Note 35 — Chapter XI · PHYSICA AND METAPHYSICA.

‘Plato and the Other Companions of Sokrates,’ Vol. II. c. xxvi. pp. 325-363: “The Protagorean doctrine — Man is the measure of all things — is simply the presentation in complete view of a common fact; uncovering an aspect of it which the received phraseology hides. Truth and Falsehood have reference to some believing subject — and the words have no meaning except in that relation. Protagoras brings to view this subjective side of the same complex fact, of which Truth and Falsehood denote the objective side. He refuses to admit the object absolute — the pretended thing in itself — Truth without a believer. His doctrine maintains the indefeasible and necessary involution of the percipient mind in every perception — of the concipient mind in every conception — of the cognizant mind in every cognition. Farther, Protagoras acknowledges many distinct believing or knowing Subjects: and affirms that every object known must be relative to (or in his language, measured by) the knowing Subject: that every cognitum must have its cognoscens, and every cognoscibile its cognitionis capax; that the words have no meaning unless this be supposed; that these two names designate two opposite poles or aspects of the indivisible fact of cognition — actual or potential — not two factors, which are in themselves separate or separable, and which come together to make a compound product. A man cannot in any case get clear of or discard his own mind as a Subject. Self is necessarily omnipresent, concerned in every moment of consciousness, &c.” Compare also c. xxiv. p. 261.