A quantum algorithm succeeds not because the superposition principle allows ‘the computation of all values of a function at once’ via ‘quantum parallelism’, but rather because the structure of a quantum state space allows new sorts of correlations associated with entanglement, with new possibilities for information-processing transformations between correlations, that are not possible in a classical state space. I illustrate this with an elementary example of a problem for which a quantum algorithm is more efficient than any classical algorithm. I also introduce the notion of ‘pseudotelepathic’ games and show how the difference between classical and quantum correlations plays a similar role here for games that can be won by quantum players exploiting entanglement, but not by classical players whose only allowed common resource consists of shared strings of random numbers (common causes of the players’ correlated responses in a game).

The major question—what is categorial analysis and how can it be reliably performed?—lies beyond the scope of this paper. Indeed, I would presume that very little can be said significantly about it in general. One's convictions on the subject have to be shown by actual performance, which is my intention in the present instance. But it may help the process of communication if I try to indicate at the beginning the general frame in which this analysis of value occurs.

In his review of my Prelude to Galileo (1981a), Ernan McMullin rejects my emendation of Pierre Duhem's “continuity thesis” wherein I develop the case for a pronounced medieval-scholastic influence on Galileo's science based on parallels between Galileo's early Latin compositions and lectures given by contemporary Jesuits at the Collegio Romano (McMullin 1983). He does so on two grounds: (1) that the evidence of derivation I provide, using textual parallels, is so strong that it refutes the claim for any intellectual influence, being a better instance of mindless copying than one of personal appropriation; and (2) that, in any event, the logical structure of the argument which I attribute to Galileo's mature work is not that of demonstration ex suppositione as understood by Aquinas, and so the example I provide of Galileo's use of suppositio “does not link him in any significant way to the specifically Thomist tradition of natural science” (1983, p. 173). An adequate reply to this critique would require the introduction of more historical evidence than would be appropriate for the pages of this journal. A few remarks, however, may be in order concerning such evidence which bears directly on McMullin's first ground, and concerning the implications of this evidence for contemporary philosophy of science, which bear on his second.

In “Events and Causality” Mark Steiner argues that though Bertrand Russell was right to claim that the laws of physics do not express causal relations, nevertheless, Russell was wrong to suppose that therefore causality plays no role in physics. I argue that Steiner misses the point of Russell's argument for the first of these claims, and because of this Steiner's argument against the second fails to controvert it. Steiner fails to see that Russell's argument against causation, is in fact an argument against the existence of causal directionality or asymmetry. Steiner gives no reason to suppose physical theory requires this asymmetry after all.

We argue that Horgan's program for nominalizing science fails, because its translation of quantitative statements destroys the inferential structures of explanations, predictions and retrodictions of nonquantitative scientific facts.

In this paper I discuss a generalization of communication theory. I sketch a model of the communication situation sufficiently general to subsume all models of particular aspects of communication. Several definitions and lines of inquiry are proposed. It will be evident that much of what I say has been influenced by Bar-Hillel (1), and also that this paper goes beyond Bar-Hillel's both in generality of scope and in details of analysis. The more general aim of the paper is to suggest a reconstruction of our intuitions regarding communication. In particular, I argue that we should drop the idea that anything is “conveyed” in communication.

There is a considerable divergence of opinion about the meaning of mathematics, and it is only with hesitation that I, as a theoretical physicist concerned mainly with geophysics, venture to discuss a matter that professional logicians differ about. Nevertheless I am concerned with the problems of the acquirement of knowledge by scientific methods, and the solutions of these problems involve pure mathematics, the validity of which one is usually willing to take for granted. But the logical schools are not so willing, and aim at demonstration. Logic must be true in all possible worlds, and all empirical propositions must be rigorously excluded. A scientist, on the other hand, is interested mainly in empirical propositions, and mathematics (with logic) is primarily a tool for investigating their relations. The proof of mathematics would therefore have interest for science, provided that the proof is sufficiently general to cover scientific requirements. If it is not, and the subject matter of the proof is restricted so that it fails to cover the scientific use of mathematics, then in its scientific application it is merely an analogy, and we are no better off than we should be if we simply took the validity of mathematics as it stands as a postulate.

