This book provides a completely new and systematic account of Frege's philosophy by focusing on its cornerstone: the theory of sense and reference.Gottlob Frege has exerted an enormous influence on the evolution of 20th century philosophy, yet the real significance of that influence is still very much a matter of debate. This book provides a completely new and systematic account of Frege's philosophy.Gottlob Frege has exerted an enormous influence on the evolution of 20th century philosophy, yet the real significance of that influence is still very much a matter of debate. This book provides a completely new and systematic account of Frege's philosophy.Gottlob Frege has exerted an enormous influence on the evolution of twentieth-century philosophy, yet the real significance of that influence is still very much a matter of debate. This book provides a completely new and systematic account of Frege's philosophy by focusing on its cornerstone: the theory of sense and reference. This study represents a major reassessment of a seminal figure in the history of philosophy, and will be of particular interest to philosophers concerned with language and epistemology.Introduction; 1. Frege's logic; 2. The separation of the psychological from the logical; 3. To break the power of words over the human mind; 4. The thought; a) the objectivity of thought b) sense and thought; 5. The reference of sentences; 6. Judgement and knowledge; 7. The reference and sense of names; 8. Frege's contributions to epistemology; a) Frege's account of empirical knowledge b) the refutation of idealism; Bibliography; Index.