De la Figure, & de la Porosité de Corps

Just added to our online edition of the Paris Manuscript of Du Châtelet’s Institutions de Physique is the ninth manuscript chapter, which focuses on the density and porosity of bodies. You can read the transcriptions of the chapter and a full introduction here.

An excerpt from the introduction by Hanns-Peter Neumann and Aaron Wells, on significant changes in the revisions of the manuscript:

One important stage in the revision process is a passage at fol. 165v that only appears in variants C and D, as it is later cancelled. In this passage, Du Châtelet lays out a thought experiment: someone who only had the sense of sight, but not the sense of touch, would in her view be unable to grasp the idea of the impenetrability of bodies. This is supposed to reinforce her claim that we know of impenetrability through touch. There are parallels here to the celebrated ‘Molyneux Problem,’ posed by William Molyneux in a letter to Locke. The puzzle is whether someone born blind, but able to distinguish the shapes of solid objects by touch, would be able to distinguish them by sight if he became able to see. A later version of this discussion from version E, at fol. 165r, retains the emphasis on touch, but associates it with “solidity” rather than “resistance,” and no longer includes the thought experiment.