In what follows our purpose is to make clear the reasons which lie back of Whitehead's appeal to eternal objects in his explanation of the emergence of actual entities and to show that so long as one operates within his scheme of ideas no other consistent explanation is available. A thoroughgoing reconstruction of the scheme is necessary if this presupposition is to be eliminated. If the project is successful, it will be demonstrated that the theory of actual entities provides no basis for the explanation of the emergence of novel things, which is one of the major tenets of the organic philosophy. The argument will develop by way of an analysis of the theory of “physical relatedness.”

Metaphysical problems may be solved by the methods of inference employed in the empirical sciences. So we are told by many realists and pragmatists, among whom may be mentioned Professors J. B. Pratt, William Savery, and Donald Williams. Mr. Williams and Mr. Pratt have argued for the use of inductive methods in establishing the existence of an external world. Mr. Savery has asserted that all philosophical inference as to matter of fact is inductive. This naturalistic attitude is by no means unusual—in fact it is so common in this age in which the speculations of scientists as well as their achievements have captivated the popular imagination, that even philosophers have for the most part failed to examine its validity and presuppositions. It is the purpose of this paper to present such an examination, not of the philosophic employment of inductive methods in general, but in regard to one specific problem; namely, that of the existence of an external world. What I purpose then is to present and evaluate the view that the existence of an external world may be established by inductive methods as employed in the empirical sciences.

W. V. O. Quine's well-known attack upon the analytic-synthetic distinction is held to affect only one of the two species of analytic statements he distinguishes. In particular it is not directed at and does not affect the so-called logical truths. In this paper the scope of Quine's attack is extended so as to embrace the logical truths as well. It is shown that the unclarifiability of the notion of ‘synonymy’ deprives us not only of “analytic statements that are obtainable from logical truths by the replacement of synonyms with synonyms” but of “logical truths” themselves.

In his book, The Scientific Image, Bas van Fraassen argues for an anti-realist view of science according to which the sole epistemological aim of science is to “save the phenomena”. As originally conceived, his constructive empiricism is strongly extensional, but in his account of the empirical adequacy of probabilistic theories, van Fraassen reluctantly abandons this extensional position, arguing that modal (intensional) notions are unavoidable in interpreting probability. I argue in this paper that van Fraassen has not presented the strongest possible case for a fully extensional account of empirical adequacy. On the present account, a probabilistic theory is empirically adequate just in case there is no theory that has a higher likelihood relative to all the phenomena in the actual world. I prove that a theory is empirically adequate if and only if the probability attributed to each observable event that occurs in the actual world is its limiting relative frequency. Thus, in so far as one is concerned with the empirical adequacy (rather than with the literal truth) of probabilistic theories, strict relative frequencies provide an adequate basis for “interpreting probability”.

Probabilistic theories are treated in a genuine measurement context. In this connection I distinguish between worlds that are “strongly infinite” and worlds that are only “weakly infinite”. It is characteristic of the former worlds that there is no limit to the precision of actual measurements. I show by example that in some “strongly infinite” worlds, theories will be empirically adequate only if observables are represented by continuous (rather than discrete) random variables. The range of such examples is clarified by a theorem which states necessary and sufficient conditions under which the “phenomena can be saved” without recourse to continuous random variables and real numbers.

Although there has been some discussion in the literature of Bas van Fraassen's modal interpretation of Quantum Mechanics, it has for the most part been concentrated on difficulties that van Fraassen's viewpoint shares with those of some other authors, including Kochen, Dieks, and Healey. van Fraassen's approach has, however, some problems of its own; in this note we want to focus on what seems to us to be one of the most serious of these. The difficulty concerns immediately repeated non-disturbing measurements of the same observable on a single system. As is well known, von Neumann's Projection Postulate guarantees that such measurements will always give the same outcome; likewise, in the approaches of the “modalists” mentioned above, such ‘consilience of repeated measurements’ is in one way or another built into the formalism. By contrast, we shall argue, van Fraassen's modal interpretation neither guarantees this result nor adequately explains why it is unnecessary to do so.

Usual derivations of Lüders's projection rule show that Lüders's rule is the rule required by quantum statistics to calculate the final state after an ideal (minimally disturbing) measurement. These derivations are at best inconclusive, however, when it comes to interpreting Lüders's rule as a description of individual state transformations. In this paper, I show a natural way of deriving Lüders's rule from well-motivated and explicit physical assumptions referring to individual systems. This requires, however, the introduction of a concept of individual state which is not standard.

Philip Kitcher and Wesley C. Salmon have edited an important anthology of new papers on scientific explanation, a central problem—possibly the central problem—in the theory of science (Kitcher and Salmon 1989). Their collection begins with a comprehensive essay by Salmon that attempts to trace the development of work on this issue from Hempel and Oppenheim (1948) to the present. The University of Minnesota Press has published this article as a separate volume (Salmon 1990), which it is promoting as “a definitive introduction” to this area of inquiry. Apart from its preface and indices, the Salmon volume is identical with the original essay.

Nearly a half century ago, Thomas Kuhn, Paul Feyerabend, Stephen Toulmin, Norwood Russell Hanson, and others issued a challenge to us philosophers of science to make our field more relevant to actual science. That challenge, over time, has elicited a number of useful responses but very few efforts to situate science within its wider social context when philosophizing about science. The unit of analysis for philosophy of science has tended to remain science-in-a-vacuum. I consider the justifications we offer for this failure, our resources for change, and our prospects if we do change.

What is metaphysics? There is real danger of taking the meaning of this term too much for granted, and of leaning too heavily upon an undefined word in the very act of dismissing metaphysics as word jugglery. Metaphysics is not, as I conceive it, the study of the wholly transcendent or supersensible. It may sometimes have been so conceived, and this is, indeed, one reason why some of its alleged results are so unsatisfactory—or, as positivists would say, meaningless. Such a meaningless “metaphysical” idea is the mediaeval doctrine of God as a power acting upon the world but not reacted upon by it, as purposive but non-temporal, loving but “impassive,” etc. Such is the windowless monad of Leibniz, connected with other monads only by pre-established harmony. Such is the Aristotelian idea of substance as that in which other things inhere but which itself is in nothing (apparently not even in the world or nature). The history of metaphysics is, indeed, strewn with failures to achieve meaning. But does this mean that metaphysics has scored no successes? Surely we must remember that human success is invariably of the fumble-and-correction type. Ideas such as those mentioned may be meaningless as they stand, and yet have potential meaning in that some modification of them might render them significant conceptions. We must also remember that mankind now possesses new instruments of logical analysis, and that these instruments may prove useful in metaphysics—not, as logical positivism holds, with the result of banishing all metaphysical ideas, but of correcting their erroneous aspects.