 (Reductive) representationalists (Dretske, Lycan, Tye) usually take one or another of these theories to provide an explanation of the (non-conceptual) content of experiential states. They thus tend to be externalists (see the next section) about phenomenological as well as conceptual content. Phenomenalists and non-reductive representationalists (Block, Chalmers, Loar, Peacocke, Siewert), on the other hand, take it that the representational content of such states is (at least in part) determined by their intrinsic phenomenal properties. Further, those who advocate a phenomenally-based approach to conceptual content (Horgan and Tienson, Kriegel, Loar, Pitt, Searle, Siewert) also seem to be committed to internalist individuation of the content (if not the reference) of such states.