Thus in contemporary quantum theory it seems that the world must be divided into a wavy "quantum system," and a remainder which is in some sense "classical." The division is made one way or another, in a particular application, according to the degree of accuracy and completeness aimed at. For me it is the indispensability, and above all the shiftiness, of such a division that is the big surprise of quantum mechanics. It introduces an essential ambiguity into fundamental physical theory, if only at a level of accuracy and completeness beyond any required in practice. It is the toleration of such an ambiguity, not merely provisionally but permanently, and at the most fundamental level, that is the real break with the classical ideal. It is this rather than the failure of any particular concept such as "particle" or "determinism." In the remainder of this essay I will outline a number of world views with physicists have entertained in trying to digest this situation.
Drives me effin' mental that one.