This chapter examines varieties of naturalism in philosophy of mind and science. Naturalism holds that mental phenomena fit within the natural world as understood by the natural sciences. It takes normative and positive forms, can be a metaphysical or explanatory claim, and is based on reductive, nomic, or evolutionary paradigms for explanation. The preeminent importance of reductive naturalism in philosophy of mind is explained.
In contemporary philosophy of mind, several positions address whether the mind can be explained by natural science. Reductionists argue the mind is reducible to natural phenomena, while eliminativists hold that if it cannot be reduced, mentalistic concepts should be replaced with naturalistic ones. Dualists point to an explanatory gap between mind and nature, concluding the mind is not reducible and that either substance or property dualism follows. Mysterians agree the mind is irreducible but attribute this to human cognitive limitations. Nonreductive materialists reject reduction yet maintain the mind is nothing beyond natural phenomena. All these views share the assumption that intertheoretic reduction is the norm in natural sciences, which drives both reductionism and the perception of the explanatory gap as uniquely problematic.