Interpretations, or generalizations, of quantum theory that are applicable to cosmology are of interest because they must display and resolve the “paradoxes” directly. The Everett interpretation is reexamined and compared with two alternatives. Its “metaphysical” connotations can be removed, after which it is found to be more acceptable than a theory which incorporates collapse, while retaining some unsatisfactory features.

In spite of the fact that the Neyman–Pearson theory of testing is the official theory of statistical testing, most research publications in the social sciences use a pattern of inductive reasoning that is characteristic of Fisherian tests of significance. The exact structure and rationale of this pattern of reasoning is widely misunderstood. The goal of the paper is to describe precisely the pattern and its rationale, and to show that while it is far more cogent than Fisher's critics have realized, it does not logically sustain the inferences it sanctions.

This paper argues that if a person's beliefs are idealized as a set of sentences (theoretical, observational, and mixed) then the device of Ramsey sentences provides a treatment, of the mind-brain problem, that has at least four noteworthy characteristics. First, sentences asserting correlations between one's own brain state and one's own “private” experiences are, on such treatment, reconstrued as neither causal, coreferential, nor as meaning postulates, but as clauses in an overall hypothesis (Ramsey sentence) whose only nonlogical constants have “private” meanings. Second, sentences asserting psycho-physical correlations in general, or in other individuals, remain theoretical and susceptible to scientific reduction, though not prejudged to be so. Third, communication between persons having mutually exclusive, “private,” observational vocabularies can be made intelligible. Fourth, it becomes possible in principle (though not necessary) that the world could ultimately be given a total description in a scientific language, Lφ, without mental primitives. However, such a language would be susceptible to interpretation by a given individual using a metalanguage whose primitives (not among those of Lφ) were privately observational to that individual. His procedure in accomplishing such an interpretation would be to construct a Tarskian truth definition in a metalanguage MLφ and then to incorporate it, by Ramsifying its descriptive terms, in his own overall Ramsey sentence. The physical language, Lφ, while not containing a person's primitives, would, of course, be able to define their physical correlates, thus providing a certain sort of mutual mirroring, and a certain sort of relativity.

The basic task of the essay is to exhibit science as a rational enterprise. I argue that in order to do this we need to change quite fundamentally our whole conception of science.

Today it is rather generally taken for granted that a precondition for science to be rational is that in science we do not make substantial assumptions about the world, or about the phenomena we are investigating, which are held permanently immune from empirical appraisal. According to this standard view, science is rational precisely because science does not make a priori metaphysical presuppositions about the world forever preserved from possible empirical refutation. It is of course accepted that an individual scientist, developing a new theory, may well be influenced by his own metaphysical presuppositions. In addition, it is acknowledged that a successful scientific theory, within the context of a particular research program, may be protected for a while from refutation, thus acquiring a kind of temporary metaphysical status, as long as the program continues to be empirically progressive. All such views unite, however, in maintaining that science cannot make permanent metaphysical presuppositions, held permanently immune from objective empirical evaluation. According to this standard view, the rationality of science arises, not from the way in which new theories are discovered, but rather from the way in which already formulated theories are appraised in the light of empirical considerations. And the fundamental problem of the rationality of science—the Humean problem of induction—concerns precisely the crucial issue of the rationality of accepting theories in the light of evidence.

In this essay I argue that this widely accepted standard conception of science must be completely rejected if we are to see science as a rational enterprise. In order to assess the rationality of accepting a theory in the light of evidence it is essential to consider the ultimate aims of science. This is because adopting different aims for science will lead us, quite rationally, to accept different theories in the light of evidence. I argue that a basic aim of science is to explain. At the outset science simply presupposes, in a completely a priori fashion, that explanations can be found, that the world is ultimately intelligible or simple. In other words, science simply presupposes in an a priori way the metaphysical thesis that the world is intelligible, and then seeks to convert this presupposed metaphysical theory into a testable scientific theory. Scientific theories are only accepted insofar as they promise to help us realize this fundamental aim.

At once a crucial problem arises. If scientific theories are only accepted insofar as they promise to lead us towards articulating a presupposed metaphysical theory, it is clearly essential that we can choose rationally, in an a priori way, between all the very different possible metaphysical theories that can be thought up, all the very different ways in which the universe might ultimately be intelligible. For holding different aims, accepting different metaphysical theories conceived of as blueprints for future scientific theories will, quite rationally, lead us to accept different scientific theories. Thus it is only if we can choose rationally between conflicting metaphysical blueprints for future scientific theories that we will be in a position to appraise rationally the acceptability of our present day scientific theories. We thus face the crucial problem: How can we choose rationally between conflicting possible aims for science, conflicting metaphysical blueprints for future scientific theories? It is only if we can solve this fundamental problem concerning the aims of science that we can be in a position to appraise rationally the acceptability of existing scientific theories.

There is a further point here. If we could choose rationally between rival aims, rival metaphysical blueprints for future scientific theories, then we would in effect have a rational method for the discovery of new scientific theories! Thus we reach the result: there is only a rational method for the appraisal of existing scientific theories if there is a rational method of discovery.

