A superselection rule advanced in the course of a quantum-mechanical treatment of some phenomenon is an assertion to the effect that the superposition principle of quantum mechanics is to be restricted in the application at hand. Superselection accounts of measurement all have in common a decision to represent the indicator states of detectors by eigenspaces of superselection operators named in a superselection rule, on the grounds that the states in question are states of a so-called classical quantity and therefore not subject to quantum interference effects. By this strategy superselectionists of measurement expect to dispense with use of projection postulates in treatments of measurement. I shall argue that superselection accounts of measurement are self-contradictory, and that treatments of infinite systems, if they can avoid the contradiction, are not true superselection accounts.

In this paper, I offer a proof that a disastrous conclusion (namely, that any observation report confirms any hypothesis) may be derived directly from two principles of qualitative confirmation which Carl Hempel called the “Converse Consequence Condition” and the “Entailment Condition.” I then discuss three strategies which a defender of the Converse Consequence Condition may deploy to save this principle.

The two most antagonistic schools in contemporary Western philosophy are Existentialism and Logical Positivism. They have nothing in common but the name of philosophy, and even that they deny each other. There is some kind of discussion going on between even such distant schools as Pragmatism and neo-Thomism; Existentialists and Logical Positivists have nothing but sarcasms for each other. To philosophers familiar only with the Anglo-Saxon scene Existentialism must appear negligible. In the Mediterranean countries, on the other hand, where philosophy is a much more popular pastime, Existentialism has an unparalleled vogue and Logical Positivism is considered a horrible aberration from the naturally speculative course of philosophy. In South America whose philosophical life we are apt to underrate Logical Positivism seems to be known to almost nobody, whereas Existentialism, mostly in its German and anti-religious shape, has become, quite paradoxically, the rallying point of “Liberalism,” liberalism, in Spanish countries, being above all anti-catholicism. Although, ironically enough, both Logical Positivism and modern Existentialism originated in German speaking countries, the split between the two goes vaguely parallel with, and may have found some ready echo in, the different cultural inheritance of the Anglo-Saxon and Latin races. Hence, the subject of this paper would seem far-fetched to those steeped in their own national tradition. There is, however, a growing consciousness of the “one world” function of philosophy, particularly with regard to Eastern and Western philosophy (Northrop, Burtt, Conger, etc.). Would it not be a prerequisite of this more ambitious enterprise to gain a clear conception about the most radical split in our own contemporary Western philosophy, the split between Logical Positivism and Existentialism? This paper is an attempt to establish a perspective permitting a just evaluation of the two philosophies.

Gibbs's phase rule treats mixtures by relating the number of independent variables governing their state to the numbers of phases and independent substances. For the case of a single substance, it provides a criterion of purity. But where more substances are involved, the notion of independent substance is less readily understood. Textbook writers sometimes use algebraic terminology in ways that are suggestive but cannot be taken as literally accurate. I suggest that a mereological interpretation applies to these cases, as it captures more concisely the insights underlying the use of algebraic terminology and illuminates the general notion of substance.

Becoming is interpreted by various sciences. The exact sciences, physics, and chemistry, interpret this universal becoming or change of all things on the model of mathematical equations. In such an equation of quantities or magnitudes, one side always balances the other. We call such a process “circular”. Numbers may be subdivided or contracted, they may change their places or positions, but the sum total of the whole equation remains immutably the same. In this manner mechanics constructs change as a change of positions of unchanging particles in a continuous but divisible space and in a continuous but divisible time. Chemistry constructs qualitative change as a change of unchanging elements in such a fashion that the sum total of the elements involved in such transactions is always completely accounted for. But in the twentieth century becoming entered these closed systems. There are no unchanging atoms now, and no unchanging chemical elements. Both the physical atom and the chemical element, thought immutable before, are now seen to disintegrate, to radiate, to change their character according to their position in the “field” of energy in which they occur.

Quantitative laws are more typical of science than are generalizations involving observational predicates, yet much discussion of scientific inference takes the confirmation of a universal generalization by its instances to be typical and paradigmatic. The important difference is that measurement necessarily involves error. It is argued that because of error laws can no more be refuted by observation than they can be verified by observation. Without much background knowledge, tests of a law mainly provide evidence for the distribution of errors of measurement of the quantities involved. With more background knowledge, the data may contribute either to our knowledge of the error distributions, or to the grounds we have for accepting or rejecting the law. With enough background knowledge, data may verify as well as refute laws.

