John, List:
JFS: The first is that all modern versions of modal logic after C. I. Lewis
(including those based on post-1970 methods) are consistent with or
variations of one or more of the versions specified by Lewis.
Indeed, Lewis specified *S1*-*S5* in 1932, of which only *S4* and *S5* are
nor
Jon, List,
I don't have time to respond right now. But there are two points that are
true for every version of modal logic from Aristotle to the Scholastics to
Peirce and to the latest and greatest versions of today:
1. For every version of modal logic, there is some reason WHY certain worlds
