This is a reply to Donald Ainslie's discussion of Terence Penelhum's work on Hume, Locke and the nature of consciousness; although agree on many points about the differences between Locke and Hume, I take issue with Ainslie's views about the epistemic status Hume accords to introspective acts.

Ted Sider aptly and concisely states the self-visitation paradox thus: 'Suppose I travel back in time and stand in a room with my sitting 10-year-old self. I seem to be both sitting and standing, but how can that be?' (2001, 101). I will explore a relativist resolution of this paradox offered by, or on behalf of, endurantists.1 It maintains that the sitting and the standing are relative to the personal time or proper time of the time traveler and is intended (...) to yield the result that Ted is sitting at a certain initial personal/proper time but is not standing relative to that time. Similarly, it is also supposed to yield that Ted is standing relative to a later personal/proper time, but not sitting relative to that .. (shrink)

Where Terence Penelhum sees a deep continuity between John Locke's theory of ideas and David Hume's theory of perceptions, I argue that the two philosophers disagree over some fundamental issues in the philosophy of mind. While Locke treats ideas as imagistic objects that we recognize as such by a special kind of inner consciousness, Hume thinks that we do not normally recognize the imagistic content of our perceptions, and instead unselfconsciously take ourselves to sense a shared public world. My disagreement (...) with Penelhum over Hume's debt to Locke helps to explain our disagreement over the nature of Hume's scepticism. (shrink)