Preface; First lecture: rationality in decision making: 1.1. Development of the concept of rationality; 1.2. Contemporary choice theory; 1.3. The plurality of rationalities; 1.4. The history reviewed; 1.5. Empirical tests of theories; 1.6. References; 1.7. Debate of the first lecture Andrea Ichino, Luigi Pasinetti; Second lecture: the role of organisations in an economy: 2.1. Organisations and markets; 2.2. Altruism and organisational identification; 2.3. Organization, management and the economy; 2.4. Conclusion; 2.5. References; 2.6. Debate of the second lecture; Third lecture: empirical evidence for economics: 3.1. How much theory, and how concrete; 3.2. Implications of data for theory; 3.3.The sources of data on economic processes; 3.4. Seeking empirical data outside the business firm; 3.5. Decision making in the business firm: case studies; 3.6. Economic history; 3.7. Data from 'applied' economics; 3.8. Survey techniques; 3.9. Conclusion; 3.10. References; 3.11. Debate of the third lecture Fabio Arcangeli, Anna Grandori, Andrea Ichino, Daniele Terlizze; Comments: Claudio Dematte, Massimo Egidi, Robert Marris, Aldo Montesano, Riccardo Viale; Simon's reply; Herbert A. Simon's autobiographical sketch.