 A good deal of resemblance to Locke’s epistemological approach can be seen in Newton, who holds that, revelation apart, we must gather what knowledge we can from our perceptions, and anything like a real essence eludes us.  In the early manuscript, De Gravitatione, for instance, Newton denies knowing the “essential and metaphysical constitution” of matter (Newton, 2004, p. 27). He reiterates this position in later texts, including the 1713 General Scholium: “We certainly do not know what is the substance of any thing. We see only the shapes and colors of bodies, we hear only their sounds, we touch only their external surfaces….But there is no direct sense and there are no indirect reflected actions by which we know innermost substances”(Principia, 942).