Abstract

Many philosophres have attempted to argue from the "Humean Theory of Motivation" (HTM) and the "Internalism Requirement" (IR) to the "Humean Theory of Practical Reason" (HTPR). This argument is familiar, but it has rarely been stated with sufficient precision. In this paper, I shall give a precise statement of this argument. I shall then rely on this statement to show two things. First, the HTPR is false: it is incompatible with some extremely plausible assumptions about weakness of will or akrasia. Second, this argument for the HTPR is invalid: even if the HTM and the IR are true, they do not provide any support whatsoever to the HTPR.