Several paleontologists have recently challenged the explanatory adequacy of the modern synthetic theory of evolution. Their position is that, contrary to the prevailing view that evolutionary change is gradual, the fossil record manifests long periods of species stasis (equilibrium) punctuated by periods of rapid species formation. And, they argue, this punctuated equilibria pattern challenges the gradualist, adaptationist and extrapolationist assumptions of the modern synthetic theory of evolution and supports a hierarchical, non-extrapolationist (non-reductionist) view of evolution. In this paper I argue that the challenge rests on an inadequate characterization of the modern synthetic theory and that, even accepting punctuated equilibria and an irreducible evolutionary hierarchy, the modern synthetic theory is adequate to explain evolutionary change at all levels of the hierarchy.

Two partition-theorems are proved for a particular causal decision theory. One is restricted to a certain kind of partition of circumstances, and analyzes the utility of an option in terms of its utilities in conjunction with circumstances in this partition. The other analyzes an option's utility in terms of its utilities conditional on circumstances and is quite unrestricted. While the first form seems more useful for applications, the second form may be of theoretical importance in foundational exercises. Comparisons are made with theorems of Richard Jeffrey, Brad Armendt, and Peter Fishburn.

The conditional probability of h given e is commonly claimed to be equal to the probability that h would have if e were learned. Here I contend that this general claim about conditional probabilities is false. I present a counter-example that involves probabilities of probabilities, a second that involves probabilities of possible future actions, and a third that involves probabilities of indicative conditionals. In addition, I briefly defend these counter-examples against charges that the probabilities they involve are illegitimate.

In his important paper “1953 and All That: A Tale of Two Sciences” (1984), Philip Kitcher defends biological antireductionism, arguing that the division of biology into subfields such as classical and molecular genetics is “not simply … a temporary feature of our science stemming from our cognitive imperfections but [is] the reflection of levels of organization in nature” (p. 371). In a recent discussion of Kitcher's views, Alexander Rosenberg has argued, first, that Kitcher has shown that the reduction of classical to molecular genetics is impossible only because of our intellectual limitations and, second, that this kind of antireductionism supports an instrumentalist approach to biological theory. I argue that both of Rosenberg's claims should be rejected despite the fact that Kitcher misdiagnoses the central reason for the failure of reduction.

Although the theory of Jean Piaget is correctly characterized as genetic epistemology, its nature and scope remain unclear and controversial. An examination of Piaget's Introduction à l'épistémologie génétique indicates that Piaget relies heavily upon a model of comparative anatomy and, consequently, that genetic epistemology is about both the history of science and individual development. This biological model seems to be the basis for Piaget's view that the history of science can be seen as a (Kantian) history of scientific concepts whereas psychogenetic development is a history of these very same concepts on the individual level. Finally, although there are passages indicating a different interpretation of the scope of genetic epistemology, I give several reasons for preferring the more liberal interpretation.

There are a number of reasons for doubting the standard view that scientific theories (understood as sets of connected statements) are the best units for investigating scientific continuity and change (that is, research programs continue as long as groups of scientists accept the central tenets of such theories). Here it is argued that one weakness of this approach is that it cannot be used to demarcate adequately scientific communities or conceptual systems (that is, it fails as a classificatory scheme). Recent alternative proposals by Philip Kitcher and David Hull are assessed in terms of their usefulness in demarcating “Darwinism” and the “Darwinians” in the first decade or so after the publication of The Origin of Species, focusing on the case of Charles Lyell.

This paper challenges some leading views about the conditions under which the ascription of beliefs and desires can make sense of, or provide reasons for, a creature's behavior. I argue that it is unnecessary for behavior to proceed from beliefs and desires according to the principles of logic and decision theory, or even from principles that generally get things right. I also deny that it is necessary for behavior to proceed from principles that, though perhaps subrational, are similar to those that we ourselves use. I then propose some conditions that are considerably weaker, and argue that they fulfill the descriptive and explanatory requirements of intentional ascription.

In his book, The Scientific Image, van Fraassen lucidly draws an alternative to scientific realism, which he calls “Constructive Empiricism”. In this epistemological theory, the concept of observability plays the pivotal role: acceptable theories may be believed only where what they say solely concerns observables. Van Fraassen develops a concept of observability which is, as he admits, vague, relative, science-dependent, and anthropocentric. I draw out unacceptable consequences of each of these aspects of his concept. Also, I argue against his assumption that “empirical adequacy” is the same thing as “saving the phenomena”, according to his sense of the expressions.

As a preliminary to the modern theory of measurement with which this paper is chiefly concerned, it is desirable to review a few of the characteristics and implications of classical physics to illustrate the far reaching changes that have taken place in our conception of nature as the result of the development of quantum mechanics.

This essay explores some of the issues raised as regards the relations of philosophy and sociology of science in the work of Rudolf Carnap and Hans Reichenbach. It argues that Hans Reichenbach's distinction between the contexts of discovery and justification should not be seen as erecting a principled normative/descriptive distinction that demarcates philosophy of science from sociology of science. The essay also raises certain issues about the role of volition, decision, and the limits of epistemological concern in the work of Carnap and Reichenbach and in some recent sociology of science. The relations of philosophy of science to sociology of science are seen to be more deeply rooted and more interesting than the Science Warriors would have us believe.

