This article explores the possibility of naturalized theory of action. It distinguishes ontological naturalism from conceptual naturalism, and asks whether a defensible theory of action can be either ontologically or conceptually naturalistic. The distinction between conditions for an ontology and conditions for a concept receives support from Donald Davidson's identification of two modes of explanation for action: rational and physical causal explanation. Davidson's action theory provides a naturalized ontology for action theory, but not a naturalized concept of intentional action. This (...) article raises doubts about Davidson's basis for such one-sided naturalism. It examines some conditions for a mode of explanation, in order to clarify whether an intentional mode of explanation might have ontological significance and thus raise problems for ontological naturalism. The article argues for the central role of certain instrumental factors in explanatory strategies, whether naturalistic or intentional; and it casts doubt on Jaegwon Kim's recent argument that intentional psychology and neuroscience are mutually exclusive as explanatory strategies. A key lesson is that variable end-dependent reasons are our only wherewithal in the evaluation of explanatory strategies. In this sense, our explanatory strategies are ultimately instrumental and perspectival. The article draws out the implications of this lesson for naturalized action theory and for psychological explanation. It opposes any suggested monopoly on explanation from the physical sciences. (shrink)