Experience, causation, and induction › Why tomorrow is a further question

Your train has arrived on time every morning this month. You leave home expecting the same service tomorrow. Asked for a reason, you point to its record. Asked why that record tells you what will happen next, you might say that a service which has been reliable will probably remain reliable. That is a useful everyday answer. It also repeats the step that needs explaining: the move from cases already observed to a case you have not observed.

This invented example introduces the question at the center of David Hume's Enquiry concerning Human Understanding. What allows experience to inform expectations about something beyond experience? Hume is interested in the ordinary confidence that makes planning possible. His challenge becomes difficult precisely because the inference feels so familiar. The train's past arrivals are evidence about its past. Tomorrow's arrival is a further claim.

The work was first published in 1748. The primary text linked throughout this chapter follows Hume's later, 1777 text, with section and paragraph references such as E 4.16. Its central discussion moves from the origin of ideas to causal inference, then from skeptical doubts to an account of how belief actually operates. That order matters. Hume asks both whether an inference has an argumentative foundation and what moves a human being to make it. Those questions can have different answers. Primary text and editions.