It is commonly claimed that the universality of critical phenomena is explained through particular applications of the renormalization group (RG). This article has three aims: to clarify the structure of the explanation of universality, to discuss the physics of such RG explanations, and to examine the extent to which universality is thus explained. The derivation of critical exponents proceeds via a real-space or a field-theoretic approach to the RG. Building on work by Mainwood, this article argues that these approaches ought to be distinguished: while the field-theoretic approach explains universality, the real-space approach fails to provide an adequate explanation.

A model of causation is presented which shares the advantages of Reichenbach's definition in terms of the screening-off relation, but which has the added advantage of distinguishing cause and effect without reference to temporal directionality. This model is defined in terms of the masking relation, which in turn is defined in terms of the equivocation relation of communication theory.

Ecological communities are seldom, if ever, biological individuals. They lack causal boundaries as the populations that constitute communities are not congruent and rarely have persistent functional roles regulating the communities’ higher-level properties. Instead we should represent ecological communities indexically, by identifying ecological communities via the network of weak causal interactions between populations that unfurl from a starting set of populations. This precisification of ecological communities helps identify how community properties remain invariant, and why they have robust characteristics. This respects the diversity and aggregational nature of these complex systems while still vindicating them as units worthy of investigation.

Scientific realists have argued that the truth(likeness) of our theories provides the only explanation for the success of science. I consider alternative explanations proposed by antirealists. I endorse Leplin’s contention that neither van Fraassen’s Darwinist explanation nor Laudan’s methodological explanation provides the sort of explanatory alternative which is called for in this debate. Fine’s suggestion— that the empirical adequacy of our theories already explains their success—is more promising for antirealists. Leplin claims that this putative explanation collapses into realism on one reading and into vacuity on another reading. But his analysis conflates three doctrines into two, and one of the three avoids both realism and vacuity.

The fact that the goals and methods of science, as well as its empirical conclusions, are subject to change, is shown to allow at once for: (a) the objectivity of warrant for knowledge claims; (b) the absence of a priori standards from epistemology; (c) the normative character of epistemology; and (d) the rationality of axiological innovation. In particular, Laudan's attempt to make axiological constraints undercut epistemic realism is confuted.

In this paper we critically review the various attempts that have been made to understand quantum field theory. We focus on Teller's (1990) harmonic oscillator interpretation, and Bohm et al.'s (1987) causal interpretation. The former unabashedly aims to be a purely heuristic account, but we show that it is only interestingly applicable to the free bosonic field. Along the way we suggest alternative models. Bohm's interpretation provides an ontology for the theory—a classical field, with a quantum equation of motion. This too has problems; it is not Lorentz invariant.

This article defends lineage pluralism; the view that biological lineages are not a single, unified type of entity. I analyze aspects of evolutionary theory, phylogenetics, and developmental biology to show that these areas appeal to distinct notions of lineage. I formulate three arguments for lineage pluralism. These arguments undercut the main motivations for lineage monism; the view that biological lineages are a single, unified type of entity. Although this view is rarely made explicit, it is often assumed in philosophy and biology. Hence, this article sheds light on this monistic assumption and shows why lineage pluralism should be adopted instead.

Two strategies for using a model as “null” are distinguished. Null modeling evaluates whether a process is causally responsible for a pattern by testing it against a null model. Baseline modeling measures the relative significance of various processes responsible for a pattern by detecting deviations from a baseline model. When these strategies are conflated, models are illegitimately privileged as accepted until rejected. I illustrate this using the neutral theory of ecology and draw general lessons from this case. First, scientists cannot draw certain conclusions using null modeling. Second, these conclusions follow using baseline modeling, but doing so requires more evidence.

Philosophical defenses of cognitive/evolutionary psychological accounts of racialism claim that classification based on phenotypical features of humans was common historically and is evidence for a species-typical, cognitive mechanism for essentializing. They conclude that social constructionist accounts of racialism must be supplemented by cognitive/evolutionary psychology. This article argues that phenotypical classifications were uncommon historically until such classifications were socially constructed. Moreover, some philosophers equivocate between two different meanings of “racial thinking.” The article concludes that social constructionist accounts are far more robust than psychological accounts for the origins of racialism.

This paper is a defense of “explanatory pluralism” (i.e., the view that some events can be correctly explained in two distinct ways). To defend pluralism, I identify two distinct (but compatible) styles of explanation in paleobiology. The first approach (“actual sequence explanation”) traces out the particular forces that affect each species. The second approach treats the trend as “passive” or “random” diffusion away from a boundary in morphological space. I argue that while these strategies are distinct, some trends are correctly explained in both ways. Further, since neither strategy can be reduced or eliminated from paleobiology, we should accept that both strategies can provide correct explanations for a single trend.

During the past decade there has been a very effective campaign against any explanation of remembering whose basic concept is that of a causally mediating trace. This paper attempts to provide such an explanation by presenting an explicit deductive argument for the existence of the memory trace. The conclusion is shown to follow from reasonable, empirical assumptions of which the most interesting is a spatio-temporal contiguity thesis. Set-theoretic techniques are used to provide a framework of analysis and probabilistic definitions of some causal notions, as that of a causal chain, are presented.

In a recent article [4], Fred I. Dretske has proposed a new analysis of natural laws. Dretske rejects the more or less standard view which says that laws are universal truths with a special function or status in science. As an alternative account, he suggests that laws are expressed by singular statements describing the relationship between universal properties and magnitudes: the statement

(1) It is a law that F's are G's3.

is to be analysed as

(2) F-ness ↦ G-ness.

