Joseph Schumpeter
Read this biographical article about Joseph Schumpeter. It gives some interesting context to his innovations in economic thought, which were largely eclipsed by the rise of Keynesian economics.
Work
Business Cycles
In the theory of business cycles, where he was following neither Leon Walras nor Keynes, Schumpeter starts, in his The Theory of Economic Development (1911), with a treatise of circular flow which, excluding any innovations and innovative activities, leads to a stationary state. The stationary state is, according to Schumpeter, described by Walrasian equilibrium. And the hero of his story, is, in fine Austrian fashion, the entrepreneur.
A noticed characteristic of Business Cycles: A Theoretical, Historical, and Statistical Analysis of the Capitalist Process (1939) is his attempt to turn business cycle patterns into predictive scientific wave theories borrowed from physics. As Schumpeter wrote, "Barring very few cases in which difficulties arise, it is possible to count off, historically as well as statistically, six Juglars [8-10-year business cycles] to a Kondratieff [50-60 years] and three Kitchins [40 months] to a Juglar - not as an average but in every individual case". Why this was so, he admitted, "is indeed difficult to see".