[From Latin adsociare: to join or combine together.]
(epistemology) A theory of knowledge holding that all concepts are formed through the customary or even arbitrary connection of an image or mental idea with an object (based on similarity, closeness in space or time, etc.). The principle of association was first expressed by John Locke (1632-1704) and extended by David Hume (1711-1776). In various forms, associationalism dominated Anglo-American thinking about epistemology for hundreds of years: for instance, it was formalized into a thoroughgoing theory of knowledge in the 19th century (in tandem with sensationalism) and (replacing philosophical "concepts" with psychological "stimulus-response interactions") yielded behaviorism in the 20th century.