 Like Socrates, Arcesilaus did not write anything. His views must be unearthed from Sextus’ comparisons between Pyrrhonian and Academic skepticism, from Cicero’s discussions in the Academica, and from a range of shorter (and sometimes hostile) reports. Major themes in Arcesilaus’ philosophy are (i) his dialectical method, (ii) discussion of whether there is a criterion of truth, and (iii) his defense of the skeptic’s ability to act.