On James's argument against epiphenomenalism

Epiphenomenalism is the doctrine that mental states lack causal efficacy. A common objection against epiphenomenalism is that this makes it mysterious how or why mental states ever evolved. One particularly powerful form of this objection was developed by William James. James argued that epiphenomenalism cannot account for the familiar fact that what we find pleasurable is typically good for us, while what we find painful is typically bad for us. In this paper it is argued that James’s objection to epiphenomenalism is sound. But it is further argued that James’s argument constitutes a difficulty, not just for epiphenomenalism, but also for the thesis that mental states do possess causal powers. The paper concludes with some suggestions about how the problem to which James has drawn our attention might be solved.