Full Idea
As a general law of substitutivity of identicals, Leibniz's Law is false. It is a law about properties and relations, that if two things are identical, they have the same properties and relations. It only works in contexts which attribute those.
Gist of Idea
Leibniz's Law isn't just about substitutivity, because it must involve properties and relations
Source
Allan Gibbard (Contingent Identity [1975], V)
Book Reference
-: 'Journal of Symbolic Logic' [-], p.201
A Reaction
I'm not convinced about relations, which are not intrinsic properties. Under different descriptions, the relations to human minds might differ.
Related Idea
Idea 8650 Things are the same if one can be substituted for the other without loss of truth [Leibniz]