The concept of Methodenstreits is used to analyse the relationship between behavioral and mainstream economics. A Methodenstreit is understood by the authors as a dispute between the more abstract and the less abstract canons of the economic science. It undergoes several necessary stages: discovery of a new research instrument, an exaggerated debate between the canons, and mutual enrichement after the debate. The article reviews the following Methodenstreits: empirical investigations of Hall, Hitch, and Lester vs neoclassical theory of the firm (the ‘full cost controversy’ and the ‘marginalist controversy’); Katona’s consumer research vs Keynesian macroeconomics; Simon’s bounded rationality approach vs neoclassical maximization; and experiments of Allais and others vs expected utility theory.