 Dewey entered the field of psychology while it was dominated by introspectionism (arising from associationism, a.k.a., “mentalism”) and the newer physiological psychology (imported from Germany). Earlier British empiricists, such as John Locke and David Hume, accounted for intelligent behavior with (1) internally inspected (“introspected”) entities, including perceptual experiences (e.g., “impressions”), and (2) thoughts or ideas (e.g., “images”). These accrue toward intelligence by way of an elaborate process of associative learning. Discovery-by-introspection was indispensable for many empiricists, and for many physiological and experimental psychologists (e.g., Wundt) as well.