  We are informed about Antiochus’ case against Academic skepticism by Cicero’s Academica, substantial parts of which have survived intact. Antiochus seems to have followed the Stoics, who produced a substantial literature defending their position and attacking the Academy’s probabilistic alternative, but also to have added some elements of his own to the argument (cf. Striker 1997). He defended the veracity of the senses. He seems to have argued that in order even to possess a concept of the truth we must indisputably apprehend some truths in a way that is possible only if there are cognitive impressions (Acad. 2.33). He argued that probable impressions are a wholly inadequate substitute for cognitive impressions (Acad. 2.35–6), so that the charge that by abolishing the cognitive impression (as they think) the Academics deprive human beings of a basis for action stands (Acad. 2.31, 33, 54, 62, 102–3, 110). And he argued that, in maintaining the skeptical position, the Academics must take themselves to know at least one thing, viz., that nothing can be known (Acad. 2.28–9, 109; cf.  Burnyeat 1997).