Aristotle on Truth

Thought is the primary realm in which truth and falsity may occur and speech the secondary realm of this occurrence while the realm of external being has no truth and falsity in itself. The first and last points are directly asserted by Aristotle in one text: ‘Falsity and truth are not in things-it is not as if the good were true, and the bad were in itself false- but in thought.’ (Met., E, 1027b25-27; cf. Met., K, 1065a22-23) The second point is also somehow implied: ‘As there are in the mind thoughts which do not involve truth and falsity, and those which must be either true or false, so it is in speech.’ (OI, I, 1, 16a9-11) 1) Truth and falsity belong only to co-positings and positing aways and not to incomposites Truth and falsity do not belong to the realm of external being but only to the realms of thought and language. However, they do not belong to all the elements in these realms. Neither do they belong to incomposite elements in thought (‘With regard to simple things and essences, falsity and truth do not exist even in thought.’ (Met., E, 1027b26-28; So., Γ, 6, 430a26-b4)), nor to such elements in language. Consequently, all incomposites are incapable of being true or false. (cf. Met., Θ, 1051b17-22 and b26-27) Where we have no co-positing or positing away, of the kind made by copula or verb, we cannot have truth and falsity though we can have significance: ‘“Man” and “white”, as isolated terms, are not yet either true or false. In proof of this, consider the word “good-stag.” It has significance, but there is no truth or falsity about it, unless “is” or “is not” is added, either in present or in some other tense.’ (OI., I, 1, 16a14-18) Therefore, any other kind of co-positing cannot be the subject of truth and falsity. One good example of co-positings not made by copula or verbs are simple negations: ‘He that uses the expression ‘not-man,’ if nothing more be added, is not nearer but farther from making a true or a false statement than he who uses the expression “man.”’ (OI., I, 10, 20a34-36) It is indeed a co-positing or a positing away that is the subject of truth and falsity: ‘For it is co-positing (σύνθεσιν) and positing away (διαίρεσιν) that truth and falsity is about.’ (OI., I, 1, 16a12-13) Co-positing is so vital for truth-falsity that ‘of the things that are never said based on co-positing, nothing is true or false.’ (Cat., 10, 13b9-11) This co-positing can be both in thought (‘where the alternative of true or false applies, there we always find a sort of combining of objects of thought in a quasi-unity … For falsehood always involves a combining’ (So., Γ, 6, 430a26-b2) and ‘truth or false is a co-positing of concepts of thought’ (So., Γ, 6, 430a11-12) and in language because they are produced in thought: ‘There is not only the true or false assertion that Cleon is white but also the true or false assertion that he was or will be white. In each and every case that which unifies is thought.’ (So., Γ, 6, 430b4-6) 2) Correspondence to external world Although truth and falsity belong to thought and language and not to external world, their basis is in the external world. It is, in fact, the correspondence of thought and language to external world that makes what is true, true and what is false, false: ‘To say of what is that it is, or of what is not that it is not, is false, while to say of what is that it is, and of what is not that is not, is true.’ (Met., Γ, 1011b26-27; cf. Met., Θ, 1051b2-5) When the two realms are correspondent, we can transfer from one to the other: ‘If it is true to say that a thing is white, it must necessarily be white; if the reverse proposition be true, it will of necessity not be white. Again, if it is white, the proposition stating that it is white was true; if it is not white, the proposition to the opposite effect was true. And if it is not white, the man who states that it is making a false statement, it follows that it is not w