G. H. Mead developed an alternative "metaphysics" of selfhood and agency that underlies, but is seldom made explicit in discussions of, his social developmental psychology. This is an alternative metaphysics that rejects any pregiven, fixed foundations for being and knowing. It assumes the emergence of social psychological phenomena such as mind, self, and deliberative agency through the activity of human actors and interactors within their biophysical and sociocultural world. Of central importance to the emergence of self-consciousness and deliberative forms of (...) human agency is the ability of developing individuals to take the perspectives of others within their own conduct. However, precisely what is involved in this process, and whether or not it assumes the preexistence of exactly those forms of selfhood and agency, the emergence of which it seeks to explain, have been much disputed. In this essay, recent reinterpretations of Mead's "metaphysics" are used to argue that his overall theoretical program contains resources necessary to overcome charges of ontological and epistemological circularity. In particular, once his interactionism, perspectivism, emergentism, and compatibilism are explicated, it is possible to see that Mead's "taking the perspective of the other" is not primarily a process of internalization that requires a preexisting "internalizer," but a process of participation with others within conventionalized sequences of interactivity. This participatory process enables the development of prereflective forms of perspective taking and self-other differentiation that serve as necessary conditions for the further emergence of more reflective forms of perspective taking, self-consciousness, and deliberative agency. Compatibilist interpretations of deliberative agency, thus understood, also are discussed. (shrink)