Full Idea
Total ways things cannot be are also 'worlds', or maximal ways for things to be. They are impossible worlds.
Gist of Idea
Impossible worlds are also ways for things to be
Source
Nathan Salmon (The Logic of What Might Have Been [1989], I)
Book Reference
Salmon,Nathan: 'Metaphysics, Mathematics and Meaning' [OUP 2005], p.132
A Reaction
This unorthodox view doesn't sound too plausible to me. To think of a circular square as a 'way things could be' sounds pretty empty, and mere playing with words. The number 7 could be the Emperor of China?