"Ethics" is the magnum opus of Spinoza. It contains the foundations, essence, and the majority of his thought: metaphysics, physics, epistemology, anthropology, psychology, ethics (along with elements of religious studies and politics).

The author aims not only to expose but also to prove "in a geometrical manner" the nature and interrelation of things. He strives to highlight the supreme unity of Being by integrating all the separate objects of knowledge into a cohesive and rigorously structured philosophical system.

Nature and God, matter and spirit, extension and thought, the world and humanity, the body and the soul, intertwine in a solid unity. Where Descartes divides, Spinoza unites. His goal is knowledge and truth, but also virtue, freedom, and happiness.