Note 3 — Chapter XXIII · THE NEW ACADEMY.

This connection of the New Academy with Stoicism can be proved in the case of its first founder,3 Arcesilaus.4 The doubts of this philosopher are directed not only to knowledge derived from the senses, but to rational knowledge as well.5 The principal object of his attack was, however, the Stoic theory of irresistible impressions;6 and in overthrowing that theory Arcesilaus, it would seem, believed he had exploded every possibility of rational knowledge; for the Stoic appeal to the senses he regarded as the only possible form of a theory of knowledge, and the theories of Plato and Aristotle he ignored altogether. Indeed, no peculiar arguments against knowledge are referred to him. The old sceptical arguments of Plato and Socrates, of Anaxagoras, Empedocles, Democritus, Heraclitus, and Parmenides, are repeated,7 all of which apply only to the knowledge of the senses, and not to rational knowledge. Nevertheless, Arcesilaus aimed at overthrowing the latter along with the former.8 The opinion that he only used doubt to prepare for or to conceal genuine Platonism,9 is opposed to all credible authorities. It appears, however, established that he deemed it unnecessary to refute the theory of a knowledge existing independently of the senses.