I argue here that critics of biological explanations of human nature are mistaken when they maintain that the truth of genetic determinism implies the end of critical evaluation and reform of our social institutions. Such a claim erroneously presupposes that our social values, practices, and institutions have nothing to do with what makes biological explanations troublesome. What constitutes a problem for those who are concerned with social justice is not the fact that particular behaviors might be genetically determined, but the fact that our value system and social institutions create the conditions that make such behaviors problematic.

Scientists often study hypotheses that they know to be false. This creates an interpretive problem for Bayesians because the probability assigned to a hypothesis is typically interpreted as the probability that the hypothesis is true. I argue that solving the interpretive problem requires coming up with a new semantics for Bayesian inference. I present and contrast two new semantic frameworks, and I argue that both of them support the claim that there is pervasive pragmatic encroachment on whether a given Bayesian probability assignment is rational.

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 a recent paper Stein (1991) makes a number of criticisms of an earlier paper of mine (Maxwell 1985) that explored the question of whether the idea that the future is genuinely “open” in a probabilistic universe is compatible with special relativity. I disagree with almost all of Stein's criticisms.

It is argued that in his critique of standard nonrelativistic quantum mechanics Einstein formulated three requirements as necessary for a physical theory to be compatible with the field-theorectical paradigm, and it is shown that local, relativistic, algebraic quantum field theory typically satisfies those criteria—although, there are still open questions concerning the status of operational separability of quantum systems localized in spacelike separated space-time regions. It is concluded that local algebraic quantum field theory can be viewed as a research program that Einstein suggested informally in 1948 and that was realized only later in mathematical physics.

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.

T. S. Kuhn's book, The Structure of Scientific Revolutions, [1], is a long and complex work, containing a large number of examples and arguments bearing on questions in the philosophy, history, and sociology of science. My treatment of it here will necessarily be limited, but I will try to state its main theses and discuss them insofar as this can be done without detailed examination of the examples cited from the history of science.

This paper addresses two examples due to Peter Achinstein purporting to show that the positive relevance view of evidence is too strong, that is, that evidence need not raise the probability of what it is evidence for. The first example can work only if it makes a false assumption. The second example fails because what Achinstein claims is evidence is redundant with information we already have. Without these examples Achinstein is left without motivation for his account of evidence, which uses the concept of explanation in addition to that of probability.

A quarter of a century has elapsed since quantum mechanics was discovered. Perhaps it is not too much to say, in retrospect, that the time was ripe for this particular development. This is attested, not only by the speed with which the edifice of the theory was completed immediately following the basic discoveries of Heisenberg and Schrödinger, but also by the rapidity, well-nigh unprecedented in the history of science with which the new results were applied to almost every branch of physics and chemistry. A mental readiness on the part of the scientists involved might have had much more to do with this than the facilities of modern communication systems.

This paper is a discussion of the tenability of methodological solipsism, which typically relies on the so-called Explanatory Thesis. The main arguments in the paper are directed against the latter thesis, according to which internal (or autonomous or narrow) psychological states as opposed to noninternal ones suffice for explanation in psychology. Especially, feedback-based actions are argued to require indispensable reference to noninternal explanantia, often to explanatory common causes. Thus, to the extent that methodological solipsism is taken to require the truth of the Explanatory Thesis, it, too, can be regarded as untenable.

Recent studies have shown that Einstein did not write the EPR paper and that he was disappointed with the outcome. He thought, rightly, that his own argument for the incompleteness of quantum theory was badly presented in the paper. We reconstruct the argument of EPR, indicate the reasons Einstein was dissatisfied with it, and discuss Einstein's own argument. We show that many commentators have been misled by the obscurity of EPR into proposing interpretations of its argument that do not accurately represent Einstein's own views. Finally, we evaluate Einstein's own incompleteness argument, concluding that recent experimental findings have likely shown it to be unsound.

We must start with the cosmos as a going concern and proceed at first analytically. Then we can reverse the process and examine the synthesis. Are there any characters which we must attribute to the cosmos taken as a whole—characters which we must take into account in all the various processes of nature? If so, we shall have a framework for metaphysics or cosmology. Owing to our new interest in nature, metaphysics merges into cosmology. In this respect we are going back to the Greeks, whose interest was cosmic.

