Does a sound mind require a sound body? Whether or not lay people subscribe to this notion depends on their belief in mind-body dualism and critically shapes their health-related behaviors. Six studies (N = 1,710) revisit the relation between dualism and health. We replicate the negative correlation between belief in dualism and health behavior (Study 1) and extend it to behavior in the field (Study 2). Studies 3a and 3b investigate how belief in dualism shapes intuitions about the material origin of psychological well-being, while Studies 4a and 4b examine how these intuitions determine health-related outcomes. In sum, construing minds as different from bodies entails the intuition that mental well-being has little material substrate which in turn attenuates health-sustaining behaviors.