Single Idea 6055

[catalogued under 5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic]

Full Idea

To formulate the law of non-contradiction ('nothing can be both F and non-F') and the law of excluded middle ('everything is either F or it is not-F'), we need the concept of identity (in 'nothing' and 'everything').

Gist of Idea

Both non-contradiction and excluded middle need identity in their formulation

Source

Colin McGinn (Logical Properties [2000], Ch.1)

Book Reference

McGinn,Colin: 'Logical Properties' [OUP 2003], p.11


A Reaction

Two good examples in McGinn's argument that identity is basic to all thinking. But the argument also works to say that necessity is basic (since both laws claim it) and properties are basic. Let's just declare everything 'basic', and we can all go home.