Full Idea
If perceptions are distinct existences, they form a whole only by being connected together. But no connexions among distinct existences are ever discoverable. We only feel a connexion ...to pass from one object to another.
Gist of Idea
Perceptions are distinct, so no connection between them can ever be discovered
Source
David Hume (Treatise of Human Nature, + Appendix [1740], Appendix)
Book Reference
Hume,David: 'A Treatise of Human Nature', ed/tr. Selby-Bigge/Nidditch [OUP 1978], p.635
A Reaction
This first part of this is a problem for any 'bundle' theory of objects or self. This is why Hume abandons all hope for his theory of personal identity based on association. You infer the associations, but don't perceive them.