Berkeley: Primary and Secondary Qualities

This chapter revisits three key disagreements between Locke and Berkeley. The disagreements relate to abstraction, the idea of substance, and the status of the primary/secondary quality distinction. The goal of the chapter is to show that these disagreements are rooted in a more fundamental disagreement over the nature of ideas. For Berkeley, ideas are tied very closely to perceptual content. Locke adopts a less restrictive account of the nature of ideas. On his view, ideas are responsible for both perceptual content (...) and non-perceptual mental content. Recognizing this allows for the following analysis of their disputes. Berkeley often appeals to introspection to suggest that we do not have some particular idea. But Locke’s arguments that we have a particular idea often appeal to the functional role the idea has in our cognitive economy rather than to facts about our immediate phenomenology. (shrink)

Commentators have rightly focused on the reasons why Hume maintains that the conclusions of skeptical arguments cannot be believed, as well as on the role these arguments play in Hume’s justification of his account of the mind. Nevertheless, Hume’s interpreters should take more seriously the question of whether Hume holds that these arguments are demonstrations. Only if the arguments are demonstrations do they have the requisite status to prove Hume’s point—and justify his confidence—about the nature of the mind’s belief-generating faculties. (...) In this paper, I treat Hume’s argument against the primary/secondary quality distinction as my case study, and I argue that it is intended by Hume to be a demonstration of a special variety. (shrink)

I propose a reading of Berkeley's Essay towards a New Theory of Vision in which Molyneux-type questions are interpreted as thought experiments instead of arguments. First, I present the general argumentative strategy in the NTV, and provide grounds for the traditional reading. Second, I consider some roles of thought experiments, and classify Molyneux-type questions in the NTV as constructive conjectural thought experiments. Third, I argue that (i) there is no distinction between Weak and Strong Heterogeneity theses in the NTV; (ii) (...) that Strong Heterogeneity is the basis of Berkeley's theory; and (iii) that Molyneux-type questions act as illustrations of Strong Heterogeneity. (shrink)