 The Stoics, of course, came up with plenty of sophisticated counter-arguments to the criticisms of the cognitive impression, to which the Academics devised equally subtle responses. But one argument in particular seems to have seriously troubled the Academic students of Carneades: the Stoic “inactivity” objection. This was a very simple practical reductio, connected to the corollary argument given above: if the Academics were right it would be impossible to act at all (let alone well), since voluntary action depends on beliefs and thus on assent (see, e.g., Cicero Ac. 2.24–5 and 2.34–7). But since action (indeed, good action) is possible, the Academics must be mistaken. The later Academics saw three ways in which they could respond to this counter-argument without giving up their arguments against cognitive impressions. They could: