A.M. Polyakov, one of the world's foremost leaders on the subject of field theory, has created a book from his own scientific diary, synthesizing the most promising approaches and ideals in field theory today. Polyakov presents such subjects as statistical mechanics, quantum field theory and their interrelation, continuous global symmetry, non-Abelian gauge fields, instantons and the quantum theory of loops, and quantum strings and random surfaces. This book is ideally suited for postgraduate students studying field theory and statistical mechanics and for research workers in continuous global theory.