Full Idea
Kant said that the principle of the Identity of Indiscernibles is true only at the level of concepts; two concepts having identical properties are the same concept; the principle is not true at the level of particulars given in sensory experience.
Gist of Idea
The Identity of Indiscernibles is true of concepts with identical properties, but not of particulars
Source
report of Immanuel Kant (Critique of Pure Reason [1781]) by Nicholas Jolley - Leibniz Ch.8
Book Reference
Jolley,Nicholas: 'Leibniz' [Routledge 2005], p.213
A Reaction
Good. I would think that should be the last word on that particular subject. ...Suppose, though, that two people had identical concepts with identical properties, but believed that the extensions (application to particulars) were different?