Plato

Hence it is improbable that the analysis originated with Plato himself. More probably it was, as the Stoic Poseidonius asserted, a piece of earlier Pythagorean doctrine, as is also suggested by the constant recurrence, throughout the section of the Republic in which the analysis is offered, of analogies from the specially Pythagorean science of Harmonics, and by the fact that the same doctrine is taught by the Pythagorean speaker in the Timaeus. Plato has, however, worked the theory into his ethics so com pletely that through him it has actually become a part of the psychology of Thomism, where it has to be squared, not quite satisfactorily, with the radically divergent psychological scheme of Aristotle.

In point of fact, the tripartite

schema proves inadequate in the Republic itself when we advance in Bk. VI. to the consideration of the moral life of the "philosopher-king," whose "virtue" is founded on a personal knowledge of good. A higher level of moral good ness is demanded of him than of other citizens even of the ideal Utopia; his courage, for example, is declared to be no mere loyalty to right opinions inculcated by early education, but a high serenity arising from the knowledge of the relative insignificance of a brief individual life in the great universe which lies open to his con templation. This has an important bearing on the teaching of the Republic about the unity of virtue.

In the ideal State itself, virtue does not appear as a complete unity. The leading types of moral excellence receive their several definitions. It is recognized that a special demand may be made on a particular section of the society in respect of a particular virtue of which it is, so to say, the public organ, as the fighting force is of the valour of the whole society. This is because, even in the ideal state, the moral convictions of citizens, other than the men of superlative intelligence and character who become "kings," are not supposed to arise from personal insight. They rest on opinions implanted by education, and are thus taken on trust. The good civilian or soldier, after all, is not living by a knowledge which is his own. But the rulers, by whose knowledge the rest of the community lives, must not, of course, themselves take their con victions on trust. They must know with a personal knowledge. The foundation of their virtue must be insight into a system of absolute values embodied in the very structure of the universe. In virtue of this deeper foundation the virtues in them are, so to say, transubstantiated and can no longer be distinguished from one another. They will fuse in knowledge of the good, as, in the Christian saints, they are fused in knowledge and love of God.

It is in this form that the Socratic doctrine, "all virtue is one thing, knowledge" reappears in the Republic as the foundation of a society in which mankind has at last "escaped from its wretch edness," because knowledge rules.

In the

Republic, as in the Phaedo, the Forms (i&at., €1377) ap is expressly made to teach that the Ovtioetak and bnOvininK6 are a "mortal element" (Ovnr6v eThos) added to the immortal soul to fit it for its habitation in the body (Tim. 69c.).

pear in the double character of objects of all genuine science and formal causes of the world of events and processes. It is expressly denied that there can be knowledge, in the proper sense of the word, of the temporal and mutable. In the scheme laid down for the intellectual training of the philosophic rulers, ten years, from the age of zo to that of 3o, are assigned for systematic study of the exact sciences in the order : arithmetic, plane geometry, solid geometry, astronomy and harmonics. Special stress is laid on the points that the object of these studies is not practical applications but the familiarizing of the mind with relations between terms which can only be apprehended by thought, and that diagrams and models are to be treated merely as incidental aids to imagina tion. Five years are then further to be given to the still severer study which Plato calls "dialectic," a study which avails itself of no sensible aids to imagination. It proceeds "by means of Forms, through Forms, to Forms" (51 b.). It is, in fact, what we should call a critical metaphysic of the sciences. It examines the broNo-as or unproved postulates, of the various sciences, and its object is to "destroy" their character as unproved ultimate postulates (ras broNa-Ets Itvatpolua 533 c) by discovering some still more ultimate really self-evident principle (an avi7t-606-rov, 511 b) from which they follow as consequences.

There can be no doubt that this most ultimate principle which is more than a "postulate" means the Good or Form of Good (ibis ra•yaOov) which is said to be the source at once of the reality and the knowability of all that is real and knowable, though it is itself neither knowledge nor being, but transcendent of both (509 b.). On the methodological side the Republic thus completes the teaching of the Phaedo by providing the answer to the question then left open, when a "postulate" may be regarded as finally established. It may be so regarded when it is seen to fol low itself from the Good, which is the principle at once of existence and of value.