I explained just now, on the testimony of Clitomachus, in what manner Carneades intended those statements to be taken. Hear now, how the same things are stated by Clitomachus in that book which he dedicated to Caius Lucilius, the poet, after he had written on the same subject to Lucius Censorinus, the one, I mean, who was consul with Marcus Manilius; he then used almost these very words; for I am well acquainted with them, because the first idea and arrangement of those very matters which we are now discussing is contained in that book. He then uses the following language--
"The philosophers of the Academy are of opinion that there are differences between things of such a kind that some appear probable, and others the contrary. But that it is not a sufficient reason for one's saying that some of these can be perceived and that others cannot, because many things which are false are probable; but nothing false can be perceived and known. Therefore, says he, those men are egregiously wrong who say that the Academics deny the existence of the senses; for they have never said that there is no such thing as colour, or taste, or sound; the only point they argue for is, that there is not in them that peculiar characteristic mark of truth and certainty which does not exist anywhere else."
And after having explained this, he adds, that there are two senses in which the wise man may be said to suspend his assent: one, when it is understood that he, as a general rule, assents to nothing; the other, when he forbears answering, so as to say that he approves or disapproves of anything, or, so as to deny or affirm anything. This being the case, he approves of the one sense, so as never to assent to anything; and adheres to the other, so as to be able to answer yes, or no, following probability whenever it either occurs or is wanting. And that one may not be astonished at one, who in every matter withholds himself from expressing his assent, being nevertheless agitated and excited to action, he leaves us perceptions of the sort by which we are excited to action, and those owing to which we can, when questioned, answer either way, being guided only by appearances, as long as we avoid expressing a deliberate assent. And yet we must look upon all appearances of that kind as probable, but only those which have no obstacles to counteract them. If we do not induce you to approve of these ideas, they may perhaps be false, but they certainly do not deserve odium. For we are not depriving you of any light; but with reference to the things which you assert are perceived and comprehended, we say, that if they be only probable, they appear to be true.