Abstract: The thesis that the mind cannot directly apprehend features of the physical world — what Thomas Reid calls the Way of Ideas — is a staple of Early Modern philosophical tradition. This commitment to the direct awareness of, and only of, mental representations unifies the otherwise divergent philosophical systems of Rationalists and Empiricists. Thomas Reid battles against this thesis on many fronts, in particular over the nature of perception. This book lays the groundwork for Reid's theory of perception by developing Reid's unheralded argument against a representational theory of thought, which this book applies to the discussion of the intentionality of perceptual states and Reid's appeal to ‘signs’. Reid's efforts to preserve common sense epistemic commitments also lead him to adopt unique theories about our concepts of primary and secondary qualities, and about original and acquired perceptions. About the latter pair, the book argues that most perceptual beliefs depend for their justification upon inferences. The Way of Ideas holds that sensations are objects of awareness and that our senses are not robustly unified. This book develops Reid's counter-proposals by examining his discussion of the evolutionary purpose of sensations, and the nature of our awareness of sensations, as well as his intriguing affirmative answer to Molyneux's questions.

Keywords: Way of Ideas, the mind, Thomas Reid, nature of perception, representational theory of thought, intentionality of perceptual states, signs