The wine which I drink when I am well is pleasant to me, but the same wine
is unpleasant to me when I am ill. And there is nothing else from which I
can receive the same impression, nor can another receive the same
impression from the wine. Neither can I and the object of sense become
separately what we become together. For the one in becoming is relative to
the other, but they have no other relation; and the combination of them is
absolute at each moment. (In modern language, the act of sensation is
really indivisible, though capable of a mental analysis into subject and
object.) My sensation alone is true, and true to me only. And therefore,
as Protagoras says, "To myself I am the judge of what is and what is not."
Thus the flux of Homer and Heracleitus, the great Protagorean saying that
"Man is the measure of all things," the doctrine of Theaetetus that
"Knowledge is perception," have all the same meaning. And this is thy new-
born child, which by my art I have brought to light; and you must not be
angry if instead of rearing your infant we expose him.'

'Theaetetus will not be angry,' says Theodorus; 'he is very good-natured.
But I should like to know, Socrates, whether you mean to say that all this
is untrue?'

'First reminding you that I am not the bag which contains the arguments,
but that I extract them from Theaetetus, shall I tell you what amazes me in
your friend Protagoras?'

'What may that be?'

'I like his doctrine that what appears is; but I wonder that he did not
begin his great work on Truth with a declaration that a pig, or a dog-faced
baboon, or any other monster which has sensation, is a measure of all
things; then, while we were reverencing him as a god, he might have