display all the ideas for this combination of texts
1 idea
8970 | Our notion of identical sets involves identical members, which needs absolute identity [Hawthorne] |
Full Idea: Our conceptual grip on the notion of a set is founded on the axiom of extensionality: a set x is the same as a set y iff x and y have the same members. But this axiom deploys the notion of absolute identity ('same members'). | |
From: John Hawthorne (Identity [2003], 3.1) | |
A reaction: Identity seems to be a primitive, useful and crucial concept, so don't ask what it is. I suspect that numbers can't get off the ground without it (especially, in view of the above, if you define numbers in terms of sets). |