Academic Scepticism 267
Cicero Academica 2.28 [III-6]
Hence arose the demand made just now by Hortensius, that you
[sceptics] should at least concede that the wise man has grasped that
nothing can be grasped. But Antipater [the Stoic] demanded the very
same thing, and said that it was consistent for him who affirmed that
nothing could be perceived to say that [at least] this one thing could be
perceived, even if other things could not. Carneades argued against him
with greater acuity: for, he said that, far from being consistent, it was
in fact totally self-contradictory. For he who denies that there is anything
that can be grasped makes no exceptions; therefore, it is necessary that
not even [the claim that nothing can be grasped] can in any way be grasped
and perceived, since it has not been excepted [from the general claim].
Cicero Academica 2.40-42 [III-7]
- But now let us look at the opposing arguments usually advanced
by the other side [i.e., the Academics]. But first you can become ac-
quainted with what are, as it were, the foundations of their entire system.
So first of all they put together a sort of craft dealing with what we call
presentations, and they define their character and types, and in particular
they [define] what sort of thing can be perceived and grasped, at as great
a length as the Stoics do. Then they elaborate the two propositions which,
as it were, constitute this entire investigation. [1] When there are things
which are so presented that other things can be presented in the same
way, and that there is no difference between [the two presentations], it
is not possible that the one group should be perceived and the other not.
[2] However, [they say that] there is no difference, not just if they are
of the same quality in all respects, but even if they cannot [in fact] be
distinguished [by the perceiver]. When these premisses are laid down,
the whole issue is contained in one argument; and the argument is put
together as follows. Some presentations are true, some false; what is false
cannot be perceived; but every true presentation is such that there can
be a false presentation of the same quality; and with presentations which
are such that there is no difference between them it cannot happen
that some can be perceived while others cannot; therefore, there is no
presentation which can be perceived. - They think that of the premisses they assume in order to generate
the desired conclusion, two will be granted to them (and in fact no one
does reject these two); these are, [first] that false presentations cannot
be perceived, and the other is that with presentations between which
there is no difference it is not possible that some should be such as to