  We explain Reidian conception by contrast with the Way of Ideas. First, Reid presupposes that the mind has an irreducible capacity for intentional conception in which our mental states are uniquely about specific objects. This faculty cannot be explained in terms of further non-intentional states. How intentional conception can be explained is mysterious—Reid is well aware of this. Yet if “we were unable to give any account how we first got the conception of power, this would be no good reason for denying that we have it” (Reid 2001, “Of Power,” 5). In a contrasting methodological move, Hume suggests that intentional content through ideas is built up from the operation of the laws of association—contiguity in time and space, resemblance and perceived causation—working upon impressions and images in the mind (see Treatise 1.1.1.7, 4; 1.2.3.2, 33; 2.1.11.8, 319; Enquiry 7.2.6, 74).