Arcesilaus (316/315–241/240 BCE)
Arcesilaus was born in Pitane, a Greek city on the coast of Asia Minor. In Athens, after a period of study with Theophrastus—Aristotle's successor as head of the Peripatos—he joined the Academy, Plato's school, which was then dominated by Crantor, Polemon, and Crates. Arcesilaus succeeded Crates, Polemon's successor, as head of the Academy and was responsible for the school's turn to skepticism. From this point, the skeptical examination of other schools' theories replaced the elaboration of its own positive doctrines as the Academy's principal occupation. This change in the Academy's direction is recognized in the ancient tradition that credits Arcesilaus with founding the second or Middle Academy, which replaced the first or Old Academy and gave way in turn to the third or New Academy of Carneades.
Like Socrates before him and Carneades after him, Arcesilaus wrote nothing, but made his mark in face to face philosophical argument. His practice was not to present views of his own, but instead to invite his interlocutors to put forward their views, which he then subjected to rigorous scrutiny. His method was dialectical: He put questions to his interlocutors from the answers to which he aimed to deduce conclusions at odds with their positions. The effect was to uncover difficulties internal to the interlocutors' positions without committing him to a position of his own. These arguments were conceived by Arcesilaus and his Academic followers as their contribution to argument on both sides of the question, which they regarded as the best way to discover the truth—their ultimate aim. The resemblance to Socrates is unmistakable and was much emphasized by the Academics.
Their principal target was Stoic epistemology. According to Zeno of Citium, the founder of Stoicism and an older contemporary of Arcesilaus's, it is possible for human beings to free themselves entirely from opinion—that is, false or insecure belief—and to attain the kind of knowledge that qualifies as wisdom. In the Socratic tradition, Zeno held that wisdom was identical with virtue and as such the one necessary and sufficient condition for happiness. A necessary condition for knowledge on the Stoic view was the existence of cognitive impressions (kataleptikai phantasiai ). Each of these is a perceptual impression that arises in conditions which both ensure that, by capturing its objects with perfect accuracy, it is true while at the same time imparting to it a character that belongs only to impressions that arise in this way and which human beings can discriminate. According to Stoic epistemology, all knowledge depends in one way or another on cognitive impressions, which is why the cognitive impression is the school's criterion of truth. By restricting one's assent (in the sphere of perception) to impressions with this character, one can avoid ever assenting to a false perceptual impression. If further conditions are satisfied, one can avoid error altogether.
Arcesilaus and the Academics argued that, on any plausible account of it, the character allegedly proper to cognitive impressions was not in fact confined to impressions produced in the specified truth-guaranteeing way, but also belonged to false impressions. As a result, the former, though true, are indistinguishable from the latter and therefore unable to serve as a criterion. It follows on Stoic assumptions about knowledge that nothing can be known. This is the first of the two propositions most closely associated with ancient skepticism. The second—that one ought to suspend judgment—Arcesilaus deduced from the first, together with the Stoic insistence that wisdom is incompatible with mere opinion. Assent to a noncognitive impression (or an impression that does not stand in the proper relation to cognitive impressions), automatically results in opinion, so that, in the absence of cognitive impressions, a wise person can avoid opinion only by suspending judgment entirely.
On a strictly dialectical interpretation of his arguments, Arcesilaus did nothing more than present his Stoic opponents with a set of difficulties. On this view, it was their task either to resolve the difficulties or to abandon or modify the position that had given rise to them. Some ancient authorities held that Arcesilaus's arguments against the possibility of knowledge and in favor of suspension of judgment had implications only for the Stoa and did not prevent him from espousing a form of dogmatic Platonism within the Academy. But according to another, better-founded tradition in the Academy itself, Arcesilaus agreed with Zeno that opinion is utterly alien to wisdom and that it is a grave failing—indeed a sin—to allow assent to run ahead of knowledge. But, according to this tradition, the lesson he drew from the difficulties that he had uncovered in the Stoic position among others, was that he and his opponents were not, or not yet, in a position to assent, secure in the conviction that they were in possession of the truth. In these conditions, suspension of judgment and continued open-minded inquiry were indicated. The skepticism characterized by this attitude was a matter of intellectual honesty and prudence, rather than convinced adherence to the skeptical proposition that nothing can be known. And Arcesilaus, it is told, was careful to maintain that one could not even know that one could not know anything.
The Stoics responded to Arcesilaus by arguing that, if nothing can be known and people are therefore obliged to withhold assent, life becomes impossible, as there can no basis for judgment without a criterion nor any possibility of action without assent. Arcesilaus's answer appears to have been an extension of his first dialectical arguments, for it aimed to show that Stoic epistemology and moral psychology had the resources to explain how a human being may proceed in the absence of cognitive impressions and act without assent. In these conditions, one will be guided by what is reasonable, the notion that the Stoics had used to explain how the wise will act when certainty is not available. It will, for instance, be reasonable to expect a successful voyage if the weather is fair, the crew skilled and so on. Action, on the other hand, requires only that an impression elicit an impulse, which the Stoics used to explain the behavior of nonrational animals and human children, who lack the power of assent.
Arcesilaus's explanation of how action is possible without assent, at least in the form in which it has survived, is sketchy, and it is not clear that it can do justice to the concerns that moved the Stoics and other philosophers to develop their theories in the first place. It plainly does not have the independent appeal of Carneades's theory of probability or his suggestion that assent, as the Stoics conceived it, could be replaced either by qualified assent or a way of following or using impressions that did not entail assent. Nonetheless Arcesilaus's proposals marked the beginning of a long tradition of defending the skepticism as a way of life, of which Carneades's probabilism and Pyrrhonism were later examples.
The example of Arcesilaus continued to inspire members of the Academy until the end of the school's history and thereafter Pyrrhonists, who regarded New Academics such as Carneades as apostates from the true skeptical way but acknowledged a kinship with Arcesilaus.
works giving texts of arcesilaus
Long, A. A., and D. N. Sedley, eds. The Hellenistic Philosophers. 2 vols. Chapters 68–70. Cambridge, U.K.: Cambridge University Press, 1987.
Mette, H. J. "Zwei Akademiker heute: Krantor von Soloi und Arkesilaos von Pitane." Lustrum 26 (1984): 7–94.
studies of arcesilaus
Cooper, John. "Arcesilaus: Socratic and Skeptic." in Knowledge, Nature and the Good, by John Cooper. Princeton, NJ: Princeton University Press, 2004.
Couissin, P. "L'Origine et l'evolution de l'epoche." Revue des études grecques 42 (1929): 373–397.
Couissin, P. "The Stoicism of the New Academy." In The Skeptical Tradition, edited by Myles Burnyeat, 31–63. Berkeley: University of California Press, 1983.
Long, A. A. "Diogenes Laertius, Life of Arcesilaus." Elenchos 7 (1986): 429–449.
Schofield, Malcolm. "Academic Epistemology." In The Cambridge History of Hellenistic Philosophy, edited by Keimpe Algra, Jonathan Barnes, Jaap Mansfeld, and Malcolm Schofield. Cambridge, U.K.: Cambridge University Press, 1999.
Striker, Gisela. "Sceptical Strategies." In Doubt and Dogmatism: Studies in Hellenistic Epistemology, edited by Malcolm Schofield, Myles Burnyeat, and Jonathan Barnes. Oxford: Oxford University Press, 1980.
James Allen (2005)