Thorstein Veblen (1857 -1929) was a Norwegian-American sociologist and economist. He received his Ph.D. in 1884 at Yale University. In 1892, he became a professor at the University of Chicago. The Theory of the Leisure Class (1899) is his most well known work. Veblen developed a 20th century evolutionary economics based upon Darwinian principles and new ideas emerging from anthropology, sociology, and psychology. An excerpt from the Introduction reads, "What are the terms on which peace at large may hopefully be installed and maintained? What, if anything, is there in the present situation that visibly makes for a realisation of these necessary terms within the calculable future? And what are the consequences presumably due to follow in the nearer future from the installation of such a peace at large? And the answer to these questions is here sought not in terms of what ought dutifully to be done toward the desired consummation, but rather in terms of those known factors of human behaviour that can be shown by analysis of experience to control the conduct of nations in conjunctures of this kind."