I shall argue that the aim-oriented theory of scientific inquiry to be advocated here succeeds in exhibiting science as a rational enterprise in that it succeeds in providing a rational procedure for choosing between rival metaphysical blueprints: it thus provides a rational, if fallible, method of discovery, and a rational method for the appraisal of existing scientific theories—thus resolving the Humean problem.

In Part I of the essay I argue that the orthodox conception of science fails to exhibit science as a rational enterprise because it fails to solve the Humean problem of induction. The presuppositional view advocated here does however succeed in resolving the Humean problem. In Part II of the essay I spell out the new aim-oriented theory of scientific method that becomes inevitable once we accept the basic presuppositional viewpoint. I argue that this new aim oriented conception of scientific method is essentially a rational method of scientific discovery, and that the theory has important implications for scientific practice.

It is argued that the main problem with “the problem of the direction of time” is to figure out what the problem is or is supposed to be. Towards this end, an attempt is made to disentangle and to classify some of the many issues which have been discussed under the label of ‘the direction of time’. Secondly, some technical apparatus is introduced in the hope of producing a sharper formulation of the issues than they have received in the philosophical literature. Finally, some tentative suggestions about the central issues are offered. In particuar, it is suggested that entropy and irreversibility are much less crucial to the central issues than most philosophers would have us believe. This suggestion is not made because of any firm conviction of its correctness but rather because it helps to focus the discussion on some basic but long neglected assumptions which underlie traditional approaches.

It is argued that two aspects of the progress of mature science characterize, at least in combination, no other fields; hence, that these aspects can usefully serve as a demarcation criterion. Scientific progress is: (1) cumulative, regardless of crisis or revolution, from the viewpoint of concrete applications; (2) capable of unrestricted growth towards universal coerciveness of argument and evidence. Before these aspects of progress are discussed, some clarifications are made and corrections offered to Kuhn's view of the nature of scientific progress across revolutions; afterwards, the suggested criterion is used to distinguish, concretely, various fields from science. Finally, it is shown that the “style” of scientific progress is not a useful demarcation criterion.

The “Ignorance Interpretation” of quantum mechanical mixtures holds, roughly, that whenever a system S belongs to an ensemble, which is represented by a mixed statistical operator U = Σpi P[ψi] (0 ≤ pi ≤ 1, Σipi = 1, P[ψi] is the projection operator for the state ψi), then S is in some pure state, although we are ignorant as to which one. It has been concluded, e.g. by van Fraassen, that “the ignorance interpretation is untenable,” and he presumably favors adopting “the position that mixtures of pure states are themselves new states ... to say that a system is in a proper mixture is to say that it is not in a pure state.” I wish to argue in this paper that there are no good grounds for rejecting the ignorance interpretation.

This paper presents parts of a theory of radical translation with applications to the problem of construing reference. First, in sections 1 to 4 the general standpoint, inspired by Goodman's approach to induction, is set forth. Codification of sound translational practice replaces the aim of behavioral reduction of semantic notions. The need for a theory of translational projection (manual construction on the basis of a finite empirical correlation of sentences) is established by showing the anomalies otherwise resulting (e.g. from Quine's position). Then in section 5 a partial characterization of what constitutes an “admissible translation manual” is developed in the form of rules of translational projection governing correspondence of sentence-parts of a language-pair. Finally, in section 6, we give applications of the theory to the problem of construing reference. The general rules of section 5 suffice to rule out deviant referential schemes which have been held inscrutable alternatives to standard schemes.

In Part I (Philosophy of Science, Vol. 41 No. 2, June, 1974) it was argued that in order to rebut Humean sceptical arguments, and thus show that it is possible for pure science to be rational, we need to reject standard empiricism and adopt in its stead aim oriented empiricism. Part II seeks to articulate in more detail a theory of rational scientific discovery within the general framework of aim oriented empiricism. It is argued that this theory (a) exhibits pure science as a rational enterprise (b) enables us to resolve problems associated with the key notions of simplicity and intelligibility (c) has important implications both for philosophy of science and for scientific practice itself.

In this paper we show how a form of Maxwellian Demon can be interpreted as a computing automaton. We then point out some ways in which the Demon systems can be generalized, and briefly describe and discuss the properties of some of the corresponding automata. It is shown that a generalized Maxwell Demon system can carry out arbitrary Turing computations.

Finally, the association developed between classes of thermodynamic systems and classes of computational systems is employed to suggest approaches to some fundamental problems of the relationships between computation, the information obtained by computation, and energy.

A brief discussion is offered of what it means to say that a set of statements provides D-N explanation with special emphasis given to approximative D-N explanation. An idealized theory is seen to provide approximative D-N explanation. An ideal case provides explanation only if postulates are offered which connect the ideal antecedent condition with actual conditions. Such postulates will help in accounting for deviations between what the consequent of the ideal case entails and what actually occurs. Three ways are presented for deciding on the acceptability of idealizations: (i) as actual conditions more closely approximate the ideal antecedent conditions specified in an ideal case, the more closely actual cases ought to approximate the consequent of the ideal case; (ii) the additional postulates connecting ideal antecedent conditions with actual conditions ought to account for deviations between what is entailed by an idealized theory and what actually occurs ; and (iii) an idealized theory is explained by a more general theory when certain state variables in the more general theory are given extreme values. It is argued that (iii) is not a necessary condition for the acceptability of idealizations.

