Publications and Under Review


The challenges of the Modes of Agrippa (2016) Apeiron 49 (4) 409-435.

The standard “gladiatorial” interpretation of the Modes of Agrippa has undergone several recent attacks. Scholars have criticized it because it seems to portray the skeptic as a dogmatist about logical support and because it does not treat all five Modes as part of the system. Although some have attempted to patch up the standard interpretation to address these issues, I raise a further problem: The gladiatorial interpretation cannot make sense of the skeptic using the Modes on herself, to suspend her own judgment. In light of these problems, I propose a fresh interpretation: The Agrippan Modes should be understood, not as arguments (or argument forms), but as types of dialectical challenge that the skeptic can use in an endless inquiry into any dogmatic position.


Skeptical διαφωνία

When Sextus Empiricus distinguishes between dogmatic philosophers and skeptics in the opening section of his Outlines of Pyrrhonism (PH), he says that the dogmatist claims to have found the answer, while the skeptic keeps investigating (PH I 1). A few lines later he also says that the skeptic suspends judgment in the face of oppositions (PH I 8), and that the skeptic does not assent to anything unclear (PH I 13). Many scholars have found the conjunction of these passages puzzling: How can you keep investigating once you have decided that the appropriate response to a disagreement is the suspension of judgment? In this paper, I explain how the skeptic's investigative activity harmonizes with the suspensive response due to a certain practical norm that governs the skeptic's reaction to disagreement, namely that the skeptic suspends judgment once he is aware of a disagreement before he begins to investigate what can be said on behalf of either side. I claim that this norm marks the fundamental difference between the skeptics and the dogmatists, who typically stick to their beliefs while they look into the issue. I point out and discuss those passages where Sextus suggests that he holds the norm that I claim he holds. I also show how my interpretation helps to explain several puzzling features of Pyrrhonian philosophy, including the idea that one could both suspend judgment and continue investigating.

On the cosmological argument for the swerve (De Rerum Natura II 217-225)

Lucretius offers two arguments for the existence of the swerve, the notorious doctrine that atoms randomly change direction from time to time as they move. Most scholarly attention has focused on the role that the swerve plays in his (and Epicurus') account of free will. Less has been written on the so-called Cosmological Argument for the swerve, that is, the role that the swerve plays in bringing about atomic collisions and ultimately the universe as we observe it. Most commentators who do address the Cosmological Argument do little more than repeat what Lucretius says, namely that if there were no swerve, there would be no collisions. Some scholars quickly dismiss the argument as a poor one, usually on the grounds that, given the Epicurean doctrine that atoms have always been interacting with each other, there can be no first collision, and thus no need for the swerve on that basis. I defend a fairly literal interpretation of Lucretius' argument for the swerve. I think that Epicurus posited the swerve because he was concerned that without it, his physics implied that all atoms, at some point in the past, must have been falling straight downward at an equal rate without touching each other. If the Epicurean system implies the necessary occurrence of this “atomic rain,” then nothing should now exist. But our kosmos does exist, so there is a problem with Epicurean physics without the swerve. I contend that Epicurus (or perhaps later Epicureans) posited the swerve – in part – to solve this problem.