An Enquiry Concerning Human Understanding
1748 · David Hume
Core ideas
- All ideas ultimately derive from sensory impressions.
- We observe constant conjunction, never necessary causal connection.
- Belief in cause and effect rests on custom and habit, not reason.
- Induction cannot be rationally justified without circularity.
Summary
Hume argues that all the contents of the mind derive from experience: vivid impressions and the fainter ideas copied from them. Any idea that cannot be traced to an impression is suspect. Applying this test, he turns to causation and finds that we never actually perceive a necessary connection between cause and effect — only one event regularly following another.
Our confidence that the future will resemble the past, he shows, rests not on reason or proof but on habit. This is the problem of induction. The Enquiry extends the same skeptical scrutiny to miracles and to the limits of human knowledge, modeling a temperate, fallibilist way of holding beliefs.