Full Idea
The heart of Locke's account of personal identity is the claim that identity of substance is irrelevant.
Gist of Idea
Locke sees underlying substance as irrelevant to personal identity
Source
report of John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.27.25) by Harold Noonan - Personal Identity 2.6
Book Reference
'Personal Identity', ed/tr. Perry,John [University of California 1975], p.49
A Reaction
It is irrelevant whether a sound recording is made of wax, vinyl or CD-stuff. This is a functionalist view. A basic question is whether we consider it naturally or metaphysically possible to make a person out of anything other than brain.