Socrates, the Athenian philosopher, was the son of Sophroniscus, a sculptor, and Phænaretē, a midwife. As he was at least seventy years old at his death, he cannot have been born later than 469 B.C. He is said, though only by late writers, to have followed his father's profession for a time; and, in the days of the traveller Pausanias (about 160 A.D.), a statue of the Graces, standing at the entrance to the Acropolis, was ascribed to him—with what amount of truth it is impossible to say. He received the usual education of an Athenian youth, and learned also geometry and astronomy. He was acquainted with the philosophy of Anaxagoras (q.v.), probably only through reading his books, and with other speculations about the physical universe. But he came to consider such inquiries fruitless and disappointing. 'To know one's self' was a more pressing task than to know about nature. The most important influence on his mental development was his intercourse with the various Sophists (q.v.) who frequented Athens. Plato (Meno 96 D) makes him speak as if he had been a pupil of Prodicus; but he was in no sense a disciple of that sophist. Though in Xenophon's Memorabilia (ii. 1) he reproduces Prodicus' moral tale of 'The Choice of Hercules' with approval, he apologises, with obvious irony, for not adorning it with the fine language employed by the sophist, who, we know from Plato's Protagoras, was fond of pedantic verbal distinctions. With the other famous sophists of the time (Protagoras, Gorgias, Hippias, &c.) Socrates stood only in the relation of a controversial disputant, though it is clear from the caricature of him by Aristophanes in the Clouds (423 B.C.) that ordinary Athenian opinion regarded Socrates as a typical sophist. It may be noted also that Aristophanes, following the vulgar conception of a philosopher, represents his sophist Socrates as engaged in physical researches, though many of the sophists, like Socrates himself, occupied themselves not with nature but with questions of direct practical human interest. Socrates, in bringing down philosophy from heaven to the common life of men (as Cicero puts it), was only carrying out in a conspicuous and earnest way one of the new intellectual tendencies of his age. Socrates, we might say, was the greatest of the sophists, and therefore more than a sophist. Euripides, the poet of the new ideas, is said to have been intimate with Socrates; and the comic poets alleged that Socrates helped him with his tragedies. Whether Socrates really met Parmenides (q.v.), as represented by Plato, we have no means of saying.
Socrates took part in three campaigns: he served at Potidæa between 432 and 429, at Delium in 424, and at Amphipolis in 422. His bravery, his extraordinary physical vigour and indifference to fatigue, or cold, or heat, became known to his comrades during these campaigns. He was a good citizen, obedient on principle to the laws of his city; and he did not hesitate to face the anger of the people or of tyrants when duty required. The only political office he ever held was when in 406 he was one of the senate of Five Hundred, and then, whilst he was one of the presiding tribe, he alone refused, at great personal risk, to put to the vote the illegal proposal to try in a body (instead of individually) the generals who had deserted the disabled vessels and left the dead unburied at Arginuse. And, again, during the usurpation of 'The Thirty' he dared to disobey an illegal order. He held aloof from politics, restrained by what he believed to be a divine warning, and considering that he had received a call to the pursuit of philosophy and could serve his country best in that way. Socrates wrote no books. He set up no regular school of philosophy. He simply lived constantly in public, frequenting the gymnasia and the market-place. He did not care to go outside the city walls; 'the trees had nothing to teach him' (as he says in Plato's Phaedrus). It was from men and about men, men of all sorts and conditions, that he desired to learn, wiser than others only in being conscious of his own ignorance. It was in this sense that he interpreted the Delphic oracle, which had said that no one was wiser than Socrates. Out of his wide circle of acquaintances some came to be attached to him more closely by ties of affection and admiration; yet there was no formal bond of discipleship. We should rather speak of the young friends or the companions than of the disciples of Socrates. From two of these, Xenophon and Plato, we learn all we can know with certainty about his strange personality and his way of thinking. Yet there is this difficulty, that, while Plato often makes Socrates the mouthpiece of ideas that were in all probability not held by him, Xenophon, a soldier and by no means a philosopher, makes Socrates a very much more commonplace person than he must have been. And it must be remembered that Xenophon wrote expressly to justify Socrates to the average Athenian. If we were dependent on Xenophon alone, it would be unintelligible how Socrates could have been the initiator of a great movement in philosophy, and how the Athenians could have been suspicious of so safe and conservative a moralist. Though Plato is apparently not bound by any rigid considerations of historical accuracy in his dialogues, we may yet accept the picture he gives us of the habits and conversation of Socrates as a true portrait—a portrait painted by a great imaginative artist. Aristotle, though of course he could only know about Socrates through Plato and others, sometimes supplies us with a valuable test to discriminate the genuinely Socratic from the purely Platonic elements in the dialogues. Xenophon becomes a useful authority when read in the light of what we know from Plato. Many sayings of Socrates convey profounder meanings to the readers of Plato than they probably did to Xenophon himself. Where Xenophon sees only a prudential maxim, Plato finds the germ of a philosophical principle.
