is already ensured
whenever all the requirements of it are satisfied. And that was what I
was saying just now about the ruler. I conceived that the art of the
ruler, considered as ruler, whether in a state or in private life,
could only regard the good of his flock or subjects; whereas you seem
to think that the rulers in states, that is to say, the true rulers,
like being in authority.

Think! Nay, I am sure of it.

Then why in the case of lesser offices do men never take them willingly
without payment, unless under the idea that they govern for the
advantage not of themselves but of others? Let me ask you a question:
Are not the several arts different, by reason of their each having a
separate function? And, my dear illustrious friend, do say what you
think, that we may make a little progress.

Yes, that is the difference, he replied.

And each art gives us a particular good and not merely a general
one--medicine, for example, gives us health; navigation, safety at sea,
and so on?

Yes, he said.

And the art of payment has the special function of giving pay: but we
do not confuse this with other arts, any more than the art of the pilot
is to be confused with the art of medicine, because the health of the
pilot may be improved by a sea voyage. You would not be inclined to
say, would you, that navigation is the art of medicine, at least if we
are to adopt your exact use of language?

Certainly not.

Or because a man is in good health when he receives pay you would not
say that the art of payment is medicine?

I should say not.

Nor would you say that medicine is the art of receiving pay because a
man takes fees when he is engaged in healing?

Certainly not.

And we have admitted, I said, that the good of each art is specially
confined to the art?

Yes.

Then, if there be any good which all artists have in common, that is to
be attributed to something of which they all have the common use?

True, he replied.

And when the artist is benefited by receiving pay the advantage is
gained by an additional use of the art of pay, which is not the art
professed by him?

He gave a reluctant assent to this.

Then the pay is not derived by the several artists from their
respective arts. But the truth is, that while the art of medicine
gives health, and the art of the builder builds a house, another art
attends them which is the art of pay. The various arts may be doing
their own business and benefit