Note 10 — Chapter XXIII · THE NEW ACADEMY.

The Stoic arguments in favour of irresistible impressions Arcesilaus met by asserting that an intermediate something between knowledge and opinion, a kind of conviction common to the wise and the unwise, such as the Stoic κατάληψις, is inconceivable; the wise man’s conviction is always knowledge, that of the fool is always opinion.10 Going then farther into the idea of φαντασία καταληπτική, he endeavoured to show that it contained an internal contradiction; for to conceive (κατάληψις) is to approve (συγκατάθεσις), and approval never applies to sensation, but only to thoughts and general ideas.11 Lastly, if the Stoics regarded force of conviction as the distinctive mark of a true or irresistible conception, and as belonging to it in distinction from every other, the Sceptic rejoined that such conceptions do not exist, and that no true conception is of such a nature, but that a false one may be equally irresistible.12 If no certainty of perception is possible, no knowledge is possible.13 And since the wise man—for on this point Arcesilaus agrees with the Stoics—must only consider knowledge, and not opinion, nothing remains for him but to abstain from all and every statement, and to despair of any certain conviction.14 It is therefore impossible to know anything, nor can we even know for certain that we do not know anything.15 It was quite in accordance with this theory for Arcesilaus to lay down no definite view in his lectures, but only to refute the views of others.16 Even his disparaging remarks on dialectic,17 supposing them to be genuine,18 are not at variance with this conduct. He might consider the arguments of the Stoics and the sophisms of the Megarians as useless, whilst, at the same time, he was convinced that no real knowledge could be attained by any other means. He might even have inferred from their sterility, that thought leads to truth quite as little as the senses. There is no real difference between the result at which he arrived and that of Pyrrho.19