There are three intentions (aims) of this paper. First, to focus the attention of readers to three not so well known and least frequently quoted by economists of Mises’s books, namely his 1957 Theory and History: An Interpretation of Social and Economic Evolution, and two closely related The Ultimate Foundation of Economic Science: An Essay on Method (1962), and Epistemological Problems of Economics (1933/1960). The second aim is to outline Mises’s legacy, presented in the form of eleven dimensions of Mises’s (...) Intellectual Universe. The eleven dimensions of Mises’s system are: Economics as science, praxeology, and human action; Methodological dualism; Judgments of value and subjectivism; Individualism; Rationalism and human action; Consumer; Cooperation and competition; Thymology; Mathematics in economics; Predictions; and Historical analysis. Third, to present the main issues related to Mises’s concept of rationalism. There is no mention of Ludwig von Mises’s concept of rationality in a great number of books and papers dealing with the understanding of the rationality of human beings. The concept of rationality proposed by Ludwig von Mises is neglected by modern researchers and economists of different schools, but especially by mainstream economists. A good example of neglecting Mises’s ideas on rationality is the latest book by Nassim Taleb, Skin in the Game: Hidden Asymmetries in Daily Life. Although Taleb’s proposition of understanding rationality and irrationality is very close to the concept of Mises, he does not refer to Mises’s work at all. No single word on Mises in that book! (shrink)