though he speaks with sympathy and respect of

Hippocrates, he had no vocation for the patient inductive observation of natural processes, through which the Coan physicians, though they obtained few lasting results, yet founded a branch of science that was destined to be beneficently fruitful . And he turned scornfully aside from the Atomists, Leucippus and Democritus, whose first principle, the basis of so much in modern physics, appeared to him to be tainted with materialism . Yet his discursive thought, as in later years he held high intercourse with Archytas and other contemporary minds, could not fail, unlike his master's, to include a theory of the Cosmos in its purview . In this regard, however, the poet-philosopher brought imagination to the aid of reason, thus creating a new mythology, of which the Timaeus is the most conspicuous example . Amidst great diversity, both of subject and of treatment, Plato's dialogues are pervaded by two dominant motives, a passion for human improvement and a persistent faith in the power and supremacy of mind . What is commonly known as his doctrine of Ideas is only one phase in a continuous progress towards the realization of a system of philosophy in which the supreme factor is reason guiding will . But the objectivity, which from the first was characteristic of all Greek thinking, and his own power of poetic presentation, obscured for a time, even for Plato himself, the essential spirituality of his conceptions, and at one time even threatened to arrest them at a stage in which the universal was divorced from the particular, the permanent from the transient, being from becoming, and in which the first principles of reality were isolated from one another as well as from the actual world . Gradually the veil was lifted, and the relation between the senses and the intellect, phenomena and general laws, the active and the contemplative powers, came to be more clearly conceived . The true nature of abstraction and generalization, and of predication and inference, began to be discerned, and speculation was verified through experience . The ideas were seen as categories, or forms of thought, under which the infinite variety of natural processes might be comprised . And thus the dialogues present, as in a series of dissolving views, a sort of model or compendium of the history of philosophy . Plato's system is nowhere distinctly formulated, nor are the views put forward in his dialogues always consistent with each other, but much especially of his later thought is systematized, and as it were crystallized in the treatises of Aristotle; by whom the point of view which Plato had approached, but not finally attained, was made the starting-point for more precise metaphysical determinations and carried into concrete theories having the stamp of a more rigid logical method .

The departments of ethics and politics, of

dialectic and of psychology, of physics and meta-physics, thus came to be more clearly distinguished, but some-thing was lost of the unity and intensity of spiritual insight which had vitalized these various elements, and fused them in a dynamic harmony . The student of philosophy, whatever may be the modern system to which he is most inclined, sensational, intuitional, conceptional, transcendental, will find his account in returning to this well-spring of European thought, in which all previous movements are absorbed, and from which all subsequent lines of reflection may be said to diverge . As was observed by Jowett (St Paul, 1855), " the germs of all ideas, even of most Christian ones, are to be found in Plato." Two great forces are persistent in Plato: the love of truth and zeal for human improvement . -In the period culminating with Historical the Republic, these two motives, the speculative and influence the practical, are combined in one harmonious of Plato. working . In the succeeding period, without excluding one another, they operate with alternate intensity . In the varied outcome of his long literary career, the metaphysical " doctrine of ideas " which has been associated with Plato's name underwent many important changes . But pervading all these there is the same constant belief in the supremacy of reason and the identity of truth and good . From that abiding root spring forth a multitude of thoughts concerning the mind and human things—turning chiefly on the principles of psycho-logy, education and political reform—thoughts which, although unverified, and often needing correction from experience, still constitute Plato the most fruitful of philosophical writers . While general ideas are powerful for good or ill, while abstractions are necessary to science, while mankind are apt to crave after perfection, and ideals, either in art or life, have an acknowledged value, so long the renown of Plato will continue . " All philosophic truth is Plato rightly divined; all philosophic error is Plato misunderstood "—is the verdict of one of the keenest of modern metaphysicians) . Plato's followers, however, have seldom kept the proportions of his teaching . The diverse elements of his doctrine have survived the spirit that informed them .

The pythagorizing

mysticism of the Timaeus has been more prized than the subtle and clear thinking of the Theaetetus . Logical inquiries have been hardened into a barren ontology . Semi-mythical statements have been construed literally and mystic fancies perpetuated without the genuine thought which underlay them . A part (and not the essential part) of his philosophy has been treated as the whole . But the influence of Plato has extended far beyond the limits of the Platonic schools . The debt of Aristotle to his master has never yet been fully estimated . Zeno, Chrysippus, Epicurus borrowed from Plato more than they knew . The moral ideal of Plutarch and that of the Roman Stoics, which have both so deeply affected the modern world, could not have existed without him . Neopythagoreanism was really a crude Neoplatonism . And the Sceptics availed themselves of weapons either forged by Plato or borrowed by him from the Sophists . A wholly distinct line of infiltration is suggested by the mention of Philo and the Alexandrian school (cf. section in Arabian Philosophy, ii . 26bc, 9th edition), and of Clement and Origen, while Gnostic heresies and even Talmudic mysticism betray perversions of the same influence .

