Joseph Alois Schumpeter (1883-1950) was an Austrian-trained economist, economic historian, and author. He is regarded as one of the 20th century's greatest intellectuals. Schumpeter is best known for his theories on business cycles and the development of capitalist economies, and for introducing the concept of entrepreneurship. For Schumpeter, the entrepreneur was the cornerstone of capitalism—the source of innovation, which is the vital force driving a capitalist economy.