 The contribution for which Carneades is best known, however, came in reply to the Stoics’ counter-argument in defense of the cognitive impression. In response to their contention that, without cognitive impressions, human beings would lack any basis for action or inquiry Carneades argued that such a basis could be found in so-called probable impressions (from probabilis, that which lends itself to or invites approval, Cicero’s Latin for Greek “pithanos,” persuasive) (see Allen, 1994; Obdrzalek, 2006; Reinhardt, 2018). The theory of probable impressions went far beyond anything Arcesilaus had said and had an independent appeal which Arcesilaus’ response to the same challenge lacked. Carneades’ defense of this theory is a main reason why he was thought to have departed from or moderated the stricter skepticism thought to have been espoused by Arcesilaus and the Middle Academy (S.E. Pyrrhoneae hypotyposes [henceforward PH] 1.227–30; M 7.166–89 = L&amp;S 69DE). It seemed to be complemented by the line he sometimes defended on opinion, and that some of his successors took for his considered opinion, according to which assent to non-cognitive impressions and the opinions to which it gives rise are compatible with wisdom (Acad. 2.59, 67, 78). But the interpretation of Carneades championed by Clitomachus, according to which the wise will refrain from assent and so avoid opinion, also relied on probability as the basis for an alternative form of approval (Acad. 2.99-100, 104-3).