interest of a man's friend is as dear to him as his own; others, on
the other hand, contend that every man has a greater regard for his own.
Yet these latter confess that it is inconsistent with justice, for which
we seem to be born, to take anything from another for the purpose of
appropriating it to oneself. But philosophers of this school which I am
speaking of, never approve of either friendship or justice being exercised
or sanctioned for the sake of its usefulness: for they say that the same
principles of usefulness may, at times, undermine or overturn them. In
truth, neither justice nor friendship can have any existence at all,
unless they be sought for their own sake. They contend also that all
right, which has any pretence to the name and appellation, is so by
nature; and that it is inconsistent with the character of a wise man, not
only to do any injustice to any one, but even to do him any damage. Nor is
it right to make such a league with one's friends as to share in all their
good deeds, or to become a partner in every act of injustice; and they
argue, with the greatest dignity and truth, that justice can never be
separated from usefulness: and that whatever is just and equitable is also
honourable; and, reciprocally, that whatever is honourable must be also
just and equitable.

And to those virtues which we have discussed, they also add dialectics and
natural philosophy; and they call both these sciences by the name of
virtues: one, because it has reason, so as to prevent our assenting to any
false proposition, or being even deceived by any plausible probability;
and to enable us to maintain and defend what we were saying about good and
evil. For without this act they think that any one may be led away from
the truth and deceived; accordingly, if rashness and ignorance is in every
case vicious, this power which removes them is properly named virtue.

XXII. The same honour is also attributed to natural philosophy, and not
without reason, because the man who wishes to live in a manner suitable to
nature, must begin by studying the universal world, and the laws which
govern it. Nor can any one form a correct judgment of good and evil
without being acquainted with the whole system of nature, and of the life
of the gods also, and without knowing whether or not the nature of man
agrees with universal nature. He must also have learnt the ancient rules
of those wise men who bid men yield to the times, and obey God