  In classical first-order logic intension plays no role. It is extensional by design since primarily it evolved to model the reasoning needed in mathematics. Formalizing aspects of natural language or everyday reasoning needs something richer. Formal systems in which intensional features can be represented are generally referred to as intensional logics. This article discusses something of the history and evolution of intensional logics. The aim is to find logics that can formally represent the issues sketched above. This is not simple and probably no proposed logic has been entirely successful. A relatively simple intensional logic that can be used to illustrate several major points will be discussed in some detail, difficulties will be pointed out, and pointers to other, more complex, approaches will be given.