Externalism and Internalism in the Philosophy of Mind
Authors: Wilson Robert A. 
Published: July 2017

Across different areas of philosophy, “internalism” and “externalism” designate distinctly opposed positions. In the philosophy of mind, the debate between internalists and externalists arose in the 1970s with a focus on meaning and mental representation and the nature of mental states. Internalists or individualists hold that the nature of an individual’s mental states depends metaphysically just on facts about that individual, facts intrinsic to that individual, rather than her social or physical environment. A common way to express internalism is to say that an individual’s mental states are fixed or determined by the intrinsic, physical properties of that individual, where this relation of determination has typically been understood in terms of the notion of supervenience. For an individualist, two molecule-for-molecule identical individuals also must have the same mental states. Externalists or anti-individualists deny this. The two seminal papers here—Hilary Putnam’s “The Meaning of ‘Meaning’” (Putnam 1975, cited under Classic and Early Work) and Tyler Burge’s “Individualism and the Mental” (Burge 1979, cited under Classic and Early Work)—both launched attacks on taken-for-granted internalist or individualist views of meaning and mind. They did so in part by introducing thought experiments in which so-called doppelgängers (those molecule-for-molecule identical individuals), located in distinct physical and social environments, had thoughts with different mental contents. In addition, Burge published a large number of papers over the next two decades systematically drawing out the scope and implications of his anti-individualistic views for central topics in the metaphysics and epistemology of mind and cognitive science, including mental causation and psychological explanation, self-knowledge, and computational accounts of cognitive processing. Shifting from the initial focus on meaning and mental content in the 1980s to the idea that cognition is embodied and extends into the environment—the extended mind thesis—the debate over externalism in the philosophy of mind has infused much work on core topics in the field, such as the nature of intentionality, computational psychology, consciousness, perception, experience, functionalism, and materialism. The sections General Background, Classic and Early Work, Philosophy of Language/Mind Interface, and the Extended Mind and Cognition below provide background and fundamental readings on internalism and externalism in the philosophy of mind. Sections from Mental Causation and Explanation I to Knowledge and Self-Knowledge give coverage to particular topics, such as intentionality and consciousness. Sections Other Cognitive Science and Philosophy of Science: Articles and Other Cognitive Science and Philosophy of Science: Books cover miscellaneous books and articles that focus primarily on cognitive science and the philosophy of science. Some sectional divisions are artifacts of the ten entries-per-section constraint, together with finding no more meaningful way to categorize these entries. Other Oxford Bibliographies articles with complementary content include “Epistemology and Active Externalism,” “The Extended Mind Thesis,” “Self-Knowledge,” and “Supervenience.”