Single Idea 16981

[catalogued under 9. Objects / F. Identity among Objects / 1. Concept of Identity]

Full Idea

It is clear from (x)□(x=x) and Leibniz's Law that identity is an 'internal' relation: (x)(y)(x=y ⊃ □x=y). What pairs (w,y) could be counterexamples? Not pairs of distinct objects, …nor an object and itself.

Gist of Idea

With the necessity of self-identity plus Leibniz's Law, identity has to be an 'internal' relation

Source

Saul A. Kripke (Naming and Necessity preface [1980], p.03)

Book Reference

Kripke,Saul: 'Naming and Necessity' [Blackwell 1980], p.3


A Reaction

I take 'internal' to mean that the necessity of identity is intrinsic to the item(s), and not imposed by some other force.