David Hume, an 18th-century Scottish philosopher, is a towering figure in Western moral philosophy, known for his profound inquiries into human nature, knowledge, and ethics. Coming from the Enlightenment period, Hume lived in a time brimming with ideas that sought to challenge traditional beliefs and explore the foundations of human understanding. He is often remembered for his empirical approach to philosophical questions and his reflections on how these intertwine with morality.

Hume is particularly famous for his exploration of the relationship between reason and passion, which becomes crucial when we examine his moral philosophy. Unlike many of his predecessors, Hume argued that our moral judgments are not primarily the products of rational deliberation but are instead deeply rooted in human emotions. One of his central works, "A Treatise of Human Nature," outlines the idea that our sentiments and feelings play a decisive role in what we value and deem ethical. Hume famously stated that “reason is, and ought only to be the slave of the passions.” This radical claim suggests that our emotional responses are not just significant but foundational in shaping our moral frameworks.

One of the key concepts introduced by Hume is the notion of moral sentiment, which posits that our ethical evaluations come from feelings of approval or disapproval that we experience in response to actions. According to Hume, when we encounter situations, our innate sentiments inform our sense of right and wrong. Hume argues that we, as social creatures, derive a sense of morality from the way our feelings align with those of others. Rather than relying solely on abstract principles or rules, he suggests that morality is rooted in human nature and the common sentiments that we share as members of a community.