An Enquiry Concerning Human Understanding by David Hume — Summary, Key Ideas & Quotes

Hume argues that all knowledge originates from sensory experience, not from innate ideas or pure reason. He distinguishes between 'relations of ideas' (like mathematics) and 'matters of fact' (knowledge about the world), insisting that only the former can be known with certainty. This leads to a skeptical stance about what reason alone can achieve, especially regarding metaphysics and theology.

One of Hume’s most influential insights is his critique of inductive reasoning—the process by which we infer general laws from particular experiences. He shows that there is no rational justification for assuming that the future will resemble the past, since this assumption itself cannot be proven by reason or experience. This problem still haunts science and philosophy today.