ARISTOTLE TO AUGUSTINE wrote a Republic, in which he is alleged to have defended incest and cannibalism (LS 67f) Chrysippus diVered from some of his fellows in insisting that a philosopher need not devote himself to scholarship: for a Stoic it was acceptable, indeed praiseworthy, to take part in public life (LS 67w) Scepticism in the Academy During the latter part of the third century Stoic doctrine came under attack from the Academy The academic heirs of Plato began to take their inspiration from Plato’s questioning master, Socrates, and turned to a form of scepticism The leader of the Academy from 273 to 242 was Arcesilaus, a pupil of Pyrrho of Elis, a man often regarded as the founder of philosophical scepticism Pyrrho, an older contemporary of Epicurus, who had served as a soldier in Alexander’s army, taught that nothing could be known and, accordingly, wrote no books It was Arcesilaus and another of Pyrrho’s pupils, Timon, who brought scepticism to Athens in the early years of the third century Timon denied the possibility of Wnding any self-evident principles to serve as the foundation of sciences In the absence of such axioms, all lines of reasoning must be circular or endless The scepticism of Timon and Arcesilaus came to fruition, in a modiWed and more sophisticated form, with the work of Carneades, who headed the Academy from 155 to 137 Like Pyrrho, Carneades left no writings, but his arguments were recorded by a pupil who attended his highly popular lectures They have come down to us principally through the good oYces of Cicero, who was once taught by Carneades’ pupil Philo In 155 Carneades was sent by Athens, along with a Stoic and a Peripatetic philosopher, on an embassy to Rome During this embassy he displayed his rhetorical skill by arguing on successive days for and against justice Cato the Roman Censor, who heard his performance, sent him packing as a subversive inXuence (LS 68m) Arcesilaus criticized the Stoics because they had claimed to found their search for truth upon mental impressions incapable of falsehood: there were, he argued, no such impressions Carneades too attacked Stoic epistemology, and taught that probability, not unattainable truth, should be the guide to life Though not himself an atheist, he ridiculed mercilessly both the traditional pantheon and Stoic pantheism His arguments against 100