Abstract
This encyclopedic text analyzes, in a systematic way, the origins of intensional logic and the characteristic differences between the extensional and intensional approach to logic. It discusses the reasons that have led to the formation of modal and consequently intensional logic and analyzes two variants of intensional logic: the 'global' one, exemplified by the system of R.
Montague, and the 'local' one, represented by the transparent intensional logic of P. Tichý.
It scrutinizes the differences between the two kinds of systems in detail. It discusses also the limitations of intensional logic, which can lead to the development of various versions of 'hyperintensional' logics.