The course aims to offer a critical description of the historical development of theories which dealt with the role of firm in the economic system. Starting point is the analysis of entrepreneur according to classical theories developed by Smith, Say, Babbage, Marx, completing this first part with Schumpeter's analysis of entrepreneur-innovator and Marshallian firm theory. The course continues approaching structural firm transformations after the second industrial revolution and the spread of organizational thought. Taylor and Fayol organizational theories are so analysed, as well as new organizational theories, from neoevolutionary and behaviourist ones to Baumol, Coase and Williamson contributions.