This book was designed primarily as a textbook; though the author hopes that it will prove to be of interests to others beside logic students. Part I of this book covers the fundamentals of the subject the propositional calculus and the theory of quantification. Part II deals with the traditional formal logic and with the developments which have taken that as their starting-point. Part III deals with modal, three-valued, and extensional systems.

Føllesdal (1966 and 1969) claims that modal distinctions collapse, that is that p and Necessarily p are equivalent, in any system of modal logic that incorporates a standard theory of definite descriptions, like the one proposed by Carnap in M&N. I argue that his argument fails.