This paper is concerned with the description of the process of measurement within the context of a quantum theory of the physical world. It is noted that quantum mechanics permits a quasi-classical description (classical in the limited sense implied by the correspondence principle of Bohr) of those macroscopic phenomena in terms of which the observer forms his perceptions. Thus, the process of measurement in quantum mechanics can be understood on the quasi-classical level by transcribing from the strictly classical observables of Newtonian physics to their quasi-classical counterparts the known rules for the measurement of the former. The remaining physical problem is the delineation of the circumstances in which the correlation of a peculiarly quantum mechanical observable A with a classically measurable observable B can result in a significant measurement of A. This is undertaken within the context of quantum theory. The resulting clarification of the process of measurement has important implications relative to the philosophic interpretation of quantum mechanics.

In this article the question is raised whether philosophers, studying Humean problems, might profit from the empirical findings of contemporary psychology. A text from Hume's Treatise of Human Nature is analyzed in an attempt to find out (1) whether his problems are open to empirical testing. Each sentence in the text is classified into normative, declarative, analytic and synthetic. A prevalence of declarative, synthetic sentences is found. Further, the question is examined (2) whether contemporary empirical psychology has contributed to the testing of Hume's hypotheses. The answer is affirmative for some of the statements, and it is suggested that philosophical discussions around these problems should not be carried out as if psychological research were irrelevant.

The views of some historians and philosophers of history as to the possibility of fruitful historical generalization seem at odds with the underlying methodology of the other social sciences. A formal model of the world historical process is here presented within which this apparent contradiction is seen to be resolvable in terms of modern theories of probability and stochastic processes. This is done by giving rigorous form to procedures and statements in the social sciences. A formal treatment of the dependence of an investigation in one discipline on previous studies both in that area and in other social and natural sciences then follows naturally.

It has become customary in modern behavioristics to speak of stimuli as though they elicit responses from organisms. But logically this is absurd, for analysis of the grammatical roles of stimulus and response concepts shows that stimuli and responses differ in logical type from causes and effects. The “S elicits R” formula thus stands revealed as elliptical for a more complicated form of assertion. The trouble with this ellipsis, however, is that by suppressing vital components of formal structure in behavioral principles, it has led to gratuitous assumptions about the environmental antecedents of behavior and seriously undermined the ability of behavior theory to assimilate the “higher mental processes.”

Terminology and symbolism are introduced, which facilitate the precise statement of propositions concerning the action of mind on body. The minimal meaning of “the action of mind on body” is contrasted with some of the more radical interactionistic positions to be found in the literature. These more radical positions are defined in precise formulations. It is noted that radical interactionism, or “exceptionalism” as it is here called, is a contingent, empirically-decidable issue which is quite independent of metaphysical views regarding “mind” and “matter.” For that very reason it should not be the object of special philosophic concern.