David Hume

Hume's view of morality famously stands in sharp contrast to his contemporary Immanuel Kant. Kant's project was to ground morality in reason: he hoped to reveal an a priori system of universal, natural moral law knowable through analytic reasoning. Hume, on the other hand, felt that morality should be studied empirically as an aspect of human nature; in other words, morality is knowable via synthetic reasoning and justified a posteriori. Hume was therefore a moral naturalist who attempted to understand how humans' feelings and emotional dispositions give rise to moral norms.

Hume argues that the ideas we hold in our minds are copies of sensory impressions, a claim that is generally referred to as the copy principle. In keeping with his broadly empiricist approach, the copy principle serves as a way for Hume to define complex concepts by reducing them to their simple ideas and tracing those ideas back to their sensory impressions. This concept is redeployed in the work of Gilles Deleuze and, through Deleuze, Manuel DeLanda. Deleuze was influenced by Hume's anti-transcendental view of human nature and credits Hume with introducing the notion that relations are external to their terms.