Intentionality in the works of Martin Heidegger and Wilfrid Sellars

I examine how intentionality is addressed by the early Heidegger and by Sellars. They are best understood as providing a critique of Cartesian dualism. Heidegger contends that traditional dualism underestimates the difference between the 'manner of existence' belonging to human beings and that belonging to mere things. Sellars' strategy is to reconcile our concept 'mind' with the concepts belonging to the natural sciences.;Heidegger argues that intentionality, whether in terms of practice or thought, is based on the peculiar manner in which humans exist, which in his terms is called 'being-in-the-world'. 'Being-in-the-world' includes the capacity to exist as a self, and selfhood can be explicated only by the peculiar way in which selfhood is related to temporality. Heidegger concludes that the being of things is merely to exist in time, whereas to exist as a self is to exist 'as' time. This radical difference is the basis for his critique of Descartes' substance dualism.;Sellars argues that the intentionality of thought is simply a concept derivative of the semantical discourse which speakers of a language use to capture the proper functioning of terms in their language. Sellars claims the concept 'thought' is a theoretical concept, and he develops a complex account of how 'thought' is, in its primary sense, a concept used to explain the overt behavior of other humans and, in its secondary sense, a concept modified for the use of explaining one's own behavior. Sellars concludes that, since (a) the concept 'thought' is primarily a theoretical concept and (b) the concept 'intentionality' is a functional concept pertaining to the semantical discourse of language-users, nothing remains as an obstacle to viewing 'thoughts' as neurophysiological processes in the brain.;I argue that Heidegger's analysis of selfhood presents a difficulty for the Sellarsian project to reconcile intentionality with the discourse of the natural sciences. Sellars, however, claims that the concept 'person' cannot be reconciled with the discourse of the natural sciences, but rather must be added to it. I contend that Sellars' reasons for rejecting the 'naturalization' of 'person' should apply equally to his attempt to naturalize the concept 'intentionality'.