This search after a scientific basis for conduct was quite in the spirit of Socrates, but Plato seems to have set very little value on his master’s positive contributions to the systematisation of life. We have seen that the Apologia is purely sceptical in its tendency; and we find a whole group of Dialogues, probably the earliest of Plato’s compositions, marked by the same negative, inconclusive tone. These are commonly spoken of as Socratic, and so no doubt they are in reference to the subjects discussed; but they would be more accurately described as an attempt to turn the Socratic method against its first originator. We know from another source that temperance, fortitude, and piety were the chief virtues inculcated and practised by Socrates; while friendship, if not strictly speaking a virtue, was equally with them one of his prime interests in life. It is clear that he considered them the most appropriate and remunerative subjects of philosophical discussion; that he could define their nature to his own satisfaction; and that he had, in fact, defined them as so many varieties of wisdom. Now, Plato has devoted a separate Dialogue to each of the conceptions in question,119 and in each instance he represents Socrates, who is the principal spokesman, as professedly ignorant of the whole subject under discussion, offering no definition of his own (or at least none that he will stand by), but asking his interlocutors for theirs, and pulling it to pieces when it is given. We do, indeed, find a tendency to resolve the virtues into knowledge, and, so far, either to identify them with one another, or to carry them up into the unity of a higher idea. To this extent Plato follows in the footsteps of his master, but a result which had completely satisfied Socrates became the starting-point of a new investigation with his successor. If virtue is knowledge, it must be knowledge of what we most desire—of the good. Thus the original difficulty returns under another form, or rather we have merely restated it in different terms. For, to ask what is temperance or fortitude, is equivalent to asking what is its use. And this was so obvious to Socrates, that, apparently, he never thought of distinguishing between the two questions. But no sooner were they distinguished than his reduction of all morality to a single principle was shown to be illusive. For each specific virtue had been substituted the knowledge of a specific utility, and that was all. Unless the highest good were one, the means by which it was sought could not converge to a single point; nor, according to the new ideas, could their mastery come under the jurisdiction of a single art.
We may also suspect that Plato was dissatisfied not only with the positive results obtained by Socrates, but also with the Socratic method of constructing general definitions. To rise from the part to the whole, from particular instances to general notions, was a popular rather than a scientific process; and sometimes it only amounted to taking the current explanations and modifying them to suit the exigencies of ordinary experience. The resulting definitions could never be more than tentative, and a skilful dialectician could always upset them by producing an unlooked-for exception, or by discovering an ambiguity in the terms by which they were conveyed.
Before ascertaining in what direction Plato sought for an outlet from these accumulated difficulties, we have to glance at a Dialogue belonging apparently to his earliest compositions, but in one respect occupying a position apart from the rest. The Crito tells us for what reasons Socrates refused to escape from the fate which awaited him in prison, as, with the assistance of generous friends, he might easily have done. The aged philosopher considered that by adopting such a course he would be setting the Athenian laws at defiance, and doing what in him lay to destroy their validity. Now, we know that the historical Socrates held justice to consist in obedience to the law of the land; and here for once we find Plato agreeing with him on a definite and positive issue. Such a sudden and singular abandonment of the sceptical attitude merits our attention. It might, indeed, be said that Plato’s inconsistencies defy all attempts at reconciliation, and that in this instance the desire to set his maligned friend in a favourable light triumphed over the claims of an impracticable logic. We think, however, that a deeper and truer solution can be found. If the Crito inculcates obedience to the laws as a binding obligation, it is not for the reasons which, according to Xenophon, were adduced by the real Socrates in his dispute with the Sophist Hippias; general utility and private interest were the sole grounds appealed to then. Plato, on the other hand, ignores all such external considerations. True to his usual method, he reduces the legal conscience to a purely dialectical process. Just as in an argument the disputants are, or ought to be, bound by their own admissions, so also the citizen is bound by a tacit compact to fulfil the laws whose protection he has enjoyed and of whose claims his protracted residence is an acknowledgment. Here there is no need of a transcendent foundation for morality, as none but logical considerations come into play. And it also deserves to be noticed that, where this very idea of an obligation based on acceptance of services had been employed by Socrates, it was discarded by Plato. In the Euthyphro, a Dialogue devoted to the discussion of piety, the theory that religion rests on an exchange of good offices between gods and men is mentioned only to be scornfully rejected. Equally remarkable, and equally in advance of the Socratic standpoint, is a principle enunciated in the Crito, that retaliation is wrong, and that evil should never be returned for evil.120 And both are distinct anticipations of the earliest Christian teaching, though both are implicitly contradicted by the so-called religious services celebrated in Christian churches and by the doctrine of a divine retribution which is only not retaliatory because it is infinitely in excess of the provocation received.
If the earliest of Plato’s enquiries, while they deal with the same subjects and are conducted on the same method as those cultivated by Socrates, evince a breadth of view surpassing anything recorded of him by Xenophon, they also exhibit traces of an influence disconnected with and inferior in value to his. On more than one occasion121 Plato reasons, or rather quibbles, in a style which he has elsewhere held up to ridicule as characteristic of the Sophists, with such success that the name of sophistry has clung to it ever since. Indeed, some of the verbal fallacies employed are so transparent that we can hardly suppose them to be unintentional, and we are forced to conclude that the young despiser of human wisdom was resolved to maintain his thesis with any weapons, good or bad, which came to hand. And it seems much more likely that he learned the eristic art from Protagoras or from his disciples than from Socrates. Plato spent a large part of his life in opposing the Sophists—that is to say, the paid professors of wisdom and virtue; but in spite of, or rather perhaps because of, this very opposition, he was profoundly affected by their teaching and example. It is quite conceivable, although we do not find it stated as a fact, that he resorted to them for instruction when a young man, and before coming under the influence of Socrates, an event which did not take place until he was twenty years old; or he may have been directed to them by Socrates himself. With all its originality, his style bears traces of a rhetorical training in the more elaborate passages, and the Sophists were the only teachers of rhetoric then to be found. His habit of clothing philosophical lessons in the form of a myth seems also to have been borrowed from them. It would, therefore, not be surprising that he should cultivate their argumentative legerdemain side by side with the more strict and severe discipline of Socratic dialectics.
Plato does, no doubt, make it a charge against the Sophists that their doctrines are not only false and immoral, but that they are put together without any regard for logical coherence. It would seem, however, that this