Mediate Perception and the Likeness Principles: George Berkeley’s Refutation of the Indirect Realist Theory of Perception

Abstract

Scholars note that George Berkeley makes two arguments from the likeness principle in his polemic against a resemblance-based theory of indirect realism (RIR, henceforth).1 Indirect realism is the theory of perception according to which veridical perception is an immediate perceptual awareness of sense data, which are wholly phenomenal, mental qualities with representative content that gives us mediate perceptual access to material objects.2 RIR is the conjunction of indirect realism and the claim that sense data represent material objects insofar as they resemble one another.3 The first version of the likeness principle is characterized by the claim that ‘an idea can be like nothing but an idea’ (LP1, henceforth), and the second by the claim that ‘something sensible cannot be like something insensible’ (LP2, henceforth). The standard interpretation of Berkeley’s intent for the argument from LP1 is to show that RIR is by necessity false. If material objects are not ideas, and if only ideas can resemble ideas, then ideas cannot resemble material objects, and resultantly RIR must be false. The standard interpretation of Berkeley’s intent for the argument from LP2 is also to show that RIR is by necessity false. If material objects are not sensible, then they cannot resemble ideas, which are by their nature sensible, and resultantly RIR must be false. (From Introduction)