[4] Hyp. I. 231.
[5] Hyp. I. 235.
During all the chequered history of the Academy the dormant idealism was there, underlying the outward development. Although during the time of Arcesilaus and Carneades the difference was so slight as to seem a mere matter of form of expression, yet the different foundations on which the two schools stood was always recognisable. On the one hand there was the germ of idealism which was destined to awake to a new life, and on the other, the attempt at absolute negation which was to result in the final extinction of Pyrrhonism. We find in both, it is true, especially in the time of Arcesilaus, the aim of ἐποχή. [1] Both placed great weight on ἰσοσθένεια, or the equal value of opposing arguments. [2] The foundation of the ἐποχή was, however, different in the two cases. Arcesilaus founded his on dialectic, while Pyrrho's was empirical.
[1] Hyp. I. 232.
[2] Diog. IX. 73; Hyp. II. 130; III. 65.
The Pyrrhonean believed that ideas give us no knowledge of the outer world; the Academic Sceptic believed that we cannot distinguish between true and false ideas, so such knowledge is impossible. The Pyrrhonean denied that truth could exist in ideas because of their contradictory nature, and consequently the existence of all truth, μηδὲν εἶναι τῇ ἀληθείᾳ ἐπὶ πάντων. [1] The Academic Sceptic granted that the truth was possibly contained in ideas, but affirmed that it could never be known to us. The Pyrrhoneans prided themselves on still being seekers, for although ordinary ideas are too contradictory to give knowledge of the outer world, they did not deny that such knowledge might be possible, but simply suspended the judgment regarding it. To the Pyrrhonean the result corresponded to the method. All ideas thus far known revealed nothing of the truth, therefore he still sought. The Academician tried logically to prove that the truth is impossible to find. It is the relation of the dialectician to the empiricist, and the two varieties of Scepticism are explained by their difference in origin. In Pyrrhonism there was no constructive element. In the Academic Scepsis such an element was found throughout all its history in the theory of Probability. Arcesilaus himself laid great stress upon this doctrine, which Sextus carefully shows us[2] is utterly inconsistent with Pyrrhonism. Arcesilaus plainly teaches that, having suspended one's judgment in regard to matters of knowledge, one should control his choices, his refusals, and his actions by the probable.[3]
[1] Diog. IX. 11, 61.
[2] Hyp. I. 229.
[3] Compare Maccoll Op. cit. 39.
After Antiochus introduced Eclecticism into the Academy, Pyrrhonism was the only representative of Greek Scepticism, and it flourished for over two centuries after our era, and then also disappeared, no more to exist as a regular philosophical school.