  The laws of motion held a privileged place in the mechanical  philosophy of the early modern period. Together with bodies they  served as the chief explanatory postulates of the new physics. It is  thus not surprising that Leibniz held strong views concerning the  justification of the laws of motion, the content of those laws, and  their implications for the epistemology and metaphysics of motion. In thinking about Leibniz’s positive views on the laws of motion, it  might prove once again helpful to first look at his reasons for being dissatisfied with the account offered by Descartes. 