Abstract

My topic in this paper will be Hume’s claim that we have no idea of a vacuum. I offer a novel interpretation of Hume’s account of our ideas of extension that makes it clear why those ideas cannot include any ideas of vacuums, and I distinguish my interpretation from prominent readings offered by other Hume scholars. An upshot of Hume’s account, I will argue, is his commitment to a remarkable and distinctly Humean view I call “perceptual relationism.” Perceptual relationism is a fundamental characteristic of Hume’s “universe of the imagination,” and a manifestation of just how “loose and separate” the constituents of that inner universe are. Once we understand perceptual relationism and its entailments, we are in a better position to understand the rest of Hume’s sometimes puzzling remarks on space and the vacuum.