Plato's Separation of Reason from Desire

Abstract

PLATO'S separation of reason from desire, in Republic 435-9, is made in ten propositions. Plato gives a name to none of these propositions. (Names for propositions, such as 'positivism' or 'Fermat's theorem', had not been invented in his day.) But we may find it convenient to name some of them. Some interpreters have found it convenient to name his first proposition 'The Law of Contradiction'. Others have rejected this name as involving a false description of the proposition laid down in 436 b-437 a. I shall call it here 'The Principle of Opposites'. (1) The Principle of Opposites, 436 b-437 a. This is stated first in 436 b, where I translate: 'It is clear that the same will not do or suffer opposites, at least with regard to the same and towards the same, at the same time.' This differs greatly from our Law of Contradiction in not being explicitly and specifically about propositions. Our Law of Contradiction is a statement about propositions and propositions only. But Plato's Principle of Opposites gives no explicit account whatever of what it is about or what it applies to. Its subject is indicated merely by the phrase 'the same', and therefore appears to be any nameable subject whatever. The only word that could be added to this phrase 'the same', without narrowing the reference, is the word 'entity', since this is the word for referring to any nameable subject whatever, without limitation to any class or category. We might roughly write 'the same thing' in the same sense, because 'thing' is often used in the same all-embracing and colourless reference as 'entity'; but we should be liable to be misunderstood, because 'thing' is often used in another sense, to mean substances as opposed to nonsubstantial entities such as qualities and relations. But does the context indicate that Plato really meant to say something about a narrower class than the class of all entities? Perhaps the verb of his Principle implicitly limits and classifies its subject. This verb is: 'do or suffer.' The subject must therefore be something that logically can do or suffer. Whether that is something less than all entities is hard to say. It certainly does not confine the scope of