Like many influential volumes, The Political System has become a prisoner of its interpretive history, but it is ironic that little attention has been given to the text itself and to the organization of the argument as well as to the intellectual environment in which Easton''s systems concept was formulated. To some extent, the idea of a political system was rooted in the heritage of Charles Merriam’s school at the University of Chicago, but it also emerged from both Easton’s early education and his participation in interdisciplinary academic forums at Chicago. Although the commitment to a science of politics was part of the Merriam legacy, the traditional image of science had lost meaningful content. A new image was, however, being advanced by émigré logical positivists and their supporters at Chicago, but at the same time this image was under siege by another group of influential European émigré political theorists. It is terms of this context that we must approach the text of Easton’s book and seek to recover the origins of the systems concept.