It is commonly thought that the dispositional view of purposiveness is itself incompatible with the programmatic claims of neurophysiologists. In this paper, various versions of four arguments for this incompatibility are examined, and rejected as unsound. Central to the argument is a rough sketch of a “mechanistic” position which seems clearly compatible with a dispositional view of purposiveness.

This paper states two sets of axioms sufficient for extensive measurement. The first set, like previously published axioms, requires that each of the objects measured must be classifiable as either greater than, or less than, or indifferent to each other object. The second set, however, requires only that any two objects be classifiable as either indifferent or different, and does not need any information about which object is greater. Each set of axioms produces an extensive scale with the usual properties of additivity and uniqueness except for unit. Moreover, the axioms imply Weber's Law: whether two objects are indifferent depends only upon the ratio of their scale values.

This paper takes the first steps in the construction of a theory of event identity as that theory applies to historical sentences. The theory is extensional throughout. Following statements of criteria of adequacy for the construction, Davidson's method of regimenting sentences is adopted in order to allow for variables ranging over events. Events in this theory are only partially construed, that is, to the extent of treating them as concrete individuals rather than as classes or repeatable universals. The paper concludes with a statement of several theorems and definitions and an example of how the theory works.

In his valuable book [3], Israel Scheffler presents an extended critique of Thomas Kuhn's philosophy of science. Scheffler argues against Kuhn's “main thesis,” namely that “... paradigm change in science is not generally subject to deliberation and critical assessment” ([3], p. 89). Scheffler does recognize, though, that there are important elements of Kuhn's view that themselves seem to conflict with this “main thesis.” For these elements seem to make possible deliberation, critical assessment, and objectivity in the discussion of scientific paradigms. So it appears from Scheffler's critique that Kuhn's position is inconsistent. The puzzle is compounded by Kuhn's admission—indeed, insistence—that his book does contain “a preliminary codification of good reasons for theory choice. These are ... reasons of exactly the kind standard in philosophy of science: accuracy, scope, simplicity, fruitfulness, and the like” ([1], p. 231). In his recent reply to (and further critique of) Kuhn, Scheffler quotes this passage from Kuhn and says: “If these reasons are not ... to be construed as utterly free of all constraints or themselves paradigm-dependent, then they allow the comparison of rival paradigms and make paradigm debates intelligible. Such intelligibility is, however, at odds with Kuhn's statement that the proponents of competing paradigms ‘will inevitably talk through each other’” ([4], p. 369). In this interchange between Scheffler and Kuhn, one gets the impression of people, if not paradigms, talking “through each other.” I think that this nonmeeting of minds is due to interpreting Kuhn as an opponent of objectivity when in fact he is not an opponent but a proponent. It is this misinterpretation which produces the apparent inconsistency in Kuhn's position. In this paper I suggest a way of understanding Kuhn which resolves this apparent inconsistency in his work and might help to focus discussion on the real issue between Kuhn and many of his critics. This suggestion has the crucial consequence of shifting the focus from objectivity to the real issue, namely truth.

This paper presents a new formal model for D–N explanation that gives intuitive criteria of acceptability, avoids the known trivializations, and links explanation with confirmation theory. Although set in the twenty-five year tradition of attempts to formalize D–N explanation, it proposes a new direction for the model that is to be distinguished from the syntactical and informational approaches by its introduction of restrictions which derive from the use which the D–N model can have in hypothesis testing. This model, illustrating the verificational approach, revises the classic H–O requirements and amends the notion of partial self-explanation to meet a criticism to which the H–O notion is vulnerable.

An inductive method Cλ in the λ-system of Carnap [1] is immodest, on evidence e, iff its estimate, on e, of its own accuracy is higher than its estimate, on e, of the accuracy of any rival method Cλ′. Immodesty seems to be a condition of stable trust: if you trusted a modest Cλ, you should start by trusting its advice to replace it by a rival that it estimates to be more accurate. One might guess that any Cλ would be immodest on any evidence. But in [2] I proved that, under a certain accuracy measure taken from Carnap [1], §§ 20–21, there would be exactly one immodest Cλ. Unfortunately, that one sometimes turns out to be C0 (the straight rule); and since nobody in his right mind would trust C0 we are then left with no acceptable Cλ. Stephen Spielman [3] has proposed a remedy: an estimate of accuracy, on evidence e, should disregard accuracy under circumstances that are ruled out by e. Spielman proves that if this change is made, any Cλ is immodest on any evidence.

Axiomatizations of measurement systems usually require an axiom—called an Archimedean axiom—that allows quantities to be compared. This type of axiom has a different form from the other measurement axioms, and cannot—except in the most trivial cases—be empirically verified. In this paper, representation theorems for extensive measurement structures without Archimedean axioms are given. Such structures are represented in measurement spaces that are generalizations of the real number system. Furthermore, a precise description of “Archimedean axioms” is given and it is shown that in all interesting cases “Archimedean axioms” are independent of other measurement axioms.