 Though these are the most prominent uses of the intrinsic/extrinsic distinction in philosophy, they by no means exhaust its uses. Many applications of the distinction are cited by I. L. Humberstone (1996), including the following: George Schlesinger (1990) uses the distinction between intrinsic and extrinsic properties to state a non-trivial version of Mill’s principle of the uniformity of nature. Wlodzimierz Rabinowicz (1979) uses the distinction to formulate principles of universalizability for moral principles and natural laws. And E. J. Khamara (1988) uses a distinction between relational and non-relational properties to state a non-trivial version of the principle of Identity of Indiscernibles.