De Dijn's comprehensive introduction to Spinoza's philosophy is based on two key texts. He first provides an in-depth analysis of Spinoza's Treatise on the Improvement of the Understanding, which De Dijn characterizes as his introduction to philosophy. This notoriously difficult text is here made accessible, even in its details. This analysis is followed by a comprehensive survey of Spinoza's metaphysics as presented in his famous Ethics. De Dijn demonstrates how Spinoza's central philosophical project as introduced in the Treatise-the linkage of knowledge and salvation-is perfectly realized in the Ethics. In this way the unity of Spinoza's thought is shown to consist in his preoccupation with the "ethical" question of salvation. The book also contains introductory chapters on Spinoza's life and work, the original Latin text of the Treatise and its new English translation by Edwin Curley, and an annotated bibliography on the secondary literature.