=71.= The followers of Plato were known as the ‘Academics’: amongst them we must distinguish between the members of the ‘old Academy,’ as Cicero terms them[13], and those who followed the innovations of Arcesilaus. The old Academy chiefly developed the ethical side of Plato’s teaching, finding that the path of virtue is indicated by the natural capacities of the individual. Thus XENOCRATES of Chalcedon (396-314 B.C.) taught that each man’s happiness resulted from the virtue proper to him (οἰκεία ἀρετή)[14]; whilst POLEMO of Athens (head of the school 314-270 B.C.) is said by Cicero to have defined it as consisting in ‘virtuous living, aided by those advantages to which nature first draws us,’ thereby practically adopting the standard of Aristotle[15]. The teaching of Polemo had a direct influence upon that of Zeno the founder of Stoicism. But with the first successes of Stoicism the Academy revived its dialectical position, in strong opposition to the dogmatism of the new school. ARCESILAUS of Pitane in Aeolia (315-240 B.C.) revived the Socratic cross-examination, always opposing himself to any theory that might be propounded to him, and drawing the conclusion that truth could never be certainly known[16]. Life must therefore be guided by considerations of probability, and the ethical standard is that ‘of which a reasonable defence may be made[17].’ This sceptical attitude was carried still further by CARNEADES of Cyrene (214-129 B.C.), whose acute criticism told upon the Stoic leaders of his time, and forced them to abandon some of their most important positions. From this time a reconciliation between the two schools set in[18]. [Sidenote: The Peripatetics.]