Full Idea
The bundle theory of substance requires unconditional commitment to the truth of the Principle of the Identity of Indiscernibles: that things that are alike with respect to all of their properties are identical.
Gist of Idea
The bundle theory of substance implies the identity of indiscernibles
Source
Cynthia Macdonald (Varieties of Things [2005], Ch.3)
Book Reference
Macdonald,Cynthia: 'Varieties of Things' [Blackwell 2005], p.82
A Reaction
Since the identity of indiscernibles is very dubious (see Ideas 1365, 4476, 5746, 7928), this is bad news for the bundle theory. I suspect that all of these problems arise because no one seems to have a clear concept of a property.
Related Ideas
Idea 4476 Most philosophers think that the identity of indiscernibles is false [Moreland]
Idea 5746 The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia]
Idea 7928 The Identity of Indiscernibles is false, because it is not necessarily true [Macdonald,C]