Full Idea
A change in any considerable part of a body destroys its identity; but 'tis remarkable that where the change is produced gradually and insensibly we are less apt to ascribe to it the same effect.
Gist of Idea
A change more obviously destroys an identity if it is quick and observed
Source
David Hume (Treatise of Human Nature [1739], I.IV.6)
Book Reference
Hume,David: 'A Treatise of Human Nature', ed/tr. Selby-Bigge/Nidditch [OUP 1978], p.256
A Reaction
Broad spotted that landscapes change too, but so slowly that we barely admit any change at all. The type of change also matters. If my car slowly changes to chocolate the speed of change is a minor factor.