The present crisis in the first decades of the twentieth century has a mirror image from a century ago. The crisis of the twenty-first century grows out of the last decades of the twentieth century, whereas the last decades of the nineteenth set the stage for the bloody global warfare of the twentieth century. It also served as the foundation for the emergence of modern social thought in the twentieth century because of the momentous social changes of the time. The most visible characteristic of modern social science is its establishment in the academy as disciplines such as anthropology, political science, sociology, and the like. These academic disciplines grew from the work of theorists in Europe and America. This chapter treats the American tradition that is associated with the seminal works of Charles Sanders Peirce, and Chapter 5 analyzes the European tradition.