Descartes and Boyle were the most influential proponents of strict mechanist accounts of the physical world, accounts which carried with them a distinction between primary and secondary (or sensible) qualities. For both, the distinction is a piece of natural philosophy. Nevertheless the distinction is quite differently articulated, and, especially, differently grounded in the two thinkers. For Descartes, reasoned reflection reveals to us that bodies must consist in mere extension and its modifications, and that sensible qualities as we conceive of them (...) based on sense perception can pertain only to the mind. Just how we are supposed to arrive at this realization is, this essay will argue, a deep puzzle that brings us to the basic assumptions of Descartes' metaphysics. For Boyle, by contrast, while reflection can reveal the unique explanatory status of mechanism, and, thus, the primary/secondary quality distinction, only experience can confirm its truth. Our central focus will be on Descartes, and on the question: How does he intend to remove the sensible qualities from the physical world, how does he strip them from bodies? I will try to show that Descartes has an argument that he takes to show a priori that sensible qualities cannot be attributed to the material world (as foundational qualities, or, as we conceive of them based on sense experience). The argument fails, however, leaving him with at best a partly empirical case for removing the sensible qualities, based on the purported explanatory success of his physics. (shrink)

ABSTRACTDescartes did not use the terms ‘primary’ and ‘secondary’ qualities, but a similar distinction emerges from his texts: certain qualities of objects are intrinsic pr...

That Descartes’ God is not a deceiver is amongst the canonical claims of early modern philosophy. The significance of this (purported) fact to the coherence of Descartes’ system is likewise canonical, infused in how we teach and think about the _Meditations_. Though prevalent, both ends of this narrative are suspect. We argue that Descartes’ color eliminativism, when coupled with his analysis of the cognitive structure of our sensory systems, entails that God is a deceiver. It’s doubtful that Descartes recognized this, (...) given his insistence that God is not a deceiver, and the role this plays in his system. But this is a concession Descartes can grant if we are careful about the kind of deception at play—a kind Descartes _does_ recognize, albeit not without some ambiguity. On our story, Descartes’ metaphysics and epistemology are not driven by concerns about deception _per se_, but by concerns about God’s _benevolence_. (shrink)