In this article, I address two objections developed by Kingma against Boorse’s (1977) bio-statistical theory of health, the objections that choice of reference classes renders the theory both circular and problematically value-laden. These objections not only apply to the bio-statistical theory of health but also to other naturalistic theories, like the dispositional theory of health. I present three rejoinders. First, I argue that the circularity objection arises from excessive methodological demands. Second, I argue that naturalists can resist the normativist claim that health and pathology are differentiated on the basis of personal or cultural values. Finally, I show that it is possible to justify choices between rival theories of healt...