Nor have you, O Lucullus, omitted that other objection of Antiochus (and,
indeed, it is no wonder, for it is a very notorious one,) by which he used
to say that Philo was above all things perplexed. For when one proposition
was assumed, that some appearances were false, and a second one that there
was no difference between them and true ones, he said that that school
omitted to take notice that the former proposition had been granted by
him, because there did appear to be some difference between appearances;
but that that was put an end to by the second proposition, which asserted
that there was no difference between false and true ones; for that no two
assertions could be more contradictory. And this objection would be
correct if we altogether put truth out of the question: but we do not; for
we see both true appearances and false ones. But there is a show of
probability in them, though of perception we have no sign whatever.

XXXV. And I seem to myself to be at this moment adopting too meagre an
argument; for, when there is a wide plain, in which our discourse may rove
at liberty, why should we confine it within such narrow straits, and drive
it into the thickets of the Stoics? For if I were arguing with a
Peripatetic, who said "that everything could be perceived which was an
impression originating in the truth," and who did not employ that
additional clause,--"in such a way as it could not originate in what was
false," I should then deal plainly with a plain man, and should not be
very disputatious. And even if, when I said that nothing could be
comprehended, he was to say that a wise man was sometimes guided by
opinion, I should not contradict him; especially as even Carneades is not
very hostile to this idea. As it is, what can I do? For I am asking what
there is that can be comprehended; and I am answered, not by Aristotle, or
Theophrastus, or even Xenocrates or Polemo, but by one who is of much
later date than they,--"A truth of such a nature as what is false cannot
be." I find nothing of the sort. Therefore I will, in truth, assent to
what is unknown;--that is to say, I will be guided by opinion. This I am
allowed to do both by the Peripatetics and by the Old Academy; but you
refuse me such indulgence, and in this refusal Antiochus is the foremost,
who has great weight with me, either because I loved the man, as he did
me, or because I consider him the most refined and acute of all the
philosophers of our age.