For naturalists, philosophy is continuous with the empirical sciences. Scientific research can help answer traditional philosophical questions -- What is knowledge? What makes actions morally right or wrong? What is the relationship between mind and body? What is free will and do we have any? etc. Sometimes, contact with the sciences shapes the philosophical questions themselves.

Contemporary naturalism is rooted primarily in the work of W. V. O. Quine, especially in his attack on the a priori in “Two Dogmas of Empiricism.” Quine there argued against any clear notion of sameness of meaning that can serve as the basis for a priori knowledge. All philosophical beliefs -- even beliefs about the principles of logic -- are warranted to the extent that they fit with our entire web of beliefs, including our best going empirical theories. Theories in different domains are often mutually relevant, Quine recognized, and since Quine, philosophical theories and scientific theories have enjoyed increasing mutual relevance.