time hiding from me the fact that the life according to knowledge is not
that which makes men act rightly and be happy, not even if knowledge
include all the sciences, but one science only, that of good and evil.
For, let me ask you, Critias, whether, if you take away this, medicine will
not equally give health, and shoemaking equally produce shoes, and the art
of the weaver clothes?--whether the art of the pilot will not equally save
our lives at sea, and the art of the general in war?

Quite so.

And yet, my dear Critias, none of these things will be well or beneficially
done, if the science of the good be wanting.

True.

But that science is not wisdom or temperance, but a science of human
advantage; not a science of other sciences, or of ignorance, but of good
and evil: and if this be of use, then wisdom or temperance will not be of
use.

And why, he replied, will not wisdom be of use? For, however much we
assume that wisdom is a science of sciences, and has a sway over other
sciences, surely she will have this particular science of the good under
her control, and in this way will benefit us.

And will wisdom give health? I said; is not this rather the effect of
medicine? Or does wisdom do the work of any of the other arts,--do they
not each of them do their own work? Have we not long ago asseverated that
wisdom is only the knowledge of knowledge and of ignorance, and of nothing
else?