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Single Idea 4942

[filed under theme 9. Objects / F. Identity among Objects / 8. Leibniz's Law ]

Full Idea

It seems to me that the Leibnizian principle of the indiscernibility of identicals (not to be confused with the identity of indiscernibles) is as self-evident as the law of contradiction.

Gist of Idea

The indiscernibility of identicals is as self-evident as the law of contradiction

Source

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

Book Ref

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


A Reaction

This seems obviously correct, as it says no more than that a thing has whatever properties it has. If a difference is discerned, either you have made a mistake, or it isn't identical.


The 8 ideas from 'Naming and Necessity preface'

With the necessity of self-identity plus Leibniz's Law, identity has to be an 'internal' relation [Kripke]
The indiscernibility of identicals is as self-evident as the law of contradiction [Kripke]
A man has two names if the historical chains are different - even if they are the same! [Kripke]
The very act of designating of an object with properties gives knowledge of a contingent truth [Kripke]
Instead of talking about possible worlds, we can always say "It is possible that.." [Kripke]
Probability with dice uses possible worlds, abstractions which fictionally simplify things [Kripke]
Possible worlds allowed the application of set-theoretic models to modal logic [Kripke]
I don't think possible worlds reductively reveal the natures of modal operators etc. [Kripke]