Russell's book on Leibniz appeared in 1900. That it is important, because of its subject and because of its author, hardly needs to be argued. An examination of it, or of parts of it, after more than half a century is therefore in order. Yet the title I chose indicates only part of my intent. The other part is to examine certain ideas, irrespective of what either Leibniz or Russell thought and of what the latter thought about the thoughts of the former. The title best suited to this part is Individuals, Natures, Relations, and Change. The mixed form of presentation, analytic and quasihistorical, has very great advantages. For the nature of the philosophical enterprise is such that an analyst is lost without some grasp or, at least, some image of “structural history.” The danger is that only very few, if any, are masters of two trades; in this case, logical analysis and historical scholarship. I, for one, make no pretense whatsoever of being a scholar. Naturally, I have read in Leibniz; and I did not skip or take lightly anything in the letters to Arnauld and Clarke; but I have by far not read everything that is available. Reading about Leibniz, aside from Russell, of which I did but little, I found Latta and, particularly, Joseph sometimes helpful. More often, though, I felt that the former's Hegelianism and the latter's Aristotelianism had got between them and their subject.

One does not only talk about the length in inches of this sheet of paper but also about the length of this sheet, about length in inches and about length. A clarification of these and related concepts results from a combination of the theory of the length in a definite unit as a fluent, developed by one of the authors, with the other's concept of 2-place fluents. The length ratio L is defined by pairing a number L (α, β) to any two objects of a certain kind, α, β (in a definite order). L thus may be described as the class of all pairs (α, β), L (α, β) for any objects α, β of the said kind. Length of this sheet and length in inches are specializations of this 2-place fluent.

In this paper I argue three things: (1) that the interactionist view underlying Benacerraf's (1973) challenge to mathematical beliefs renders inexplicable the reliability of most of our beliefs in physics; (2) that examples from mathematical physics suggest that we should view reliability differently; and (3) that abstract mathematical considerations are indispensable to explanations of the reliability of our beliefs.

The book of Bergson (1) underlying the present study appeared in 1896. It is entitled “Matter and Memory” and is a philosophical disquisition into the relation and mutual limitations of organic life and inert matter. Bergson proposes to deal with this very general problem under the special aspect of a theory of the functioning of the human brain and the mechanism of ordinary memory. Such use of the inductive method, which starts from a special problem in order to arrive at results that might be generalized later, might endear him to the exact scientist who has a healthy skepticism toward pure generalities. But let us for a moment remain in the realm of generalities in order to better circumscribe the subject: Few people would agree to an entirely mechanistic interpretation of organic life; hence there should be some point in biology at which the deviations from pure mechanism appear explicitly and in their fulness. For the present we shall adopt an intentionally oversimplified mode of expression. Let us say that mechanistic description is causal and that as our analysis progresses we must eventually arrive at a point where we can no longer trace the causal chains in their entirety. At that point we must replace causal “classical” physics by quantum mechanics and form our pictures of microscopic realities of organic matter in terms of the latter. Some of the pertinent problems have been pointed out by the present writer (4) among others, following earlier suggestions by Niels Bohr (2). Suffice it here to say that certain processes of the atomic scale going on in a complex system such as the organic tissue essentially escape detailed observation that would allow us to determine the continuity of an entirely causal nexus. It is possible to make such observations, but they result in physical destruction of the very coherence of the organic tissue upon which the biological functioning depends. Bohr describes this condition by the term “generalized complementarity.” We cannot enter into a discussion of these problems here; let us adopt deliberately the oversimplified and somewhat vague expression that at some point indeterminacies become significant in the microscopic processes that take place in the organic body. We shall try to limit ourselves in this paper to the simplistic notion of a multiplicity of indeterminate events inserted (in a very crude manner of speaking) into the play of molecular reactions that constitute the functioning of the organism from the viewpoint of the physicist and chemist.

The use of ethnography to understand archaeology is both prevalent and controversial. This paper develops an alternative approach, using ethnography to build and test a general theory of forager behaviors, and their variations in different conditions, one which can then be applied even to prehistoric sites differing from contemporary experience. Human behavioral ecology is chosen as the framework theory, and forager social learning as a case study. The argument is then applied to social learning in the late Pleistocene, and hence to a famous archaeological puzzle: the late Pleistocene acceleration of technical innovation and regional differentiation.

