Associationism, also referred to as mental associationism, is a philosophical theory that explains human thought through associations formed in the mind. This theory has garnered several synonyms over time, including associationistic theory, associationist psychology, and mentalism. Other synonyms for associationism include empiricist theory, which posits that all knowledge is acquired through experience, and behaviorism, which emphasizes the role of conditioning in the development of behavior. Furthermore, connectionism, a modern approach to associationism, emphasizes the importance of connections between neurons in the brain. Despite the varying synonyms used to describe this theory, all emphasize the importance of establishing connections between concepts in the mind.