Intellectualism is the widespread view that practical reason is a species of theoretical reason, distinguished from others by its objects: reasons to act. I argue that if practical reason is a species of theoretical reason, practical judgments by nature have nothing to do with action. If they have nothing to do with action, I cannot act from my representation of reasons for me to act. If I cannot act from those representations, those reasons cannot exist. If they cannot exist, neither (...) can a species of theoretical reason about them. Intellectualism is thus self-undermining. (shrink)