Single Idea 14668

[catalogued under 4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / f. System B]

Full Idea

The characteristic of B has the form φ⊃□◊φ. ...Even if these axioms are necessarily true, it seems logically possible for p to be true while the proposition that p is necessarily possible is at the same time false.

Gist of Idea

In B it seems logically possible to have both p true and p is necessarily possibly false

Source

Nathan Salmon (The Logic of What Might Have Been [1989], Intro)

Book Reference

Salmon,Nathan: 'Metaphysics, Mathematics and Meaning' [OUP 2005], p.130


Related Idea

Idea 14667 System B has not been justified as fallacy-free for reasoning on what might have been [Salmon,N]