69. Sceptical Schools; The Later Academies. -- The Sceptics of the third and second centuries assign as the only aim of philosophy the search for happiness; and happiness for them, as for the Stoics and Epicureans, consists in the soul's rest, -- ataraxy. If they deny the possibility of certain knowledge, it is because in their view speculative certitude is not indispensable for happiness.

Three Sceptic Schools appeared during this period: (1) The Pyrrhic School founded by PYRRHO OF ELIS (about 360-270), which, however, was of short duration and little influence. (2) The Second or Middle Academy, established by ARCESILAUS OF PITANE (315-240), who gave the ancient Platonic school an inclination towards scepticism and concluded like Pyrrho that, certitude being an illusion, epochê or the suspension of the exercise of the judicial faculty is the only legitimate attitude for the philosopher. (3) The Third or New Academy, founded a century later by CARNEADES OF CYRENE (213-129), who developed the scepticism of the Academy and amassed objections against Dogmatism in general and Stoicism in particular. Following Arcesilaus, Carneades endeavours to find in the probability of certain representations, a sufficient but indispensable motive of conduct.