I shall argue, however, that Dretske's reasons for rejecting the standard account are not conclusive. Moreover, his own proposal seems to be either inadequate or reducible to that version of the standard account which takes laws to be nomically necessary generalizations.

The phenomenon of broken spacetime symmetry in the quantum theory of infinite systems seems to point toward an unorthodox ontology. The standard conception of the physical meaning of these symmetries, as changes in coordinates, conflicts with the apparent physical inequivalence of symmetry-related states. I argue that this apparent conflict is an artifact of a subtle error in the extant account of physical equivalence due to Halvorson and Clifton.

“What might have been is an abstraction Remaining a perpetual possibility Only in the world of speculation.”

T. S. Eliot

Burnt Norton

Some of the concerns which motivate attempts to provide a philosophical reduction of nomological necessity are briefly introduced in I. In II, Hempel's treatment of the paradoxes is contrasted with a position which holds that nomological necessity is a pragmatic dimension of laws of nature, and that this pragmatic dimension is of such a type that it prevents laws of nature from contraposing. Such a position is, however, untenable unless (i) the sense of ‘pragmatics’ at issue is specified, and the possibility of pragmatic differences resulting in differences in confirmation is defended, and (ii) a relevant pragmatic difference between contrapositives is indicated. III attempts to satisfy condition (i) by developing a new sense of pure pragmatics and argues that some remarks by Goodman and Scheffler together with work on the logic of explanation by Dr. Rescher and myself suggest that nomological contrapositives are not pragmatically equivalent (i.e. substitutable salva veritate in the pure pragmatics of an ideal scientific language). If such is the case, condition (ii) is also satisfied.

The line of thought from which contemporary Social Science has come forth was occupied with problems of public policy in a way which has since become very much less prominent in the work of social scientists. The classic figures of social thought —Aristotle, Plato, Adam Smith, Montesquieu, Jeremy Bentham, James and John Stuart Mill, Ricardo, Hobbes and Locke, Burke, Machiavelli and Hegel—were all involved in the consideration of the fundmental problems of policy from the point of view of the man who had to exercise power and to make practical decisions. Even where they themselves lived in remoteness from practical affairs the clarification of the standards for the judgment and guidance of public policy was always close to the centre of their attention. The politician's problems, reduced to fundamentals, were their problems. The problem of maintaining order through the prince's exercise of power was the point of departure of classical political philosophy; it was extended by modern liberalism to the maintenance of liberty in a framework of order. Political philosophy was regarded by those who professed it, as a means of enlightening rulers—and citizens—as to the right ends and the approximate means. The great ancestor of modern empirical social research, Sir William Petty, who regarded his task as the quantitative matter-of-fact description of what existed, viewed his problem as set by the prince's need to safeguard and maximise his power. Early economic theory accepted the same task. Even after mercantalism gave way to liberalism, economic theory was still intended to be a guide to policy.

This paper discusses the Einstein-Podolsky-Rosen paradox from a new point of view. In section II, the arguments by which Einstein, Podolsky and Rosen reach their paradoxical conclusions are presented. They are found to rest on two critical assumptions:

1. (a) that before a measurement is made on a system consisting of two non-interacting but correlated sub-systems, the state of the entire system is exactly represented by:

   

2. (b) that the exact measurement of an observable A in one of the sub-systems is possible.

In section III it is shown that assumption (b) is incorrect. Thus we conclude, as did Bohr, that the results of Einstein, Podolsky and Rosen are not valid.

The arguments of section III are quite distinct from Bohr's, and therefore in Section IV this work is related to that of Bohr.

If we take the state function of quantum mechanics to describe belief states, arguments by Stairs and Friedman-Putnam show that the projection postulate may be justified as a kind of minimal change. But if the state function takes on a physical interpretation, it provides no more than what I call a fortuitous approximation of physical measurement processes, that is, an unsystematic form of approximation which should not be taken to correspond to some one univocal “measurement process” in nature. This fact suggests that the projection postulate does not provide a proper locus for interpretive investigation. Readers will also find section 3's analysis of fortuitous approximations of independent interest and presented without the perils of quantum mechanics.

Some biochemical systems require multiple, well-matched parts in order to function, and the removal of any of the parts eliminates the function. I have previously labeled such systems “irreducibly complex,” and argued that they are stumbling blocks for Darwinian theory. Instead I proposed that they are best explained as the result of deliberate intelligent design. In a recent article Shanks and Joplin analyze and find wanting the use of irreducible complexity as a marker for intelligent design. Their primary counterexample is the Belousov-Zhabotinsky reaction, a self-organizing system in which competing reaction pathways result in a chemical oscillator. In place of irreducible complexity they offer the idea of “redundant complexity,” meaning that biochemical pathways overlap so that a loss of one or even several components can be accommodated without complete loss of function. Here I note that complexity is a quantitative property, so that conclusions we draw will be affected by how well-matched the components of a system are. I also show that not all biochemical systems are redundant. The origin of non-redundant systems requires a different explanation than redundant ones.

This article poses a challenge to Schurz’s proposed metainductive justification of induction. It is argued that Schurz’s argument requires a notion of optimality that can deal with an expanding pool of prediction strategies.

Despite influencing the social sciences since the 1930s, S. S. Stevens' “operationist” philosophy of science has yet to be adequately understood. I reconstruct Stevens' operationism from his early work and assess the influence of various views (logical positivism, behaviorism and the “operational viewpoint” of P. W. Bridgman, among others) on Stevens. Stevens' operationism emerges, on my reconstruction, as a naturalistic methodological directive aimed at agreement, founded in turn on the belief that agreement is constitutive of science, the scientific community, and objectivity. Further, I show that operationism is historically and philosophically independent of the views mentioned above.