“Dutch Book” arguments and references to gambling theorems are typical in the debate between Bayesians and scientists committed to “classical” statistical methods. These arguments have rarely convinced non-Bayesian scientists to abandon certain conventional practices (like fixed-level null hypothesis significance testing), partially because many scientists feel that gambling theorems have little relevance to their research activities. In other words, scientists “don’t bet.” This article examines one attempt, by Schervish, Seidenfeld, and Kadane, to progress beyond such apparent stalemates by connecting “Dutch Book”–type mathematical results with principles actually endorsed by practicing experimentalists.

The universal optimality theorem for metainduction works for epistemic agents faced with a choice among finitely many prediction methods. Eckhart Arnold and Tom Sterkenburg objected that it breaks down for infinite or unboundedly growing sets of methods. In this article the metainductive approach is defended against this challenge by extending the optimality theorem (i) to unboundedly growing sets of methods whose number grows less than exponentially in time, (ii) to sequences of methods with an application to Goodman's problem, and (iii) to infinite sets of methods whose number of predictive equivalence classes grows less than linearly in time.

In a recent paper in this journal which was part of a panel discussion of Grünbaum's philosophy of science, M. G. Evans discusses the Lorentz-Fitzgerald contraction hypothesis and related matters [2]. The purpose of this note is to clarify and correct some of the points in Evans' paper.

The claim that there are nonpurposive functional statements is critically examined by looking at nine translation schemata, several of which are drawn from recent literature. All but one or two fail, suggesting that all functional statements (a) are causal (and not about probabilities or necessary conditions), and (b) have implicit reference to goals. If so, then the possibility of nonpurposive functional statements rests squarely on the possibility of nonpurposive goals.

We are told that we live in a scientific world. All about us are the fruits of scientific research, and the products of scientific industry. But, in spite of this transformation of our material surroundings, scientific thought, or the scientific method as such, has had no effect upon the everyday thought and behaviour of our people. To be sure, along with the scientific gadgets a few scientific truths have been disseminated. They know the earth is round and moves about the sun; they could know that bacteria cause disease and that they are themselves descended from less articulate forms of animal life. Even when such conclusions are accepted, it is on the basis of authority with no understanding as to how they arose and on what basis they stand. For the large majority, science has merely acquired a cloak of respectability; it is a stronger magic than that of our forebears, and our modern alchemy is known as a powerful though mysterious source of pecuniary profit.

The traditional attitude of philosophers towards the analysis of language is that it may have some corrective value, but can make no positive contribution to philosophy. The world must be investigated in itself: an analysis of the language in which we describe it will perhaps give us greater insight into the description, but not into what is described. Many philosophers have been suspicious of language, considering it a hindrance rather than an aid in philosophical investigation. This tradition has a long history, some of whose high points we can mention briefly.

The present moment is a portentous one in the history of human relations. Only yesterday the armies of half the world were locked in a death struggle with the armies of the other half. And even now, as the representatives of the various governments gather together in attempts to organize an international State, the shadow of a weapon that threatens to end all life upon this earth lies athwart their deliberations. The moment with which we are faced is the more portentous because of the persistent hope man vainly entertains that a world of wholeness and peace will somehow issue out of these two warring and divided half-worlds. Even the student of behavior fondly believes that out of this divided world an undivided peace will come. Along with the rest of mankind even the seasoned psychiatrist fails to see that the overwhelming impetus to man's behavior—to his feeling and thinking—now stems from a social artifact of division. He does not see that, owing to a discrepancy in man's mental and social processes, the artificial world man has created is necessarily a world of conflict. In this hour of universal confusion and discord it would appear that we who study the problems of human adaptation are confronted with nothing less than a false, unilateral principle of motivation affecting the organism of man throughout.