ests of seeing and hearing--has art in itself, I say, any
similar liability to fault or defect, and does every art require another
supplementary art to provide for its interests, and that another and
another without end? Or have the arts to look only after their
own interests? Or have they no need either of themselves or of
another?--having no faults or defects, they have no need to correct
them, either by the exercise of their own art or of any other; they have
only to consider the interest of their subject-matter. For every art
remains pure and faultless while remaining true--that is to say, while
perfect and unimpaired. Take the words in your precise sense, and tell
me whether I am not right.

Yes, clearly.

Then medicine does not consider the interest of medicine, but the
interest of the body?

True, he said.

Nor does the art of horsemanship consider the interests of the art of
horsemanship, but the interests of the horse; neither do any other arts
care for themselves, for they have no needs; they care only for that
which is the subject of their art?

True, he said.

But surely, Thrasymachus, the arts are the superiors and rulers of their
own subjects?

To this he assented with a good deal of reluctance.

Then, I said, no science or art considers or enjoins the interest of the
stronger or superior, but only the interest of the subject and weaker?

He made an attempt to contest this proposition also, but finally
acquiesced.

Then, I continued, no physician, in so far as he is a physician,
considers his own good in what he prescribes, but the good of his
patient; for the true physician is also a ruler having the human body as
a subject, and is not a mere money-maker; that has been admitted?

Yes.

And the pilot likewise, in the strict sense of the term, is a ruler of
sailors and not a mere sailor?

That has been admitted.

And such a pilot and ruler will provide and prescribe for the interest
of the sailor who is under him, and not for his own or the ruler's
interest?

He gave a reluctant 'Yes.'

Then, I said, Thrasymachus, there is no one in any rule who, in so far
as he is a ruler, considers or enjoins what is for his own interest, but
always what is for the interest of his subject or suitable to his art;
to that he looks, and that alone he considers in everything which he
says and does.

When we had got to this point in the argument, and every one saw that
the definition of justice had bee