CRITIAS: No.

SOCRATES: It is not therefore necessary that the means by which we obtain
what is useful for a certain object should always be useful for the same
object: for it seems that bad actions may sometimes serve good purposes?
The matter will be still plainer if we look at it in this way:--If things
are useful towards the several ends for which they exist, which ends would
not come into existence without them, how would you regard them? Can
ignorance, for instance, be useful for knowledge, or disease for health, or
vice for virtue?

CRITIAS: Never.

SOCRATES: And yet we have already agreed--have we not?--that there can be
no knowledge where there has not previously been ignorance, nor health
where there has not been disease, nor virtue where there has not been vice?

CRITIAS: I think that we have.

SOCRATES: But then it would seem that the antecedents without which a
thing cannot exist are not necessarily useful to it. Otherwise ignorance
would appear useful for knowledge, disease for health, and vice for virtue.

Critias still showed great reluctance to accept any argument which went to
prove that all these things were useless. I saw that it was as difficult
to persuade him as (according to the proverb) it is to boil a stone, so I
said: Let us bid 'good-bye' to the discussion, since we cannot agree
whether these things are useful and a part of wealth or not. But what
shall we say to another question: Which is the happier and better man,--he
who requires the greatest quantity of necessaries for body and diet, or he