Full Idea
That food nourishes, sleep refreshes, and fire warms us; all this we know, not by discovering any necessary connexion between our ideas, but only by the observation of the settled laws of nature.
Gist of Idea
We discover natural behaviour by observing settled laws of nature, not necessary connections
Source
George Berkeley (The Principles of Human Knowledge [1710], §31)
Book Reference
Berkeley,George: 'The Principles of Human Knowledge etc.', ed/tr. Warnock,G.J. [Fontana 1962], p.79
A Reaction
Hume is famous for this idea, but it is found in Hobbes too (Idea 2364), and is the standard empiricist view of causation. The word 'settled' I take to imply that the laws are contingent, because they could become unsettled at any time.
Related Idea
Idea 2364 Causation is only observation of similar events following each other, with nothing visible in between [Hobbes]