One of our more fundamental beliefs is that causal chains are continuous in time: we believe that every influence from the past upon the future runs through the present. I argue that this tenet, given certain data, can force conceptual changes upon us. I attempt to formulate a heuristic for discovery, based as explicitly as possible upon this tenet, and illustrate it by means of several examples, one of which is Mendel's discovery of genes.

I argue that a certain version of physicalism, which is viewed by both its admirers and its detractors as non-reductionist, in fact entails two claims which, though not reductionist in the currently most popular sense of ‘reductionist’, conform to the spirit of reductionism sufficiently closely to compromise its claim to be a comprehensively non-reductionist version of physicalism. Putatively non-reductionist versions of physicalism in general, I suggest, are likely to be non-reductionist only in some senses, but not in others, and hence to disappoint those who wish to be physicalists but still to remain soft and cuddly non-reductionists.

Given the personalist's latitudinarian conception of rationality, what is progress toward wisdom? An answer is in C. I. Lewis's concept of the “congruence” of propositions, propositions so related that the antecedent probability of any one of them will be increased if the remainder can be assumed. This effect can be modelled in the probability calculus with due attention to the temporal sequencing of our learning of contingent propositions without ever becoming certain of them, as Jeffrey proposes. A diachronic bootstrapping effect is obtained for Ockham's razor and premises of arguments about a god's existence. As a theory's probability rises with increased evidence, the probability of our earlier evidence rises too.

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.

I argue that Earman and Norton's familiar “hole argument” raises questions as to whether GTR is a deterministic theory only given a certain assumption about determinism: namely, that to ask whether a theory is deterministic is to ask about the physical situations described by the theory. I think this is a mistake: whether a theory is deterministic is a question about what sentences can be proved within the theory. I show what these sentences look like: for interesting theories, a harmless bit of infinitary logic puts in an appearance.

I respond to H. M. Collins's claim (1985, 1990, 1993) that experimental inquiry cannot be objective because the only criterium experimentalists have for determining whether a technique is “working” is the production of “correct” (i.e., the expected) data. Collins claims that the “experimenters' regress,” the name he gives to this data-technique circle, cannot be broken using the resources of experiment alone. I argue that the data-technique circle, can be broken even though any interpretation of the raw data produced by techniques is theory-dependent. However, it is possible to break this circle by eliminating dependence on even those theoretical presuppositions that are shared by an entire scientific community through the use of multiple independently theory-dependent techniques to produce robust bodies of data. Moreover, I argue, that it is the production of robust bodies of data that convinces experimentalists of the objectivity of their data interpretations.

Hacking argues against van Fraassen's constructive empiricism by appeal to features of microscopic imaging. Hacking relies on both our practices involving imaging instruments and the structure of the images produced by these micropractices. Van Fraassen's reply is formally correct yet fundamentally unsatisfying. I aim to strengthen van Fraassen's reply, but must then extend constructive empiricism, specifically the central notion of “theoretical immersion.” I argue that immersion is more analogous to entering a virtual reality than to learning a language. This metaphor assimilates instrument-based practice as well as theoretical debate and explanation, and can provide an anti-realist view of our micro-practices consonant with constructive empiricism.

Abraham Stone recently has published an argument purporting to show that David Bohm's interpretation of quantum mechanics fails to solve the measurement problem. Stone's analysis is not correct, as he has failed to take account of the conditions under which the theorems he cites are proven. An explicit presentation of a Bohmian measurement illustrates the flaw in his reasoning.