 Against a position that denies that certainty is attainable, Lucullus argues that intellectual enquiry, which aims at proof, will be hamstrung, since proof requires certainty (2.26). Moreover, the sceptic’s refusal to allow that there can be ‘cataleptic’ impressions – the Stoic technical term for impressions that can be grasped with certainty – will subject the sceptic to the charge of inconsistency (cf. 2.44): the sceptic holds that nothing can be grasped with certainty, but surely the claim that ‘nothing can be grasped with certainty’ must itself be graspable with certainty, or else the sceptic position lacks firm foundation.