ABSTRACT
The following three metaphysical doctrines can be traced back to David Hume: 1 (i) Things persist through change (to the extent that they do) in virtue of having different temporal parts at different times; (ii) a series of temporal parts constitutes a persisting thing only if later temporal parts are causally dependent upon earlier ones in appropriate ways; (iii) causation is not a fundamental relation between events, but something that supervenes upon more humdrum properties and relations. In Hume, these theses are mixed up with an element of scepticism that is, by and large, rejected by his modern-day legatees. Whereas Hume is inclined to dismiss ‘[a]ll disputes concerning the identity of connected objects’ (i.e., successions of temporal parts) as ‘merely verbal, except so far as the relation of parts gives rise to some fiction or imaginary principle of union’; contemporary Humeans treat the persistence of objects as an objective phenomenon, arising from principles of union that are not dependent upon arbitrary decisions to use language in one way or another. Some series of temporal parts really are causally connected, and others are not. At least some of the former have sums that are persisting objects belonging to the natural kinds that interest biologists, chemists, and physicists; the latter may or may not have sums, but at any rate they do not constitute persisting things belonging to natural kinds.