My beliefs during the first stage of my philosophical career were a mixed brew of ingredients taken from the Greek and Christian traditions. My tastes were conservative and even reactionary. I believed in the reality of substance, material and mental; I held that there are universal and necessary connections in nature which can be known. In short, I was a naive objectivist about things and about structures. I was a realist about values too. I believed that there are such traits in nature as good and bad, right and wrong, beauty and ugliness, independently of my preferences. I was convinced further that goodness was a supreme causal agent; that—to paraphrase the familiar quotation—righteousness is power. I believed in God. With Plato (in the Phaedo) I maintained that causality is not only efficient but final too; that nature exhibits both a mechanical and a moral order. And these two propositions were, to my view, but twin aspects of the one proposition that nature will not deceive my expectations.

I consider three explanatory strategies from recent systems biology that are driven by mathematics as much as mechanistic detail. Analysis of differential equations drives the first strategy; topological analysis of network motifs drives the second; mathematical theorems from control engineering drive the third. I also distinguish three abstraction types: aggregations, which simplify by condensing details; generalizations, which simplify by generalizing details; and structurations, which simplify by contextualizing details. Using a common explanandum as a reference point—namely, the robust perfect adaptation of chemotaxis in Escherichia coli—I argue that each strategy targets various abstraction types to different mechanistic details.

This paper discusses several philosophical problems with the use of randomized clinical trials (RCTs) in psychotherapy outcome research. The problems include: the impermanence problem, the identification problem, and idiographic problems. The paper concludes with an assessment of the overall case for and against the use of RCTs in psychotherapy outcome research.

I argue that the pessimistic meta-induction (PMI) seems to point an ontological priority of the relations over the objects of the scientific theories of the kind suggested by French and Ladyman (2003). My strategy will involve a critical examination of epistemic structural realism (ESR) and an historical case-study: the prediction of Zeeman's effect in Lorentz's theory of the electron.

Two initially different arguments for indeterminism are often based either upon the Uncertainty Relations or the statistical interpretation of the wave equation of quantum mechanics. Both arguments ultimately involve three factors: (1) the assumption that elementary entities are enough like classical particles for it to make sense to say they are either determined or indetermined, (2) the fact that no exact measurements are possible of quantities supposed to characterize elementary entities, (3) the pragmatic supposition that determinism is false unless exact predictions are theoretically possible.

If it is legitimate to use (3) to prove indeterminism, then an equally legitimate argument can be based upon (2) which denies (1). Thus, it is doubtful that quantum mechanics supports indeterminism, though it may show that the concepts of ‘determined’ and ‘indetermined’ are inapplicable to the world.

I want to commend the article, “Studies in the Logic of Explanation,” Philosophy of Science, April, 1948, by Hempel and Oppenheim. However, there are two points in the article that have been treated in a manner incompatible with the general attitude taken by the authors and, I believe, they are mistaken in these two rather essential matters. The first concerns the relationship between emergents and prediction. The second concerns the relationship between “evidence” or sense data and law.

I present a game-theoretic way to understand the situation describing Newcomb's Problem (NP) which helps to explain the intuition of both one-boxers and two-boxers. David Lewis has shown that the NP may be modelled as a Prisoner's Dilemma game (PD) in which ‘cooperating’ corresponds to ‘taking one box’. Adopting relevant results from game theory, this means that one should take just one box if the NP is repeated an indefinite number of times, but both boxes if it is a one-shot game. Causal decision theorists thus give the right answer for the one-shot situation, whereas the one-boxers’ solution applies to the indefinitely iterated case. Because Nozick's set-up of the NP is ambiguous between a one-shot and a repeated game, both of these solutions may appear plausible—depending on whether one conceives of the situation as one-off or repeated. If the players’ aim is to maximize their payoffs, the symmetric structure of the PD implies that the two players will behave alike both when the game is one-shot and when it is played repeatedly. Therefore neither the observed outcome of both players selecting the same strategy (in the PD) nor, correspondingly, the predictor's accurate prediction of this outcome (in the NP) is at all surprising. There is no need for a supernatural predictor to explain the NP phenomena.