The general gist of the argument is as follows. Pleasure could not be regarded as a sufficient or perfect good if it was entirely emptied of the purely intellectual elements of anticipation and consciousness and memory. This would be no better than the pleasure of an oyster. On the other hand, a purely intellectual existence can hardly be regarded as perfect and sufficient either. The perfect life must be a union of both.
But this union must be an orderly and rational union; in other words, it must be one in which Mind is master and Pleasure servant; the finite, the regular, the universal must govern the indefinite, variable, particular. Thus in the perfect life there are four elements; in the body, earth, water, air, fire; in the soul, the finite, the indefinite, the union of the {157} two, and the cause of that union. If this be so, he argues, may we not by analogy argue for a like four-fold order in the universe? There also we find regulative elements, and indefinite elements, and the union of the two. Must there not also be the Great Cause, even Divine Wisdom, ordering and governing all things?
The second of the psychological series is the Parmenides, in which the great Eleatic philosopher, in company with his disciple Zeno, is imagined instructing the youthful Socrates when the two were on a visit to Athens, which may or may not be historical (see above, p. 34). The most striking portion of this dialogue is the criticism already alluded to of Plato's own theory of Ideas, put into the mouth of Parmenides. Parmenides ascertains from Socrates that he is quite clear about there being Ideas of Justice, Beauty, Goodness, eternally existing, but how about Ideas of such common things as hair, mud, filth, etc.? Socrates is not so sure; to which Parmenides rejoins that as he grows older philosophy will take a surer hold of him, and that he will recognise the same law in small things and in great.
But now as to the nature of these Ideas. What, Parmenides asks, is the relation of these, as eternally existing in the mind of God, to the same ideas as possessed by individual men? Does each individual actually partake in the thought of God through {158} the ideas, or are his ideas only resemblances of the eternal? If he partakes, then the eternal ideas are not one but many, as many as the persons who possess them. If his ideas only resemble, then there must be some basis of reference by which the resemblance is established, a tertium quid or third existence resembling both, and so ad infinitum. Socrates is puzzled by this, and suggests that perhaps the Ideas are only notions in our minds. But to this it is replied that there is an end in that case of any reality in our ideas. Unless in some way they have a true and causal relation with something beyond our minds, there is an end of mind altogether, and with mind gone everything goes.
This, as Professor Jowett remarks, "remains a difficulty for us as well as for the Greeks of the fourth century before Christ, and is the stumbling-block of Kant's Critic, and of the Hamiltonian adaptation of Kant as well as of the Platonic ideas. It has been said that 'you cannot criticise Revelation.' 'Then how do you know what is Revelation, or that there is one at all?' is the immediate rejoinder. 'You know nothing of things in themselves.'—'Then how do you know that there are things in themselves?' In some respects the difficulty pressed harder upon the Greek than upon ourselves. For conceiving of God more under the attribute of knowledge than we do, he was more under the necessity of {159} separating the divine from the human, as two spheres which had no communication with one another."
Next follows an extraordinary analysis of the ideas of 'Being' and 'Unity,' remarkable not only for its subtlety, but for the relation which it historically bears to the modern philosophic system of Hegel. "Every affirmation is ipso facto a negation;" "the negation of a negation is an affirmation;" these are the psychological (if not metaphysical) facts, on which the analysis of Parmenides and the philosophy of Hegel are both founded.
We may pass more rapidly by the succeeding dialogues of the series: the Theaetetus (already quoted from above, p. 89), which is a close and powerful investigation of the nature of knowledge on familiar Platonic lines; the Sophist, which is an analysis of fallacious reasoning; and the Statesman, which, under the guise of a dialectical search for the true ruler of men, represents once more Plato's ideal of government, and contrasts this with the ignorance and charlatanism of actual politics.
In relation to subsequent psychology, and more particularly to the logical system of Aristotle, these dialogues are extremely important. We may indeed say that the systematic logic of Aristotle, as contained in the Organon, is little more than an abstract {160} or digest of the logical theses of these dialogues. Definition and division, the nature and principle of classification, the theory of predication, the processes of induction and deduction, the classification and criticism of fallacies,—all these are to be found in them. The only addition really made by Aristotle was the systematic theory of the syllogism.
The Laws, the longest of Plato's works, seems to have been composed by him in the latest years of his long life, and was probably not published till after his death. It bears traces of its later origin in the less artful juncture of its parts, in the absence of humour, in the greater overloading of details, in the less graphic and appropriate characterisation of the speakers. These speakers are three—an Athenian, a Cretan, and a Spartan. A new colony is to be led forth from Crete, and the Cretan takes advice of the others as to the ordering of the new commonwealth. We are no longer, as in The Republic, in an ideal world, a city coming down from, or set in, the heavens. There is no longer a perfect community; nor are philosophers to be its kings. Laws more or less similar to those of Sparta fill about half the book. But the old spirit of obedience and self-sacrifice and community is not forgotten; and on all men and women, noble and humble alike, the duty is cast, to bear in common the common burden of life.
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