‘Are Body and Extension the Same Thing?’ colloquium, September 18
Speech description from Downing
In the course of considering the simple modes of space in book II of the Essay, Locke noted that “there are some that would persuade us, that Body and Extension are the same thing” (2.13.11). Those would be the Cartesians, of course, though Locke, as is typical of him, does not name the sect. Descartes held that extension is the principle attribute or essence of body (corporeal substance) and that in some sense body is nothing more than mere extension, for body is just extension and its modifications. Notoriously, this provides Descartes with a very short argument for the impossibility of a vacuum. Locke is suspicious of both the conclusion and the shortness of the argument. I focus here, however, on his attempts to prove in 2.13.11-14 that body and extension are distinct ideas. My goal is both to evaluate this anti-Cartesian foray, and to use it to reflect on some intriguing and abstruse elements of Descartes’ ontology of body.