 While Cartesian epistemology offers an especially vivid instance of all of the features of TE discussed above, some of those same tendencies and concerns are, of course, present in varying degrees in the work of other figures in the epistemological canon. The assumption that epistemology trades in normative matters, and not just description  (c),  and an abiding concern with skepticism  (d),  for example, can be seen in much epistemology from Descartes through to the present.