Full Idea
Locke may have gone a long way towards describing the real essence of a person.
Gist of Idea
Maybe Locke described the real essence of a person
Source
report of John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.27.09) by Robert Pasnau - Metaphysical Themes 1274-1671 30.5
Book Reference
Pasnau,Robert: 'Metaphysical Themes 1274-1671' [OUP 2011], p.725
A Reaction
Locke resisted the idea that we could know real essences, but this idea makes the point that if you give a good definition of something you can hardly fail to be invoking its essence.