The effect of Hellenic thought on Christian

theology and on the life of Christendom is a subject for a volume, and has been pointed out in part by E . Zeller and others (cf . NEo-PLATONISM) . Yet when Plotinus in the 3rd century (after hearing Ammonius), amidst the revival of religious paganism, founded a new spiritualistic philosophy upon the study of Plato and Aristotle combined, this return to the fountain head had all the effect of novelty . And for more than two centuries, from Plotinus to Proclus, the great effort to base life anew on. the Platonic wisdom was continued . But it was rather the ghost than the spirit of Plato that was so " unsphered." Instead of striving to reform the world, the Neoplatonist sought after a retired and cloistered virtue . Instead of vitalizing science with fresh thought, he lost hold of all reality in the contemplation of infinite unity . He had skill in dealing with abstractions, but laid a feeble hold upon the actual world . " Hermes Trismegistus " and "Dionysius Areopagita " are names that mark the continuation of this influence into the middle ages . The pseudo-Dionysius was translated by Erigena in the 9th century . Two more " Platonic" revivals have to be recorded—at `Ferrier, Institutes of Metaphysics, p . 169 (§ i. prop. vi .

§ 12) .

Florence in the 15th and at Cambridge in the 17th century . Both were enthusiastic and both uncritical . The translation of the dialogues into Latin by Marsilio Ficino was the most lasting effect of the former movement, which was tinged with the unscientific ardour of the Renaissance . The preference still accorded to the Timaeus is a fair indication of the tendency to bring fumum ex fulgore which probably marred the discussions of the Florentine Academy concerning the " chief good." The new humanism had also a sentimental cast, which was alien from Plato . Yet the effect of this spirit on art and literature was very great, and may be clearly traced not only in Italian but in English poetry . The " Cambridge Platonists " have been described by Principal Tulloch in his important work on Rational Theology in England in the zgth century, and again by Professor J . A . Stewart in the concluding chapter of his volume on the Myths of Plato . Their views were mainly due to a reaction from the philosophy of Hobbes, and were at first suggested as much by Plotinus as by Plato . It is curious to find that, just as Socrates and Ammonius (the teacher of Plotinus) left no writings, so Whichcote, the founder of this school, worked chiefly through conversation and preaching . His pupils exercised a considerable influence for good, especially on English theology; and in aspiration if not in thought they derived something from Plato, but they seem to have been incapable of separating his meaning from that of his interpreters, and Cudworth, their most consistent writer, was at once more systematic and less scientific than the Athenian philosopher .

The

translations of Sydenham and Taylor in the 18th century and the beginning of the 19th are proofs of the continued influence of Platonism in England . The critical study of Plato begins from Schleiermacher, who did good work as an interpreter, and tried to arrange the dialogues in the order of composition . His attempt, which, critical like many efforts of constructive criticism, went far History. beyond possibility, was vitiated by the ground-fallacy of sup-posing that Plato had from the first a complete system in his mind which he partially and gradually revealed in writing . At a considerably later time Karl Friedrich Hermann, to whom all students of Plato are indebted, renewed the same endeavour on the far more plausible assumption that the dialogues faithfully reflect the growth of Plato's mind . But he also was too sanguine, and exaggerated the possibility of tracing a connexion between the outward events of Plato's life and the progress of his thoughts . This great question of the order of the dialogues, which has been debated by numberless writers, is one which only admits of an approximate solution . Much confusion, however, has been obviated by the hypothesis (first hinted at by Ueberweg, and since supported by Lewis Campbell and others) that the Sophistes and Politicus, whose genuineness had been called in question by Joseph Socher, are really intermediate between the Republic and the Laws . The allocation of these dialogues, not only on grounds of metaphysical criticism, but also on philological and other evidence of a more tangible kind, supplies a point of view from which it becomes possible to trace with confidence the general outlines of Plato's literary and philosophical development . Reflecting at first in various aspects the impressions received from Socrates, he is gradually touched with an inspiration which becomes his own, and which seeks utterance in half-poetical forms . Then first the ethical and by and by the metaphysical interest becomes predominant . And for a while this last is all absorbing, as he confronts the central problems which his own thoughts have raised . But, again, the hard-won acquisitions of this dialectical movement must be fused anew with imagination and applied to life .

And in a final effort to use his intellectual

wealth for the subvention of human need the great spirit passed away . It may not be amiss to recapitulate the steps through which the above position respecting the order of the dialogues has become established . Lovers of Hegel had observed that the point reached in the Sophistes in defining g Dialogues . " not being " was dialectically in advance of the Republic . But Kantian interpreters might obviously have said the same of the Parmenides: and Grote as a consistent utilitarian looked upon the Protagoras as the most mature production of Plato's genius . It seemed desirable to find some criterion that was not bound up with philosophical points of view . Dr Thompson, the Master of Trinity College, Cambridge, had vindicated the genuineness of the Sophistes against the objections of Socher, but had not accounted for the peculiarities of language, which that acute critic had perceived . By comparing those peculiarities with the style of the Laws, Plato's latest work, and with that of the Timaeus and Critics, which presupposed the Republic, Lewis Campbell argued in 1867 that the Sophistes and Politicus, with the Philebus, were in chronological sequence intermediate between the Republic and the Laws . Thus a further defence of their authenticity was at the same time a long step towards the solution of the problem which Schleiermacher had proposed . Many years afterwards the more detailed stylistic investigations of W . Dittenberger, Constantin Ritter and others arrived independently at the same conclusion . It was vehemently supported by W .

Lutoslawski in his work on Plato's Logic, and has been frankly accepted with ample acknowledgments by the high authority of Dr Theodor

Gomperz (see especially the Notes to his Greek Thinkers, 31o, 315 of English translation) .