On Sameness and Identity: A Psychological Study / Being a Contribution to the Foundations of a Theory of Knowledge

The author analyzes the ambiguous concept of sameness, distinguishing several senses in which mental states, perceptions, and objects may be called the same: identity at an instant, repetition of sensations, and the continuity of an object across successive percepts. He examines how perceptual grouping and memory allow isolated experiences to represent whole series, contrasts Idealist and Realist perspectives, and traces logical and epistemological difficulties arising from loose use of the term. The work systematically classifies these senses, illustrates consequences for judgments about objects and self, and advocates precise discrimination to avoid fallacies.