Full Idea
It makes a great difference to ask concerning Socrates whether he is the same human being or whether he is the same body. For his body, when he is old, cannot be the same it was when he was an infant. …He can, however, be the same human being.
Gist of Idea
As an infant, Socrates was not the same body, but he was the same human being
Source
Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.11.07)
Book Reference
Hobbes,Thomas: 'Metaphysical Writings', ed/tr. Calkins,Mary Whiton [Open Court 1905], p.85
A Reaction
This is not commitment to full (Geachian) relative identity, but it notes the problem.