The "Ethics" is Spinoza's main work, which he worked on from 1662 to 1675. It encompasses the entirety of his philosophy, which he - unlike any other major philosopher - has summarized in a single work. The work is divided into five parts, with the first part presenting a theory of the fundamental structures of the world, the second part a theory of human knowledge, and the remaining three parts an ethics of rational human action, which - as the title "Ethics" indicates - is the culmination of his entire philosophy.