This paper presents a cognitive account of the process of evaluating scientific data. Our account assumes that when individuals evaluate data, they construct a mental model of a data-interpretation package, in which the data and theoretical interpretations of the data are integrated. We propose that individuals attempt to discount data by seeking alternative explanations for events within the mental model; data-interpretation packages are accepted when the individual cannot find alternative accounts for these events. Our analysis indicates that there are many levels at which data-interpretation packages can be accepted or denied.

The metamathematical theorems of Gödel and Church are frequently applied to the philosophy of mind, typically as rational evidence against mechanism. Using methods of Post and Smullyan, these results are presented as purely mathematical theorems and various such applications are discussed critically. In particular, J. Lucas's use of Gödel's theorem to distinguish between conscious and unconscious beings is refuted, while more generally, attempts to extract philosophy from metamathematics are shown to involve only dramatizations of the constructivity problem in foundations. More specifically, philosophical extrapolations from metamathematics are shown to involve premature extensions of Church's thesis.

In an attempt to avert Laudan's pessimistic induction, Kitcher, Worrall and Psillos introduce a narrower version of scientific realism. According to this version, which can be referred to as “localized realism,” realists need not accept every component in a successful theory. They are supposed only to accept those components that led to the theory's empirical success. Consequently, realists can avoid believing in dubious entities like the caloric and ether. This paper examines and critiques localized realism. It also scrutinizes Psillos's historical study of the caloric theory of heat, which is intended to support localized realism.

Isaac Levi uses C. S. Peirce's fallibilism as a foil for his own “epistemological infallibilism“. I argue that Levi's criticisms of Peirce do not hit their target, and that the two pragmatists agree on the fundamental issues concerning background knowledge, certainty, revision of belief, and the aims of inquiry.

This paper presents a method for investigating counterfactual histories of science. A central notion to our theory of science are “advances” (ideas, data, etc.), which are units passed among scientists and which would be conserved in passing from one possible history to another. Advances are connected to each other by nets of causal influence, and we distinguish strong and weak influences. Around sixty types of advances are grouped into ten classes. As our case study, we examine the beginning of the Old Quantum Theory, using a computer to store and process historical information. We describe four plausible possible histories, along with six other implausible ones.

Many people argue that uncertain science—or controversial policies based on science—can be clarified primarily by greater attention to social/political values influencing the science and by greater attention to the vested interests involved. This paper argues that while such clarification is necessary, it is not a sufficient condition for achieving better science and policy; indeed its importance may be overemphasized. Using a case study involving the current, highly politicized controversy over the shape of dose-response curves for biological effects of ionizing radiation, the paper argues that the conflict could be significantly resolved through specific methodological improvements in the areas of metascience and philosophy of science. These improvements focus on taking account, respectively, of scale, data trimming, aggregation, measurability, and simplicity.

This article offers three contrasting cases of the use of neutrality and drift in molecular evolution. In the first, neutrality is assumed as a simplest case for modeling. In the second and third, concepts of drift and neutrality are developed within the context of population genetics testing and the development and application of the molecular clock.

Game theory is often used to explain behavior. Such explanations often proceed by demonstrating that the behavior in question is a Nash equilibrium. Agents are in Nash equilibrium if each agent’s strategy maximizes her payoff given her opponents’ strategies. Nash equilibriums are fundamentally static, but it is usually assumed that equilibriums will be the outcome of a dynamic process of learning or evolution. This article demonstrates that, even in the most simple setting, this need not be true. In two-strategy games with just a single equilibrium, a family of imitative learning dynamics does not lead to equilibrium.

Recent work on the evolution of signaling systems provides a novel way of thinking about genetic information, where information is passed between genes in a regulatory network. I use examples from evolutionary developmental biology to show how information can be created in these networks and how it can be reused to produce rapid phenotypic change.

No account of the development of contemporary empiricism is adequate which neglects the writings and the influence of Charles Peirce. Although he is not easily pigeon-holed and can not be claimed as the exclusive property of any school or movement, it is appropriate that the hundredth anniversary of his birth should be commemorated at this Congress. For the movement of which it is a manifestation is engaged in a coöperative, intensive cultivation of the methods of the sciences with the help of the most advanced tools of modern logic; and Peirce's intellectual career was also a single-minded devotion to that task. It is fitting, also, that his birth-year be celebrated at Harvard by an international congress. For although he was denied the privilege of teaching at this university, much of his influence was propagated by William James and Josiah Royce, two of its great teachers; and however much he may have suffered from neglect during his life-time, his work surely merits recognition from a movement not confined by national bounds. It is characteristic of the best established sciences that though individuals may pursue researches in them independently of one another, the conclusions reached tend to support each other and to converge toward a common stream of sound beliefs; and such convergence is indeed the sole identifiable warrant for the confidence that some measure of the truth has been attained. It is therefore a happy sign that so many of the central ideas of the present movement have been independently developed on both sides of the Atlantic. One is not minimizing the contributions of the Vienna Circle in pointing out that many of its recent views have been taken for granted for some time by American colleagues, largely because the latter have come to intellectual maturity under the influence of Peirce.