Nietzsche and Hume agree that desire drives all human action and practical reasoning. This shared view helps them appreciate continuities between human and animal motivation and sets them against a long tradition of rationalist rivals including Kant and Plato. In responding to Kant, Nietzsche further developed the Humean views that Kant himself was responding to. Kantians like Christine Korsgaard argue that reflective endorsement and rejection of options presented by desire demonstrates reason’s ability to independently drive reasoning and action. In Daybreak 109, Nietzsche provides a simpler Humean explanation: reflective endorsement and rejection involve reflecting on one desire from the viewpoint of another, with desire as the only motiv...