In personal appearance Socrates was odd and even ugly, conspicuously so among a handsome race. He had a flat nose, thick lips, prominent eyes. Alcibiades (in Plato's Symposium) compares him to a figure of Silenus. His robust constitution has already been referred to. He always went barefooted, even during a Thracian winter, and wore the same homely clothing all the year round. He was indifferent to luxury and even to ordinary comfort; but he was by no means an ascetic. Habitually abstemious and simple, and possessing perfect control over all his appetites, he could at a banquet drink more than any one else without being overcome. He delighted in the society of youths, especially if they had fair minds in fair bodies. From a modern point of view, he might seem to pay too little regard to the duties of family life. But we must remember that, though above his age in many ways, he was still of it, an Athenian living almost entirely in a society of men. The well-known gossip about his wife Xanthippe comes to us mostly from late sources. Xenophon only tells us that she had a shrewish temper, which Socrates bore patiently, admonishing his eldest son Lamprocles of the duty of gratitude to his mother (Mem. ii. 2). It is easy to believe that a man who had a mission, who was willingly poor, and lived very much in public may have been a trying husband, even to an Athenian wife.
There has been much discussion about the 'divine sign' (daimonion) of which Socrates used to speak as a supernatural voice which guided him every now and then, according to Xenophon telling him to act or not to act, according to Plato only restraining him from action, never instigating. Later writers, especially in Christian times, speak of it as a dæmon, genius, or attendant spirit. For this there is no authority whatever in Plato and Xenophon. On the other hand, we cannot, with some modern writers, identify it with the voice of conscience. Socrates speaks of it as a peculiarity of his own, and it had not to do with the moral quality of actions in general: it was an occasional inward oracle about the future. Socrates, not disbelieving in oracles and divinations (though very likely laying less stress on them than the pious Xenophon would have us suppose), seems to have had certain vivid presentiments which he took for special divine monitions; and it is possible, as has been suggested, that he was subject to occasional hallucinations of hearing, such as may occur even in quite sane and healthy persons. Socrates was eccentric in some ways, and we know that he occasionally became so absorbed in meditation as to become insensible of the outer world. Alcibiades (Plato, Symp. 220) relates that Socrates once stood still for twenty-four hours continuously, entranced in thought. It has also been suggested that in some of his allusions to the divine sign there is a trace of irony, and that he may be indirectly satirising the prevalent belief in divination, claiming to have an oracle of his own.
In any case the average Athenian thought there was something blasphemous in the attitude of Socrates to religion. He was charged in 399, under the restored democracy, (1) with neglecting the gods of the state and introducing new divinities (daimonia), and (2) with corrupting the morals of the young. These were very much the same charges which had been made against him as the typical sophist by Aristophanes twenty-four years before. They were now made the subject of a legal prosecution by Melëtus, Anytus, and Lyco. The Athenian people, though generally tolerant, were liable to outbursts of fanaticism; and it must be remembered that the religion of a Greek state was an integral part of its social and political institutions. Furthermore, among the companions of Socrates had been several of the leading men in the oligarchical faction, such as Critias, Charmides, &c.; and he had also been associated with Alcibiades, who had done so much injury to Athens. A mixture of democratic indignation with that bigoted religious and moral conservatism which is not incompatible with democracy must account for the prosecution and its issues. Plato's Apology probably gives the substance of the actual defence made by Socrates—a bold vindication of his whole life, and not such as would be likely to conciliate an Athenian popular jury. Yet the vote of condemnation was carried only by a very small majority (six out of, probably, 500). The punishment had still to be decided on. Socrates himself declared that, if he were treated as his life deserved, he should be maintained at the public expense in the Prytaneum. But at length, yielding to the pressure of his friends, who were trying to save him, he agreed to pay a fine of thirty minæ (i.e. about £120), for which his friends undertook to be his sureties. Provoked by what doubtless seemed to them obstinacy and insolence in the old man, the judges voted the penalty of 'death,' which Melëtus had proposed in the indictment: according to Diogenes Laertius (q.v.), this was carried by eighty more votes than the original condemnation. The execution of the sentence was delayed for thirty days because of a sacred embassy to Delos. His friends, who had free access to him, planned his escape from prison; but he refused to break the laws of the state. His last day was spent with his friends, as described in Plato's Phædo; and in the evening he drank the hemlock. 'Such was the end,' Plato makes Phædo say, 'of our friend, whom I may truly call the wisest and justest and best of all the men whom I have ever known.' Later writers tell how the Athenians repented and punished his accusers; but there is no evidence for this in the writers of the 4th century B.C.
