The illustration here furnished by Sokrates brings out forcibly the negation of the absolute, and the affirmation of universal relativity in all conceptions, judgments, and predications, which he ascribes to Protagoras and Herakleitus. The predication respecting the six dice denotes nothing real, independent, absolute, inhering in them: for they have undergone no change. It is relative, and expresses a mental comparison made by me or some one else. It is therefore relative in two different senses:--1. To some other object with which the comparison of the dice is made:--2. To me as comparing Subject, who determine the objects with which the comparison shall be made.[31]--Though relativity in both senses is comprehended by the Protagorean affirmation--Homo Mensura--yet relativity in the latter sense is all which that affirmation essentially requires. And this is true of all propositions, comparative or not--whether there be or be not reference to any other object beyond that which is directly denoted. But Plato was here illustrating the larger doctrine which he ascribes to Protagoras in common with Herakleitus: and therefore the more complicated case of relativity might suit his purpose better. [Footnote 31: The Aristotelian Category of Relation ([Greek: ta\ pro\s ti/], Categor. p. 6, a. 36) designates one object apprehended and named relatively to some other object--as distinguished from object apprehended and named not thus relatively, which Aristotle considers as _per se_ [Greek: kath' au(to/] (Ethica Nikomach. i. p. 1096, a. 21). Aristotle omits or excludes relativity of the object apprehended to the percipient or concipient subject, which is the sort of relativity directly noted by the Protagorean doctrine. Occasionally Aristotle passes from relativity in the former sense to relativity in the latter; as when he discusses [Greek: e)pistêto\n] and [Greek: e)pistê/mê], alluded to in one of my former notes on this dialogue. But he seems unconscious of any transition. In the Categories, Object, as implicated with Subject does not seem to have been distinctly present to his reflection. In the third book of the Metaphysica, indeed, he discusses professedly the opinion of Protagoras; and among his objections against it, one is, that it makes everything relative or [Greek: pro\s ti/] (Metaph. [Greek: G]. p. 1011, a. 20, b. 5). This is hardly true in the sense which [Greek: pro\s ti/] bears as one of his Categories: but it is true in the other sense to which I have adverted. A clear and full exposition of what is meant by the Relativity of Human Knowledge, will be found in Mr. John Stuart Mill's most recent work, 'Examination of Sir William Hamilton's Philosophy,' ch. ii. pp. 6-15.] Sokrates now re-states that larger doctrine, in general terms, as follows. [Side-note: Statement of the doctrine of Herakleitus--yet so as to implicate it with that of Protagoras.]