Although the problem is perhaps as old as philosophy itself, the concept of ‘personal identity’ is introduced into philosophical discourse by John Locke (1632–1704) in his Essay concerning Human Understanding. For Locke, the issue became pressing because of his agnostic attitude with respect to the existence and essence of substances and therefore with respect to the notion that human persons are, or consist of, substances. It is against this skeptical background that the question as to what constitutes the identity of persons needs to be addressed in Locke, and he does so by turning consciousness and memory into the grounding for, and the criterion of, personal identity.

Spinoza’s concept of mind (mens), including his views about the human mind, is among the most controversial issues of his philosophy; it has prompted many debates, in particular concerning the status of finite minds. That Spinoza might have a problem in this regard was a worry already voiced by Pierre Bayle in his Dictionnaire historique et critique; but the same concern was present in the Pantheism Controversy between Moses Mendelssohn and Friedrich Jacobi, and questions about the status and individuation of the human mind were also driving the readings of Spinoza developed in German Idealism. Critics in particular voiced the concern that Spinozism cannot account for the numerical difference between finite subjects and thus offers no solution to the problem of the individuation of minds.

Imagination (imaginatio, imaginari, imago) is an equivocal term with which Spinoza refers to (1) perceptual states, (2) inadequate ideas, or (3) mental images used in thinking.

Epistemology is in many ways important for Spinoza’s philosophy. It underlies his metaphysics, as well as his ethics and his political theory, and it also connected in many interesting ways with his psychological views on the mental life of human subjects. It is against this background that the present chapter discusses several key concepts and doctrines that Spinoza establishes in his epistemology, such as his views on truth and adequacy, the definition of idea and the denial of the notion of innate ideas, the famous distinction of the three kinds or rather “genera” of knowledge, the cognitive psychology underlying the discussion of the process of the imagination, humanity’s capacity for rationality, and finally the idea of our being blessed by intuitive knowledge. Moreover, regarding Spinoza’s denial of skepticism as the basic motivation driving his epistemology, the chapter also shows how his epistemological views develop over time. Altogether, it is argued that Spinoza manages to establish an epistemology that is both quite consistent on its own terms and successful in providing a stable foundation for his metaphysical, ethical and political views.