[1949. In Collier’s Encyclopedia. New York: P.F. Collier and Son.]
CARNEADES (c. 214-129 B.C.). Greek philosopher, the founder of the New Academy, and an able skeptical opponent of the Stoics, was born at Cyrene. He studied with Diogenes the Stoic, and in 155 accompanied him and Critolaus the Peripatetic to Rome on a political mission. So great was the enthusiasm for speculation that he aroused among the Roman youth that Cato the Elder insisted upon his banishment from the city.
Carneades taught that neither sensation nor reason furnishes a criterion of truths, that there is no infallible distinction between a true and a mistaken idea. Some ideas, however, are more probable than others, and this fact saves skepticism from denying the possibility of reasonable conduct. Carneades’ interest in morality is also seen in his attack on the Stoic doctrine of fate, for he argued that the denial of free will makes morality meaningless. His writings have not been preserved, and Cicero is our chief source of information. G.H.CL.