eved a Herculean labour when, as if it had been a
savage and formidable monster, he extracted assent, that is to say, vague
opinion and rashness, from our minds,--yet, supposing that part of the
defence is wholly omitted, what will hinder the action of that man who
follows probability, without any obstacle arising to embarrass him? This
thing of itself, says he, will embarrass him,--that he will lay it down,
that even the thing he approves of cannot be perceived. And that will
hinder you, also, in sailing, in planting, in marrying a wife, in becoming
the parent of children, and in many things in which you follow nothing
except what is probable.

And, nevertheless, you bring up again that old and often repudiated
objection, to employ it not as Antipater did, but, as you say, in a closer
manner. For you tell us that Antipater was blamed for saying, that it was
consistent in a man who affirmed that nothing could be comprehended, to
say that at least this fact of that impossibility could be comprehended;
which appeared even to Antiochus to be a stupid kind of assertion, and
contradictory to itself. For that it cannot be said with any consistency
that nothing can be comprehended, if it is asserted at the same time that
the fact of the impossibility can be comprehended. He thinks that
Carneades ought rather to be pressed in this way:--As the wise man admits
of no dogma except such as is comprehended, perceived, and known, he must
therefore confess that this very dogma of the wise man, "that nothing can
be perceived," is perceived; as if the wise man had no other maxim
whatever, and as if he could pass his life without any. But as he has
others, which are probable, but not positively perceived, so also has he
this one, that nothing can be perceived. For if he had on this point any
characteristic of certain knowledge, he would also have it on all other
points; but since he has it not, he employs probabilities. Therefore he is
not afraid of appearing to be throwing everything into confusion, and
making it uncertain. For it is not admissible for a person to say that he
is ignorant about duty, and about many other things with which he is
constantly mixed up and conversant; as he might say, if he were asked
whether the number of the stars is odd or even. For in things uncertain,
nothing is probable; but as to those matters in which there is
probability, in those the wise man will not be at a loss what to do, or
what answer to give.