Introspection, psychology of

2. The scope of introspection

Does the set of states and processes that can be introspected exhaust the mental? Philosophical responses to this question fall into two traditions. Until well into the nineteenth century, most Anglo-American philosophers, including, in particular, the British Empiricists (Locke, J.,Hume, D., Mill, J.) and the American, William James, followed Descartes in answering in the affirmative (see Empiricism; Sense-data). In contrast, many German philosophers, beginning with Leibniz and including Kant and Schopenhauer, have argued that there are aspects of mind that are hidden from introspective awareness.

The current view is largely anti-Cartesian. Both Freudian psychoanalytic theories and contemporary cognitive science posit the existence of unconscious mental states and processes, that is, mental states and processes to which introspection has no access (see Unconscious mental states). A popular view among psychologists, in fact, is that introspective accessibility is not simply a black and white affair but, rather, that there are multiple levels of consciousness, each with its own conditions of accessibility.