This book treats modal logic as a theory, with several subtheories, such as completeness theory, correspondence theory, duality theory and transfer theory and is intended as a course in modal logic for students who have had prior contact with modal logic and who wish to study it more deeply. It presupposes training in mathematical or logic. Very little specific knowledge is presupposed, most results which are needed are proved in this book. Chapter Headings only. About this Book. Overview. Part 1. The Fundamentals. Algebra, logic and deduction. Fundamentals of modal logic I. Fundamentals of modal logic II. Part 2. The General Theory of Modal Logic. Universal algebra and duality theory. Definability and correspondence. Reducing polymodal logic to monomodal logic. Lattices of modal logics. Part 3. Case Studies. Extensions of K4. Logics of bounded alternativity. Dynamic logic. Index. Bibliography. ....As a whole, the book deserves attention from specialists in the field....The author has succeeded in showing that the use of mathematical (algebraic and topological) tools provides an excellent means for deeper understanding of the theory. Bulletin of the Symbolic Logic