Against the backdrop of fanatical religious conflicts and with an awareness of the exact sciences flourishing in the 17th century, Spinoza developed one of the most ambitious designs in the history of philosophy: his ethics presented in geometric order. It deals with ontology, epistemology, human emotions, and the freedom and unfreedom of individuals as well as social communities in a single continuous line of argument. In this way, the work combines the highest demands for conceptual and justificatory clarity with wisdom saturated by life experience. It sees itself as a guide to happiness for those who are willing to rely solely on their reason and not on authorities. To this day, the book remains a benchmark for enlightened theoretical and practical reason. Its five parts are included in this collection.