roved of by Arcesilas, for it
confirmed both his first and second proposition. But Carneades sometimes
granted that minor premiss, that the wise man did at times assent: then it
followed that he also was at times guided by opinion; which you will not
allow; and you are right, as it seems to me: but the first proposition,
that the wise man, if he expresses assent, must also be guided by opinion,
is denied by the Stoics and their follower on this point, Antiochus.

For they say that they can distinguish what is false from what is true,
and what cannot be perceived from what can. But, in the first place, even
if anything can be perceived, still the very custom of expressing assent
appears to us to be perilous and unsure. Wherefore, as it is plain that is
so faulty a proceeding, to assent to anything that is either false or
unknown, all assent must rather be removed, lest it should rush on into
difficulties if it proceeds rashly. For what is false is so much akin to
what is true, and the things which cannot be perceived to those which can,
(if, indeed, there are any such, for we shall examine that point
presently,) that a wise man ought not to trust himself in such a hazardous
position.

But if I assume that there is actually nothing which can be perceived, and
if I also take what you grant me, that a wise man is never guided by
opinion, then the consequence will be that the wise man will restrain all
assent on his part; so that you must consider whether you would rather
have it so, or let the wise man sometimes form opinions. You do not
approve of either, you will say. Let us, then, endeavour to prove that
nothing can be perceived; for that is what the whole controversy turns
upon.

XXII. But first I must say a few words to Antiochus; who under Philo
learnt this very doctrine which I am now defending, for such a length of
time, that it is certain that no one was ever longer studying it; and who
wrote on these subjects with the greatest acuteness, and who yet attacked
it in his old age with no less energy than he had defended it in his
youth. Although therefore he may have been a shrewd arguer, as indeed he
was, still his authority is diminished by his inconsistency. For what day,
I should like to know, will ever dawn, which shall reveal to him that
distinctive characteristic of what is true and what is false, of which for
so many years he denied the existence? Has he devised anything new? He
says the same that the Stoics