  The second problem with the interpretation of Arcesilaus’ skepticism in Academica 2.66–7 &amp; 2.77 is that it risks self-defeat. The problem lies not in knowing that nothing can be known, since, on one account (Cicero Academica 1.45), Arcesilaus, unlike Socrates, explicitly disclaimed such second-order knowledge. It lies rather in believing that nothing can be known in conjunction with the belief that it is irrational to hold opinions in the absence of knowledge. If the former is true, it is irrational (and so one ought not) to believe the premises of the arguments that support both inapprehensibility and universal suspension.