Single Idea 16768

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

Full Idea

If this is, and that is not, then they are not the same entity in being.

Gist of Idea

Two things are different if something is true of one and not of the other

Source

John Duns Scotus (Ordinatio [1302], IV.11.3), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 25.3

Book Reference

Pasnau,Robert: 'Metaphysical Themes 1274-1671' [OUP 2011], p.582


A Reaction

This is the contrapositive of the indiscernibility of identicals, expressed in terms of what is true about a thing, rather than what properties pertain to it.