  With regard to its epistemological implications, what precisely did Locke take the Principia to have achieved?   To pose the question in the starkest possible terms, might Newton’s Principia have tempted Locke to retreat from his belief that natural philosophy cannot be made a science (much as it led him to retreat from the contact action proviso)? Perhaps Locke categorized Newton’s epistemological achievement in natural philosophy as a contribution to sensitive knowledge alone.  That is, perhaps he saw Newton’s “mighty Designs in advancing the Sciences” (Essay, Epistle to the Reader, pp. 9–10) as confined to providing a firm basis for natural philosophy through his experimental method. But did he perhaps instead take Newton’s mathematical methods as offering the demonstrations needed to push natural philosophy into the domain of demonstrative knowledge and hence scientia?