 (i) The Stoic-Academic Debate. Chrysippus, the third major Stoic (after Zeno and Cleanthes), and his student Diogenes of Babylon, revise Zeno’s epistemology, defending it against Arcesilaus’ arguments (Brittain 2006, xiii). In response to their arguments, Carneades continues the exchange with the Stoics that Arcesilaus began (SE M 7.402–10). His first move addresses the link between mental states and action. People in states of madness, he argues, act just as easily and naturally on their impressions as other people, even those who act on cognitive impressions (if there are any). From the point of view of exhibited behavior, there does not seem to be a difference: any and all impressions, even those the Stoics think clearly arise from something that is not, are in all respects relevant to action completely on a par. Cognitive impressions, if there are any, have no superiority.