Evolutionary theorists have encountered difficulty in explaining how altruistic behavior can evolve. I argue that these theorists have made this task more difficult than it needs to be by focusing their efforts on explaining how nature could select for a strong type of altruism that has powerful selection forces working against it. I argue that switching the focus to a weaker type of altruism renders the project of explaining how altruism can evolve significantly less difficult. I offer a model of weak altruism that can avoid many of the difficulties that evolutionary accounts of altruism have traditionally faced.

According to Michael Friedman’s theory of explanation, a law X explains laws Y1, Y2, …, Yn precisely when X unifies the Y’s, where unification is understood in terms of reducing the number of independently acceptable laws. Philip Kitcher criticized Friedman’s theory but did not analyze the concept of independent acceptability. Here we show that Kitcher’s objection can be met by modifying an element in Friedman’s account. In addition, we argue that there are serious objections to the use that Friedman makes of the concept of independent acceptability.

Nearly a half century ago, Thomas Kuhn, Paul Feyerabend, Stephen Toulmin, Norwood Russell Hanson, and others issued a challenge to us philosophers of science to make our field more relevant to actual science. That challenge, over time, has elicited a number of useful responses but very few efforts to situate science within its wider social context when philosophizing about science. The unit of analysis for philosophy of science has tended to remain science-in-a-vacuum. I consider the justifications we offer for this failure, our resources for change, and our prospects if we do change.

Although there has been some discussion in the literature of Bas van Fraassen's modal interpretation of Quantum Mechanics, it has for the most part been concentrated on difficulties that van Fraassen's viewpoint shares with those of some other authors, including Kochen, Dieks, and Healey. van Fraassen's approach has, however, some problems of its own; in this note we want to focus on what seems to us to be one of the most serious of these. The difficulty concerns immediately repeated non-disturbing measurements of the same observable on a single system. As is well known, von Neumann's Projection Postulate guarantees that such measurements will always give the same outcome; likewise, in the approaches of the “modalists” mentioned above, such ‘consilience of repeated measurements’ is in one way or another built into the formalism. By contrast, we shall argue, van Fraassen's modal interpretation neither guarantees this result nor adequately explains why it is unnecessary to do so.

It is with some trepidation that I am raising again this old problem, for it may well be said that nothing new could possibly be written on it. On the other hand it can scarcely be maintained that what has been written has left the problem in a satisfactory state. Moreover, it seems to me that some work which has been done recently on the nature of theoretical physics can be used to dispose of most of the difficulties, and it is partly in the hope of drawing attention to that work and its bearings on psychology that I am writing this paper.

We explicate recent results that shed light on the obscure and troubling problem of renormalization in Quantum Field Theory (QFT). We review how divergent predictions arise in perturbative QFT, and how they are renormalized into finite quantities. Commentators have worried that there is no foundation for renormalization, and hence that QFTs are not logically coherent. We dispute this by describing the physics behind liquid diffusion, in which exactly analogous divergences are found and renormalized. But now we are looking at a problem that is physically and formally well-defined, proving that the problems of renormalization, by themselves, cannot refute QFT.

This article argues that quantum observables can include not just self-adjoint operators but any member of the class of normal operators, including those with nonreal eigenvalues. Concrete experiments, statistics, and symmetries are all expressed in this more general context. However, this more general class of observables also requires a new restriction on sets of operators that can be interpreted as observables at once, called ‘sharp sets’.

The claim that theoretical entities are not real, that they are merely convenient fictions, has been defended and attacked in diverse ways. This paper is concerned with only one defense of the fictionalist thesis and with a certain realist attack on it. The defense in question is that theories which prima facie make reference to theoretical entities can be revised in such a way that no such apparent reference is made by eliminating all occurrences of theoretical expressions. It will be argued here that there is a procedure for revising theories which meets certain minimal criteria of adequacy, contrary to arguments in the literature. Further, it will be argued that the existence of this procedure provides neither sufficient nor necessary support for the fictionalist thesis, that this procedure is not of significance in the dispute between the fictionalist and the realist. Whether or not the theoretical-nontheoretical distinction is viable is another story which will not be told here. It will be assumed for the sake of argument that such a distinction can be drawn.

(1) The probability of some generalizations can be lowered by positive instances.

(2) The change in probability (both degree and direction) can depend on factors other than the new evidence, the statement, and the probability of the statement given the old evidence.

W. V. O. Quine's well-known attack upon the analytic-synthetic distinction is held to affect only one of the two species of analytic statements he distinguishes. In particular it is not directed at and does not affect the so-called logical truths. In this paper the scope of Quine's attack is extended so as to embrace the logical truths as well. It is shown that the unclarifiability of the notion of ‘synonymy’ deprives us not only of “analytic statements that are obtainable from logical truths by the replacement of synonyms with synonyms” but of “logical truths” themselves.

Scientific tradition holds that it is essential to permit individual researchers almost complete freedom in their selection of research projects. As a result, structured research planning has not played a major role in determining the course of the sciences. By “structural research planning” we mean the methodical establishment of goals, and the identification of research routines which apparently accord priority to highest value goals, while minimizing the cost and time of their attainment. With increasing competition for limited fiscal and intellectual resources this kind of planning may become more necessary. Let us cite three specific examples: First, the individual researcher is often faced with the question of how best to spend his time in pursuing a particular line of investigation. He must allocate his personal resources of time and talent to work which appears to hold the promise of highest pay-off. Second, on a larger scale, the competition for resources also raises the question of priority among alternative government-sponsored research projects. Individuals proposing equally alluring projects sometimes seek the same funds; government planners need some sort of objective criteria (hopefully based on a rational strategy) in order to judge the proposals. Furthermore, government planners face the problem of justifying their request for “big science” resources; a planning strategy which defines the use and expected output of the requested resources can help in the design and promotion of their concept. Finally, there is a growing sentiment that at least some research should be directed toward the solution of current and anticipated societal problems, to find means of circumventing or minimizing the impact of potentially dangerous problems of civilization. These needs : the choice of individual research, allocation of national resources among competing projects, and selecting research of societal importance, suggest that structured research planning might be valuable.