Abstract

According to Robert Sleigh Jr., “The opening remarks of DM.18 make it clear that Leibniz took the results of DM.17 as either establishing, or at least going a long way toward establishing, that force is not identifiable with any mode characterizable terms of size, shape, and motion.” Sleigh finds this puzzling and suggests that other commentators have generally been insufficiently perplexed by the bearing that the DM.17 has on the metaphysical issue. He notes that §17 of the Discourse is a presentation of “the argument of the Brevis demonstratio to the effect that Descartes erred in measuring force in terms of mass and velocity, rather than in terms of mass and the square of velocity,” and observes that, given this, it is initially plausible to think that Leibniz ought to have concluded the very opposite, for “if force were measurable in terms of mass and the square of velocity—then force would be characterizable in terms of size and motion.”