Man is the measure of all things
From The Art and Popular Culture Encyclopedia
Like many fragments of the Presocratics, this phrase has been passed down to us without any context, and its meaning is open to interpretation. However, the use of the word χρήματα (chrēmata) instead of the general word ὄντα (onta, entities) signifies that Protagoras was referring to things that are used by or in some way related to humans. This makes a great difference in the meaning of his aphorism. Properties, social entities, ideas, feelings, judgements, etc. are certainly χρήματα and hence originate in the human mind. However, Protagoras has never suggested that man must be the measure of the motion of the stars, the growing of plants or the activity of volcanoes.
"πάντων χρημάτων μέτρον ἐστὶν ἄνθρωπος, τῶν μὲν ὄντων ὡς ἔστιν, τῶν δὲ οὐκ ὄντων ὡς οὐκ ἔστιν"
Criticism by Russell
- "For this reason greatness of soul is not fostered by those philosophies which assimilate the universe to Man. Knowledge is a form of union of Self and not-Self; like all union, it is impaired by dominion, and therefore by any attempt to force the universe into conformity with what we find in ourselves. There is a widespread philosophical tendency towards the view which tells us that Man is the measure of all things, that truth is man-made, that space and time and the world of universals are properties of the mind, and that, if there be anything not created by the mind, it is unknowable and of no account for us. This view, if our previous discussions were correct, is untrue; but in addition to being untrue, it has the effect of robbing philosophic contemplation of all that gives it value, since it fetters contemplation to Self. What it calls knowledge is not a union with the not-Self, but a set of prejudices, habits, and desires, making an impenetrable veil between us and the world beyond. The man who finds pleasure in such a theory of knowledge is like the man who never leaves the domestic circle for fear his word might not be law."--The Problems of Philosophy (1912) by Bertrand Russell