Hume on Identity and Imperfect Identity

In §6 of Book 1, Part 4 of the Treatise, Hume appears to be inconsistent in his comments about ascriptions of identity to series of successive, significantly related items or to purported single things whose temporal stages are qualitatively different or temporally discontinuous. For example, in the first few pages of §6, Hume explicitly labels such ascriptions “mistakes” and “confusions” (THN, 1. 4. §6, 253–254). Later on in the same section, however, he deals with the alleged identity-preservation of minds, churches, rivers, and so forth and no longer remarks that these attributions of identity are confused or mistaken. Hume claims that the idea of identity is the idea of an item which is (1) invariable, i.e., serially uniform, and (2) uninterrupted, i.e., temporally continuous, which seems to last through time (THN, 1. 4. §2, 200–201; 1. 4. §6, 253). Thus, on page 255 he states that “identity” is used “in an improper sense” if attributed to a series of related items which are either different in kind or temporally discontinuous, viz., to a purported identity-preserving thing whose temporal stages are different in kind or temporally discontinuous. Yet, on page 258, he comments that calling a church which has been rebuilt of different materials and in a different architectural style the same church as the former one can be done “without breach of the propriety of language”. Presumably, this use of “same” is a proper sense of “same”.