This-study examines the views of F. A. Hayek on the role of reason in human affairs. The author explicates certain elements of Hayekian theory that bear on this issue-his views on the nature of mind, rules, law, and cultural evolution-and discusses the characteristics of both the constructivist and critical kinds of rationalism Hayek identifies. She then examines the views of various critics who have challenged Hayek\u27s argument. She concludes that, contrary to certain critics, 1) the distinction he draws between constructivist and critical rationalism is meaningful and that the two kinds of rationalism appear to be related to certain political views; 2) whether Hayek, despite his criticism of the constructivistic conceit, should himsel...