Current discussions of science—both popular and philosophical—often represent the development of science in our civilization as a gradual process of purification from superstitious, religious, and metaphysical elements. This purification is usually presumed to be complete by now—although there may be occasional lapses on the part of individual scientists. That science has changed in character over the centuries is a truism; that it has increasingly loosened ancient ties with magic, religion, and speculative philosophy is an easily substantiated historical thesis. This much admitted, however, an interesting question remains over for discussion: is science by its very nature independent of philosophy? This question has only as much meaning as its two key words (“science” and “philosophy”). According to one common view, “science” would signify some cumulative heritage of methods, principles, and results, while “philosophy” would signify a certain tradition of writings in which the later constantly refer to the earlier, but which otherwise exhibit no discernible uniformity of methods, principles, or results. On this view, then, science is essentially monistic while philosophy is essentially pluralistic.

In this paper, I develop a naturalistic conception of evolutionary progress. I argue that the Waddingtonian notion of adaptability can be embedded meaningfully into a framework which views living things as nonequilibrium structures. This thermodynamic interpretation places great emphasis on the dynamics of environmental change, whereas the classical conceptions are based on equilibrium conceptions of the evolutionary process. What improves in evolution is the ability of living things to stay alive in increasingly heterogeneous environments.

Science progresses if we succeed in rendering the objects of scientific inquiry more comprehensively or more precisely. Popper tries to formalize this venerable idea. According to him the most comprehensive and most precise description of the world is given by the set T of all true statements. A hypothesis comes the closer to T, or has the more verisimilitude, the more true consequences and the fewer false consequences it implies. Popper proposes to order hypotheses by the inclusion relations between the sets of their true and of their false consequences (“truth contents” and “falsity contents”). A partial ordering would permit one to decide whether the substitution of theory t1 by t2 represents scientific progress. But because of the logical relations between the elements of the sets of logical consequences, or contents, false hypotheses cannot be compared. As our theories usually turn out to be false sooner or later, they can seldom be compared as to their verisimilitude and when they can, the result depends only on which theory implies the other and on their truth-values. Popper even tries to define a measure of verisimilitude on the partial ordering. It has to fail for the same reason. In addition he tries to relativize the concept of a content and fails. What is more, any attempt at defining a measure of better or worse correspondence to the whole truth must fail, as there is no justification for saying that any true primitive sentence asserts as much about reality as some other primitive sentence, or more.

On many science-related policy questions, the public is unable to make informed decisions, because of its inability to make use of knowledge obtained by scientists. Philip Kitcher and James Fishkin have both suggested therefore that on certain science-related issues, public policy should not be decided on by actual democratic vote, but should instead conform to the public’s counterfactual informed democratic decision (CIDD). Indeed, this suggestion underlies Kitcher’s specification of an ideal of a well-ordered science. This article argues that this suggestion misconstrues the normative significance of CIDDs. At most, CIDDs might have epistemic significance, but no authority or legitimizing force.

Various fault modes of determinism in classical physics are outlined. It is shown how quantum mechanics can cure some forms of classical indeterminism.

In discussion of mechanisms, philosophers often debate about whether quantitative descriptions of generalizations or qualitative descriptions of operations are explanatorily fundamental. I argue that these debates have erred by conflating the explanatory roles of generalizations and patterns. Patterns are types of variations within or between quantities in a mechanism over time or across conditions. While these patterns must often be represented in addition to descriptions of operations in order to explain a phenomenon, they are not equivalent to generalizations because their explanatory role does not depend on any specific facts about their scope or domain of invariance.

Recently, Estes and Arnold claimed to have “solved” the paradox of evolutionary stasis; they claim that stabilizing selection, and only stabilizing selection, can explain the patterns of evolutionary divergence observed over “all timescales.” While Estes and Arnold clearly think that they have identified the processes that produce evolutionary stasis, they have not. Instead, Estes and Arnold identify a particular evolutionary pattern but not the processes that produce that pattern. This mistake is important; the slippage between pattern and process is common in population and quantitative genetics and contributes to a persistent misunderstanding of the nature of explanations in evolutionary biology.

Kitcher has proposed an ideal-theory account—well-ordered science (WOS)—of the collective good that science’s research agenda should promote. Against criticism regarding WOS’s action guidance, Kitcher has advised critics not to confuse substantive ideals and the ways to arrive at them, and he has defended WOS as a necessary and useful ideal for science policy. I provide a distinction between two types of ideal theories that helps clarifying WOS’s elusive nature. I use this distinction to argue that the action-guidance problem that WOS faces remains even under the aims/means distinction because the WOS’s failure is more basic than critics have suggested.

Additional results are reported on the author's earlier generalization of Richard Jeffrey's solution to the problem of old evidence and new explanation.

In this article I show that population geneticists are acknowledging a kind of biological population that has hitherto been unappreciated by philosophers. The new population talk occurs when population geneticists call continent-level human genetic clusters ‘populations’ in population structure research. My theory is that the kind of population being referred to is the K population, which is, roughly, a biological population whose members are united by common genomic ancestry and in which population membership is graded. After presenting and defending the theory, I show that the K population is indeed a kind of biological population. Finally, I address likely objections.

