ABSTRACT There is a growing interest in various forms of naturalism in bioethics, but there is a clear need for further clarification. In an effort to address this situation, I present three epistemological stances: anti‐naturalism, strong naturalism, and moderate pragmatic naturalism. I argue that the dominant paradigm within philosophical ethics has been a form of anti‐naturalism mainly supported by a strong ‘is’ and ‘ought’ distinction. This fundamental epistemological commitment has contributed to the estrangement of academic philosophical ethics from major social (...) problems and explains partially why, in the early 1980s, ‘medicine saved the life of ethics’. Rejection of anti‐naturalism, however, is often associated with strong forms of naturalism that commit the naturalistic fallacy and threaten to reduce the normative dimensions of ethics to biological imperatives. This move is rightly dismissed as a pitfall since ethics is, in part, a struggle against the course of nature. Rejection of naturalism has drawbacks, however, such as detering bioethicists from acknowledging the implicit naturalistic epistemological commitments of bioethics. I argue that a moderate pragmatic form of naturalism represents an epistemological position that best embraces the tension of anti‐naturalism and strong naturalism: bioethics is neither disconnected from empirical knowledge nor subjugated to it. The discussion is based upon historical writings in philosophy and bioethics. (shrink)