The received view in philosophy of biology is that there is a well-understood, philosophically rigorous account of information—causal information. I argue that this view is mistaken. Causal information is fatally undermined by misinterpretations and conflations between distinct independent accounts of information. As a result, philosophical arguments based on causal information are deeply flawed. I end by briefly considering what a correct application of the relevant accounts of information would look like in the biological context.

In this essay I consider whether the theory of organic chemistry is reducible to the theory of quantum chemistry. Using philosophical machinery developed by James Woodward, I characterize the understanding provided by both theories. Then I argue that there are systematic reasons to suspect that quantum chemistry is incapable of supporting some of the significant explanations, predictions, and applications underwritten by an understanding of theoretical organic chemistry. Consequently, even should quantum chemistry be ‘reducible to’ quantum physics in some suitable sense, there are good reasons to doubt that many of the significant results of organic chemistry could be reproduced by quantum chemistry alone.

Recently, Brukner and Zeilinger have presented a number of arguments suggesting that the Shannon information is not well defined as a measure of information in quantum mechanics. If established, this result would be highly significant, as the Shannon information is fundamental to the way we think about information not only in classical but also in quantum information theory. On consideration, however, these arguments are found unsuccessful; I go on to suggest how they might be arising as a consequence of Zeilinger's proposed foundational principle for quantum mechanics.

It is widely acknowledged that the link between quantum language and ordinary language must be “fuzzier” than the traditional eigenstate-eigenvalue link. In the context of spontaneous-collapse theories, Albert and Loewer (1996) argue that the form of this fuzzy link is a matter of convention, and can be freely chosen to minimize anomalies for those theories. I defend the position that the form of the link is empirical, and could be such as to render collapse theories idle. This means that defenders of spontaneous-collapse theories must gamble that the actual form of the link renders such theories tenable.

Rom Harré's proposed Copernican Revolution in the philosophy of science is a very ambitious undertaking. It challenges established views, proposes a radically new model for scientific explanation, and forces a rethinking of the foundations of the field. In his treatment of the natural sciences, Harré rejects all deductivist accounts of scientific explanation (whether these accounts are fashioned by rationalists or empiricists) basically on the grounds that such accounts seriously distort the methods of explanation actually operative in science. In the social sciences Harré, in collaboration with Secord, rejects mechanistic, positivistic, and behavioristic accounts of human behavior [5]. In place of these discarded interpretations he substitutes a new realism which stresses the role that models play in supplying accounts of observed patterns of phenomena in terms of the things and processes whose interactions are responsible for the manifest phenomena. This revolution, if successfully carried out, would indeed be a valuable contribution to the philosophy of science.

Machamer, Darden, and Craver's account of the nature and role of mechanisms in the special sciences has been very influential. Unfortunately, a confusing array of ontic, epistemic, and pragmatic distinctions is required to individuate their mechanisms, mechanism schemata, and mechanism sketches. I diagnose this as a conflation of token-level causal relations with type-level relations. I propose instead that a mechanism is an abstraction that relates entity types and activity types on the model of a directed graph. Mechanisms have an ontic status distinct from the causal chains of token entities and token activities that instantiate them.

The coordination of both logical syntax and methodological analysis of scientific language by scientific empiricism (logical positivism) has achieved a twofold result:

1. Elimination of philosophical pseudo-problems and purification of the empirical sciences from the biases engendered in them by these problems.

2. Creation of an instrument apt for exact formulation, location, and analysis of the real meaning of the valid philosophical issues.

Ever since Berkeley discussed the problem at length in his Essay Toward a New Theory of Vision, theorists of vision have attempted to explain why the moon appears larger on the horizon than it does at the zenith. Prevailing opinion has it that the contemporary perceptual psychologists Kaufman and Rock have finally explained the illusion. This paper argues that Kaufman and Rock have not refuted a Berkeleyan account of the illusion, and have over-interpreted their own experimental results. The moon illusion remains unexplained, and a Berkeleyan account is still a contender.