Economia aziendale and Betriebswirtschaftslehre as independent sciences of the firm

From end 18th century onwards, a peculiar approach was born in Continental Europe as far as the study of the firm is concerned. That approach, later on a tradition, was born as a rebellion against the two most important economic schools of that era, i.e. Marxism on one side, marginal economics on the other.
Also building on previous scholars, Schmalenbach proposed the study of the firm as such, intended as a productive agent oriented to income, the same income being -at the same time- the very goal and the economic quantity assigning value to capital. Nicklish proposed on his turn a unified treatment, joining together the economy of families and firms, connected by the markets for goods, labour, and the financial one.
At the end of the story, originally unifying the Italian tradition in the field, and the German one, Zappa gave life to a whole field of studies, synthesizing the life and relationships of the very economic agents: families, firms, and the State.