 In our analysis of Hume’s “science of man”, we have already encountered Hume’s claim that we are unable to penetrate into the internal constitution of matter  (section 3).  So, however else Hume’s skepticism is understood—and it has been the subject of intense scholarly discussion (including the so-called “New Hume” debate, see Read &amp; Richman 2000) during the last three decades—the science of man has skeptical implications with regard to his interpretation of Newton’s philosophy. Hume’s evaluation of Newton is an additional source of evidence in understanding the nature of Hume’s skepticism. This evidence reveals that in evaluating Newton’s achievement Hume is pessimistic about the extent and possibility of knowledge of nature. It also shows that Hume rejected important Newtonian standards/criteria in evaluating the claims of natural philosophy.