Casey Perin

According to the dogmatic interpretation of the Academic philosopher Arcesilaus, he held, among other philosophical views, the view that nothing can be known and the view one ought to suspend judgment about everything. According to the dialectical interpretation, Arcesilaus’ scepticism consists not in any philosophical view he holds — for he holds none — but in his practice of suspending judgment about all, or at least all philosophical, matters. This chapter argues that these two rival interpretations constitute an interpretative dilemma: neither interpretation is adequate and there is no third option. Arcesilaus either did or did not have philosophical views. If he did, as the dogmatic interpretation claims, then he is inconsistent and there is no clear way to rescue him from this inconsistency. If Arcesilaus did not have philosophical views, then the practice of universal suspension of judgment in which his scepticism is supposed to consist is inexplicable. The upshot is that we have not yet managed to make sense of Arcesilaus as a philosopher. It is shown that we can do so, if we can, only by working through those philosophical issues that the dogmatic and dialectical interpretations of Arcesilaus raise but that their advocates have not resolved or even much discussed.

The Book Symposium consists of four texts. In the first, the author summarizes his book, presenting its main contribution and giving an overview of the chapters. In the second, Stéphane Marchand, after highlighting the methodological affinity between the book and his training in France, discusses the new division of the initial chapters of the Outlines of Pyrrhonism and the more robust interpretation of the notion of skeptical logos. In the third text, Casey Perin also insists on this last point. In his view, Smith correctly raises a central issue in Sexto’s interpretation and draws attention to a crucial but little-studied passage. However, Smith would not have been able to explain how skepticism could be normative without dogmatism adequately. The last text is the author's response to the objections raised.

In this dissertation I examine the ways in which the central arguments of ancient scepticism exploit normative aspects of the conception of rationality endorsed by the sceptic's opponent. I look first at the long and vigorous debate between the Stoics and the Academic sceptics. The Stoics argued that the ideals of wisdom and virtue require that a person assents only to cognitive impressions, and the Academics claimed to have shown that the Stoics are by their own norms for assent committed to suspending judgment about all matters of fact. I offer a new interpretation of the Stoic doctrine of cognitive impressions, and I argue that my interpretation of Stoic cognitive impressions places us in a better position to answer important philosophical questions about whether and how the Academics' sceptical attack against the Stoic view succeeds. The Pyrrhonian sceptic appears to operate without any norms for assent or any commitment to rationality. I argue that here, at least, appearances are deceptive. The Pyrrhonist regards both herself and her interlocutor as rational creatures with an interest in truth. I argue that the Pyrrhonist therefore shares with her dogmatic interlocutor a complex and substantive normative principle concerning inferences from claims about how things appear to claims about how things really are. I argue that the Pyrrhonist's sceptical strategy, including the appeal to conflicting appearances, exploits this principle to bring about suspension of judgment in both the Pyrrhonist herself and her interlocutor. The Pyrrhonist's commitment to this substantive normative principle, I argue, requires that we reinterpret both the nature of Pyrrhonian inquiry and the assumption about the formation of beliefs that underwrites it. With this in mind I turn, finally, to the naturalistic investigation of the causes of our beliefs that Hume undertakes. I argue that Hume's treatment of scepticism in the Treatise presents a strong challenge to the project of Pyrrhonian scepticism because it shows how a person can reach a sceptical conclusion about her own beliefs without suspending judgment or even withdrawing the claim that her beliefs are reasonable

According to Sextus Empiricus, the Skeptic suspends judgment in response to equipollence. This fact has two significant implications. First, the Skeptic has at most indirect control over his suspension of judgment and so does not suspend judgment at will. Second, the skeptic accepts the norm of truth for belief. This is a norm according to which one ought to believe that p only if p is true. However, there are passages in the Outlines of Pyrrhonism that imply the Skeptic accepts the norm of utility for belief. This is a norm according to which one ought to believe that p only if the belief that p promotes one’s tranquility. I first argue that if the Skeptic suspends judgment in response to equipollence, then a pragmatic reason can’t be the reason for which the Skeptic suspends judgment. I then argue that the norms of truth and utility for belief are incompatible just in the sense that the acceptance of the one precludes the acceptance of the other. If Sextus describes the Skeptic as accepting both of these norms for belief, as I argue he does, his conception of Skepticism in the Outlines is not coherent.

The Academics offered an argument from twins or perceptually indiscernible objects and an argument from dreams or madness in support of the indiscernibility thesis: that every true perceptual impression is such that some false impression just like it is possible. I claim that these arguments, unlike modern sceptical arguments, are supposed to establish mere counterfactual rather than epistemic possibilities. They purport to show that for any true perceptual impression j, there are a number of alternative causal histories j might have had which would not have resulted in any change in the way in which j represents its object