Intensional logic is the technical study of such intensional phenomena in human reasoning as modality, knowledge, or flow of time. These all require a richer semantic picture than standard truth values in one static environment. Such a picture is provided by so-called possible worlds semantics, a paradigm which is surveyed in this book, both as to its external sources of motivation and as to the internal dynamics of the resulting program. In particular, Manual of Intensional Logic presents the major classical topics, including modal logic, tense logic, and conditional logic, all of which illustrate motivations coming from philosophy and linguistics. The Book also discusses recent computational applications in computer science and AI. Finally, Manual of Intensional Logic takes up recent developments in the study of language and information making themselves felt in the area. The Book examines the role of partial information--with illustrations drawn from different branches of Intensional Logic--and various influences stemming from current theories of the semantics of natural language, involving generalized quantifiers and theories of types.
I wonder if David Foster Wallace read this when it came out in 1988, three years after he wrote his paper on the logical philosophy of fatalism? Unfortunately, I seem to recall that van Bentham disposes of the whole "sea battle" argument in about a page and half - with modern tools available, he argues, pretty convincingly, that it's no more than a confusion between predicate logic and modal logic. But I haven't finished reading Wallace's thesis yet, so maybe I'm being too harsh on him. I can see he's using Kripke structures, so perhaps he just reaches the same conclusion in a more long-winded way. I will post an update when I've finished.
Also, to be fair, Wallace was writing an undergraduate thesis, while this is now the standard reference, written by the world's acknowledged leading expert on the subject.