Naturalism and the Cartesian ghost

Many philosophers equate naturalism with physicalism. Non-reductive naturalists object that physicalism is inadequate to human agency. Despite their disagreement, both labor under a vestigial Cartesianism that regards the human mind as the sole exception in an otherwise monolithic physical nature. But nonhuman nature is complex, exhibits emergence, and requires multiple sciences. This paper argues that nonhuman nature cannot be adequately understood by physicalism with its doctrine of the causal closure of the physical. At the same time, non-reductive naturalism cannot deny the dependence of human processes on nonhuman nature. A pluralistic naturalism can acknowledge this dependency without accepting physicalism. The Cartesian ghost can only be exorcized by thinking through the complexity of the nonhuman nature that is our home. This permits us to accept the realist, albeit fallibilist, truth of human cognition of the nature that evolved it.