The life and philosophy of Socrates are inseparably connected. Yet he must not be thought of as simply a good man who tried to influence others for good. He sought to base conduct on knowledge. He went about convincing men not so much of sin as of ignorance. What is called the 'irony' of Socrates is his manner of affecting ignorance in the presence of the seeming wise, in order to draw from them an admission of the confusions and contradictions resulting from their opinions. But his conclusion was not mere scepticism or despair of knowledge. He claimed to follow, in the intellectual sphere, his mother's profession, and to help those in labour with new ideas to bring them to the birth: this is his 'maieutic,' i.e. obstetric art. For this reason he always adopted the method of question and answer—the 'dialectic' method in its literal sense. Aristotle (Met. xiii. 4) says that Socrates introduced the method of induction and the search for general definitions. This is a somewhat technical and formal description of the manner and aim of the conversations of Socrates. The Socratic 'induction' consists in going to particular instances. Socrates was laughed at for the homeliness of his illustrations: he was always talking about carpenters and weavers and shoe-makers.
Ethics was the only part of philosophy with which Socrates cared to occupy himself, and in ethics his main doctrine may be summed up in the formula 'Virtue is knowledge; vice is ignorance.' (Bentham's saying, 'Vice is miscalculation,' is a somewhat mean-looking version of this.) It follows from this fundamental principle that virtue is one, the excellence of each good quality just consisting in the knowing what ought or ought not to be done. It follows also that no one can know (in the truest sense) what is right and yet do what is wrong. In Xenophon we do not find Socrates maintaining any of these opinions in quite so explicit and paradoxical a form. In Plato they are carried out to their logical consequences (see PLATO). We find, e.g., that Xenophon makes Socrates say that rulers should be those who know the art of ruling. This sounds commonplace enough. But we cannot say that Socrates did not go on to propound Plato's paradox that the perfect state would therefore be one in which the rulers were philosophers.
Xenophon represents Socrates as using the argument from design to prove the existence of the gods. But we cannot say with certainty how far his opinions about the gods differed from those of the popular religion. We may fairly suppose that they approached more nearly to those of Plato than to those of the average Athenian. On the other hand, from the language of Plato's Apology, it seems pretty clear that Socrates did not hold the definite views about the immortality of the soul which are maintained in the Phædo, but left the question of a future life quite uncertain.
Socrates founded no special school of philosophy, but gave their starting-point to several distinct schools. Euclides of Megara (not to be confounded with the great mathematician of Alexandria who lived a century later) took up the Socratic dialectic as his main object of study, and, combining Socratic with Eleatic influences, became the founder of the Megaric or 'Eristic' (i.e. disputatious) school. On the other hand, Antisthenes (q.v.) the 'Cynic,' who taught that virtue was the sole end of life, and Aristippus (q.v.) of Cyrene, who taught that pleasure was the end, neglected the intellectual and logical aspects of the Socratic teaching and took a narrowly practical view of the object of philosophy, each maintaining an opposite extreme in his view of goodness. These are often called the 'one-sided' or imperfect Socratics. Plato alone inherited his master's spirit in its fullness.
The part of Zeller's History of Greek Philosophy dealing with Socrates is published separately in the English translation. The materials for the life and teaching of Socrates are Xenophon's Memorabilia and Symposium (the Apology ascribed to Xenophon is probably spurious), and Plato, Apology (most strictly historical of his writings), Crito, the narrative parts of the Phædo, Symposium. For further references, see XENOPHON, PLATO; see also article on 'the demon of Socrates,' by H. Jackson, in Journal of Philology, vol. v.