On a standard interpretation, Hume argued that reason is not practical, because its operations are limited to “demonstration” and “probability.” But recent critics claim that by limiting reason’s operations to only these two, his argument begs the question. Despite this, a better argument for motivational skepticism can be found in Hume’s text, one that emphasizes reason’s inability to generate motive force against contrary desires or passions. Nothing can oppose an impulse but a contrary impulse, Hume believed, and reason cannot generate (...) an impulse. This better argument is here developed and defended. Two lines of objection to it can be anticipated: that reason actually can generate impulsive force, based on contents of its normative judgments and that reason neither can nor needs to generate an impulse, since the actions of rational agents are not determined by forceful impulses of desire, as Hume supposed. These objections are answered by pointing out their unsatisfying consequences. (shrink)