Abstract

In the final quarter of “Of scepticism with regard to the senses,” Hume uses Pyrrhonian experiments to discredit sensory beliefs, even if only “extravagant” sceptics attempt to embrace the conclusion. By means of a close comparison with Hume’s discussion of scepticism concerning reason, this chapter argues that he uses our incapacity to disbelieve sensory verdicts as evidence in support of his model of sensory belief. Where Locke has a view of consciousness and reflection that leaves him as a “double existence” theorist, with perceptions being different in kind from objects, Hume thinks sensation involves a single existence—an impression—and the reactions of the imagination. The chapter shows that Humean reflection involves the formation of secondary ideas of mental states, where the imagination’s reactions yield the belief in the introspection-independence of the observed perceptions. Thus an attempt to use reflection to attack sensation ends up undermining itself.