For a long time, it has not only been sociologists, historians, and some heterodox economists who criticize the model of complete rationality. For the increasingly influential branch of behavioral economics, it is precisely the frequently observed "irrationality" of economic actors that constitutes the central point of departure for analysis. Anyone who still searches for the economically rational human being, the homo oeconomicus, will find him, among other places, in financial advice literature. However, in this particular literary genre, unlike his scholarly counterpart, he does not embody an abstract principle of economic action or a hypothesis to be empirically tested concerning the behavior of real actors. Rather, he presents himself as a normative ideal and model to which "smart," "forward-looking," and "eager-to-learn" readers are encouraged to orient themselves. Philipp Neeb examines a corpus of approximately 200 historical and contemporary works of financial advice in German and English regarding the question of how norms and criteria of rational decision-making in dealing with money have been communicated under specific historical conditions. The underlying perspective is that of the sociology of knowledge. The specific selectivity with which financial advice literature asks for criteria of rationality for monetary decisions corresponds, according to the author's thesis, to an overemphasis of economic roles and economic concerns over all other relevant roles and life contexts. It is thus simultaneously an expression of a popular reflection theory of the economy.