He will.

He will consider whether what he says is true, and whether what he does is
right, in relation to health and disease?

He will.

But can any one attain the knowledge of either unless he have a knowledge
of medicine?

He cannot.

No one at all, it would seem, except the physician can have this knowledge;
and therefore not the wise man; he would have to be a physician as well as
a wise man.

Very true.

Then, assuredly, wisdom or temperance, if only a science of science, and of
the absence of science or knowledge, will not be able to distinguish the
physician who knows from one who does not know but pretends or thinks that
he knows, or any other professor of anything at all; like any other artist,
he will only know his fellow in art or wisdom, and no one else.

That is evident, he said.

But then what profit, Critias, I said, is there any longer in wisdom or
temperance which yet remains, if this is wisdom? If, indeed, as we were
supposing at first, the wise man had been able to distinguish what he knew