ABSTRACT
Naturalism in philosophy demands that philosophical proposals exhibit a healthy respect for the methods and findings of the empirical sciences, especially when those proposals address the same domains those sciences do. In the twentieth century, philosophers became a good deal more circumspect about their physical and biological speculations. If philosophy of science has not largely overshadowed metaphysics, then certainly science itself has become a fundamental constraint on credible metaphysical proposals. Instead of advancing grand metaphysical programs, many twentieth century philosophers have chosen to explore the broader implications of prevailing scientific theories and attempted to disentangle apparent conceptual snarls some seem to contain.
