Abstract: This chapter defends a radically naturalistic metaphysics, which is motivated exclusively by attempts to unify hypotheses and theories that are taken seriously by contemporary science. For reasons to be explained, this chapter takes the view that no alternative kind of metaphysics can be regarded as a legitimate part of our collective attempt to model the structure of objective reality. One of the most distinguished predecessors in this attitude is Wilfrid Sellars, who expressed a naturalistic conception of soundly motivated metaphysics when he said that the philosopher's aim should be “knowing one's way around with respect to the subject matters of all the special [scientific] disciplines” and “building bridges” between them. This chapter focuses on a sense of “understanding” that is perhaps better characterized by the word “explanation”, where an explanation must be true (at least in its most general claims). It is argued that a given metaphysic's achievement of domestication furnishes no evidence at all that the metaphysic in question is true, and thus no reason for believing that it explains anything.

Keywords: scientism, metaphysics, intuitions, common sense, verificationism, Wilfrid Sellars, science, reductionism, principle of naturalistic closure,