ABSTRACT
The new seventeenth-century science of physics - that is, knowledge of the physical or nature - was the science of bodies in motion. For in the new doctrine, as we have seen, the physical was identified with the corporeal. Descartes' theory, which identified the primary physical existent not with bodies but with the mathematical res extensa, was thus in significant inconsistency with this modern conception of the science of physics. Strictly for Descartes the science of the physical was the science of res extensa, and this science was pure mathematics. 1 The science of bodies in motion was for Descartes accordingly the science of physics only in a derivative sense. Descartes however did not press this implication of his position, namely that the science of physics as it was being developed in his time was concerned with entities of a derivative and subordinate status. Rather he tended to blur this implication by his frequent ambiguity in regard to the status of bodies, often writing of them as if identical with res extensa.