Biological foundations of the psychoneural identity hypothesis are explicated and their implications discussed. “Consciousness per se” and phenomenal contents of consciousness per se are seen to be identical with events in the (unobserved) brain in accordance with Leibniz's Law, but only informationally equivalent to neural events as observed. Phenomenal content potentially is recoverable by empirical means from observed neural events, but the converse is not possible. Consciousness per se is identical with events which do not represent anything distal to sensory receptor-transducer systems. Thus, on the psychoneural identity hypothesis, consciousness per se comprises directly physical events-in-themselves rather than being a Euclidean representation of physical events as is the case for phenomenal content. After comparing consciousness per se to “onta,” a paradox is suggested: rather than being irreducible to physical reality, consciousness per se is the only experience congruent with the ultimate nature of physical reality as conceived by contemporary physics.

This paper argues that when used judiciously Bayes's law has a role to play in the evaluation of scientific hypotheses. Several examples are presented in which a rational response to evidence requires a judgement whether to apply Bayes's law or whether, for example, to redistribute prior probabilities. The paper concludes that reflection on Bayes's law illustrates how an adequate account of the rational evaluation of hypotheses requires an account of judgement—a point which several philosophers have noted despite few attempts to develop an adequate theory of judgement.

Professor Reichenbach's writings have repeatedly called attention to the important rôle which probability statements play in all inquiry, and he has made amply clear that no philosophy of science can be regarded as adequate which does not square its accounts with the problems of probable inference. Recently he has brought together in convenient form many reflections on the methodology of science familiar to readers of his earlier works, and at the same time he has set himself the task of solving many well-known problems of epistemology in terms of his theory of probability. His latest book is therefore of great interest, both because of the light it throws on Professor Reichenbach's own views and because it reveals the power and limitations of one approach to the problems of science. In particular, while it does not add to the details of his theory of probability worked out elsewhere, the applications Professor Reichenbach now makes of it supply fresh clues for judging its import and adequacy. The object of the present essay, therefore, is to expound a number of his views on probability and epistemology, with a view to examining his conclusions and their relevance to the problems he aims to resolve. The discussion will try to determine whether several features of his present views do not follow from assumptions which he has not sufficiently considered; whether his logical constructions do not create new puzzles; and whether a different starting-point should not be taken if the clarification of scientific concepts and procedures, to which Professor Reichenbach's devotion is as unexcelled as it is well known, is to be successfully conducted.

Michael Ruse has offered an interesting and insightful analysis of function statements in biology. The analysis he gives of statements of the form ‘The function of x in z is to do y‘ is :

1. (i) z does y by using x.

2. (ii) y is an adaptation ([4], p. 91).

The first thing to notice about this formulation is the peculiarity of step (ii). There are many cases in which we would naturally say that x was the adaptation, instead of y; or perhaps we might say that everything asserted in step (i) constituted the adaptation. For example, the function of the duck's webbed feet is to enable it to swim. But we would commonly and naturally say that the adaptation was the webbing, not the swimming. It seems to me that Ruse's insistence on the formulation in (ii) points to the major difficulty of his analysis : and understanding what drives him to this unnatural formulation suggests the way out of those difficulties.

To-day economics is considered the most highly developed discipline among the social sciences. Yet, its explanatory and predictive powers are admitted by all hands to be weak compared to those possessed by the physical sciences. This weakness is still frequently explained by apologetic references to the relatively tender age of economic science. This apparently implies that in the normal course of time economics will grow up and achieve the stature and powers of say, physics. The trouble with this argument is that economics is certainly as old as physics. If it lags behind other disciplines in predictive and explanatory powers, lack of time cannot be the cause.

In this article I explore some statistical difficulties confronting going conceptions of ‘group’ as understood in accounts of group selection. Most such theories require real groups but define the reality of groups in ways that make it impossible to test for their reality. There are alternatives, but they either require or invite a nominalism about groups that many theorists abjure.

Election prediction by means of opinion polling is a rare empirical success story for social science. I examine the details of a prominent case, drawing two lessons of more general interest: (1) Methodology over metaphysics. Traditional metaphysical criteria were not a useful guide to whether successful prediction would be possible; instead, the crucial thing was selecting an effective methodology. (2) Which methodology? Success required sophisticated use of case-specific evidence from opinion polling. The pursuit of explanations via general theory or causal mechanisms, by contrast, turned out to be precisely the wrong path—contrary to much recent philosophy of social science.

Faced with the paradox of undermining futures, Humeans have resigned themselves to accounts of chance that severely conflict with our intuitions. However, such resignation is premature: The problem is Humean Supervenience (HS), not Humeanism. This paper develops a projectivist Humeanism on which chance claims are understood as normative, rather than fact stating. Rationality constraints on the cotenability of norms and factual claims ground a factual-normative worlds semantics that, in addition to solving the Frege-Geach problem, delivers the intuitive set of possibilia for each chance law. Hence, the account does not entail HS, and the paradox does not arise. A confirmation theory is developed, and the Principal Principle is justified.

We identify a species of experiment—Kon-Tiki experiments—used to demonstrate the competence of a cause to produce a certain effect, and we examine their role in the historical sciences. We argue that Kon-Tiki experiments are used to test middle-range theory, to test assumptions within historical narratives, and to open new avenues of inquiry. We show how the results of Kon-Tiki experiments are involved in projective (rather than consequentialist) inferences, and we argue (against Kyle Stanford) that reliance on projective inferences does not provide historical scientists with any special protection against the problem of unconceived alternatives.