Full Idea
To use Kripke's semantics, one needs extensive intuitions that certain properties are essential and others accidental.
Gist of Idea
Kripke's semantics needs lots of intuitions about which properties are essential
Source
Allan Gibbard (Contingent Identity [1975], X)
Book Reference
-: 'Journal of Symbolic Logic' [-], p.212
A Reaction
As usual, we could substitute the word 'necessary' for 'essential' without changing his meaning. If we are always referring to 'our' Hubert Humphrey is speculations about him, then nearly all of his properties will be necessary ones.