Plato and Aristotle were the most influential of all philosophers, ancient, medieval, or modern; and of the two, it was Plato who had the greater effect upon subsequent ages. I say this for two reasons: first, that Aristotle himself is an outcome of Plato; second, that Christian theology and philosophy, at any rate until the thirteenth century, was much more Platonic than Aristotelian. It is necessary therefore, in a history of philosophic thought, to treat Plato, and to a lesser degree Aristotle, more fully than any of their predecessors or successors.
The most important matters in Plato's philosophy are: first, his Utopia, which was the earliest of a long series; second, his theory of ideas, which was a pioneer attempt to deal with the still unsolved problem of universals; third, his arguments in favour of immortality; fourth, his cosmogony; fifth, his conception of knowledge as reminiscence rather than perception. But before dealing with any of these topics, I shall say a few words about the circumstances of his life and the influences which determined his political and philosophical opinions.
Plato was born in 428–7 B.C., in the early years of the Peloponnesian War. He was a well-to-do aristocrat, related to various people who were concerned in the rule of the Thirty Tyrants. He was a young man when Athens was defeated, and he could attribute the defeat to democracy, which his social position and his family connections were likely to make him despise. He was a pupil of Socrates, for whom he had a profound affection and respect; and Socrates was put to death by the democracy. It is not, therefore, surprising that he should turn to Sparta for an adumbration of his ideal commonwealth. Plato possessed the art to dress up illiberal suggestions in such a way that they deceived future ages, which admired the Republic without ever becoming aware of what was involved in its proposals. It has always been correct to praise Plato, but not to understand him. This is the common fate of great men. My object is the opposite. I wish to understand him, but to treat him with as little reverence as if he were a contemporary English or American advocate of totalitarianism.
The purely philosophical influences on Plato were also such as to pre-dispose him in favour of Sparta. These influences, speaking broadly, were: Pythagoras, Parmenides, Heraclitus, and Socrates.
From Pythagoras (whether by way of Socrates or not) Plato derived the Orphic elements in his philosophy: the religious trend, the belief in immortality, the other-worldliness, the priestly tone, and all that is involved in the simile of the cave; also his respect for mathematics, and his intimate intermingling of intellect and mysticism.
From Parmenides he derived the belief that reality is eternal and timeless, and that, on logical grounds, all change must be illusory.
From Heraclitus he derived the negative doctrine that there is nothing permanent in the sensible world. This, combined with the doctrine of Parmenides, led to the conclusion that knowledge is not to be derived from the senses, but is only to be achieved by the intellect. This, in turn, fitted in well with Pythagoreanism.
From Socrates he probably learnt his preoccupation with ethical problems, and his tendency to seek teleological rather than mechanical explanations of the world. 'The Good' dominated his thought more than that of the pre-Socratics, and it is difficult not to attribute this fact to the influence of Socrates.
How is all this connected with authoritarianism in politics?
In the first place: Goodness and Reality being timeless, the best State will be the one which most nearly copies the heavenly model, by having a minimum of change and a maximum of static perfection, and its rulers should be those who best understand the eternal Good.
In the second place: Plato, like all mystics, has, in his beliefs, a core of certainty which is essentially incommunicable except by a way of life. The Pythagoreans had endeavoured to set up a rule of the initiate, and this is, at bottom, what Plato desires. If a man is to be a good statesman, he must know the Good; this he can only do by a combination of intellectual and moral discipline. If those who have not gone through this discipline are allowed a share in the government, they will inevitably corrupt it.
In the third place: much education is needed to make a good ruler on Plato's principles. It seems to us unwise to have insisted on teaching geometry to the younger Dionysius, tyrant of Syracuse, in order to make him a good king, but from Plato's point of view it was essential. He was sufficiently Pythagorean to think that without mathematics no true wisdom is possible. This view implies an oligarchy.
In the fourth place: Plato, in common with most Greek philosophers, took the view that leisure is essential to wisdom, which will therefore not be found among those who have to work for their living, but only among those who have independent means or who are relieved by the State from anxieties as to their subsistence. This point of view is essentially aristocratic.
Two general questions arise in confronting Plato with modern ideas. The first is: is there such a thing as 'wisdom'? The second is: granted that there is such a thing, can any constitution be devised that will give it political power?
'Wisdom', in the sense supposed, would not be any kind of specialized skill, such as is possessed by the shoemaker or the physician or the military tactician. It must be something more generalized than this, since its possession is supposed to make a man capable of governing wisely. I think Plato would have said that it consists in knowledge of the good, and would have supplemented this definition with the Socratic doctrine that no man sins wittingly, from which it follows that whoever knows what is good does what is right. To us, such a view seems remote from reality. We should more naturally say that there are divergent interests, and that the statesman should arrive at the best available compromise. The members of a class or a nation may have a common interest, but it will usually conflict with the interests of other classes or other nations. There are, no doubt, some interests of mankind as a whole, but they do not suffice to determine political action. Perhaps they will do so at some future date, but certainly not so long as there are many sovereign States. And even then the most difficult part of the pursuit of the general interest would consist in arriving at compromises among mutually hostile special interests.
But even if we suppose that there is such a thing as 'wisdom', is there any form of constitution which will give the government to the wise? It is clear that majorities, like general councils, may err, and in fact have erred. Aristocracies are not always wise; kings are often foolish; Popes, in spite of infallibility, have committed grievous errors. Would anybody advocate entrusting the government to university graduates, or even to doctors of divinity? Or to men who, having been born poor, have made great fortunes? It is clear that no legally definable selection of citizens is likely to be wiser, in practice, than the whole body.
It might be suggested that men could be given political wisdom by a suitable training. But the question would arise: what is a suitable training? And this would turn out to be a party question.
The problem of finding a collection of 'wise' men and leaving the government to them is thus an insoluble one. That is the ultimate reason for democracy.