Full Idea
Perhaps Kripke's argument for the necessity to a thing of its actual origin is that the speculator has to be able to rebut the charge that he has lost his grasp of his subject of discourse if he conceives of this subject with changed parents or origin.
Gist of Idea
If we lose track of origin, how do we show we are maintaining a reference?
Source
report of Saul A. Kripke (Naming and Necessity lectures [1970]) by David Wiggins - Sameness and Substance Renewed 4.10
Book Reference
Wiggins,David: 'Sameness and Substance Renewed' [CUP 2001], p.132
A Reaction
On the whole Wiggins opposes necessity of origin (cf. Forbes, who defends it). If this idea is right, then any means of ensuring reference will do the job, and it clearly wouldn't be an argument that guaranteed necessity of origin.