Although Schumpeter encouraged some young mathematical economists and was even the president of the Econometric Society (1940–41), Schumpeter was not a mathematician, but rather an economist, and tried instead to integrate history and sociological understanding into his economic theories. Some argue that Schumpeter's ideas on business cycles and economic development could not be captured in the mathematics of his day – they need the language of non-linear dynamical systems to be partially formalized.[citation needed]