Discussions of the interpretation of quantum theory are at present obstructed by (1) the increasing axiomania in physics and philosophy which replaces fundamental problems by problems of formulation within a certain preconceived calculus, and (2) the decreasing (since 1927) philosophical interest and sophistication both of professional physicists and of professional philosophers which results in the replacement of subtle positions by crude ones and of dialectical arguments by dogmatic ones. More especially, such discussions are obstructed by the ignorance of both opponents, and also defenders of the Copenhagen point of view, as regards the arguments which once were used in its defence. The publication of Bunge's Quantum Theory and Reality and especially of Popper's contribution to it are taken as an occasion for the restatement of Bohr's position and for the refutation of some quite popular, but surprisingly naive and uninformed objections against it. Bohr's position is distinguished both from the position of Heisenberg and from the vulgarized versions which have become part of the so-called “Copenhagen Interpretation” and whose inarticulateness has been a boon for all those critics who prefer easy victories to a rational debate. Einstein's main counterargument is discussed, and Bohr's refutation restated. The philosophical background and earlier forms of Bohr's views are stated also. Considering that these views are more detailed, better adapted to the facts of the microdomain than any existing alternative it follows that fundamental discussion must first return to them. Their uniqueness is not asserted, however. Here the author still maintains that a hundred shabby flowers are preferable to a single blossom, however exquisite. But a hundred shabby flowers plus an exquisite blossom are more desirable still.

After precisely specifying the thesis of the causal theory of time, Grünbaum's program developed to support this thesis is examined. Four objections to his definition of temporal order in terms of a more primitive causal relation are put and held to be conclusive. Finally, the philosophical arguments that Grünbaum has proposed supporting the desirability of establishing a causal theory of time are shown to be either invalid or inconclusive.

An objective and relational theory of local time is expounded and its philosophical implications are discussed in Sect. 2. In Sect. 3 certain physical and metaphysical questions concerning time are taken up in the light of that theory.

This portion of the essay concludes a two-part paper, Part I of which appeared in an earlier issue of this Journal. Part II begins with a careful study of the quantum description of real experiments in order to motivate a proposal that two distinct quantum theoretical measurement constructs should be recognized, both of which must be distinguished from the concept of preparation. The different epistemological roles of these concepts are compared and explained. It is then concluded that the only possible type of “quantum measurement theory” is one of little metaphysical interest and that quantum measurement seems problematical only when viewed from an overly narrow classical perspective.

1. Introduction. Professor Nagel's account of the “cognitive status” of scientific theories has been attacked by P. K. Feyerabend [5] and M. B. Hesse [8] in terms of his alledgedly misguided distinction between experimental laws and theories. The difficulty lies, these critics agree, in Nagel's attempt to find a stable basis for scientific theories in an observational basis of experimental laws. Both Feyerabend and Hesse note the vacillation in Nagel's account of the stability of the meaning of experimental terms and in his discussion of the status of observational as opposed to theoretical terms. They find Nagel too “positivistic” and see as a first step toward a more adequate account of scientific theories the abandonment of the theoretical-observational dichotomy as having more than a pragmatic significance. Nagel's discussion of the theoretical-observational dichotomy is, I agree, inadequate in certain respects. I shall, however, suggest a quite different remedy from those of Feyerabend and Hesse, one that depends neither on a phenomenalistic reduction of theoretical entities nor on a blurring of the theoretical-observational dichotomy.