 Thus, for example, it seems plausible that a ball’s sphericality is grounded in spatiotemporal relations among its parts (as Leibniz argued; Leibniz to De Volder April 1702 [G II, 240; 1969: 526–527]; see  section 2.1  below) and is therefore merely relatively intrinsic. A similar point applies to other intrinsic properties described in physics. For example, although mass would seem to be an intrinsic property of material entities, in the passage quoted above Chalmers remarks that in physical theory, “all that a specification of mass ultimately comes to is a propensity to be accelerated by certain forces, and so on” (Chalmers 1996: 153). Accordingly, the only aspects of mass that physical theory describes are relatively, not absolutely, intrinsic.