Despite decades of research and thought on the meaning and identification of revolutions in science, there is no generally accepted definition for this concept. This paper presents 13 different characteristics that have been used by philosophers and historians of science to characterize revolutions in science, in general, and in chemistry, in particular. These 13 characteristics were clustered into six independent factors. Suggestions are provided as to the use of these characteristics and factors to evaluate historical events as to their possible (...) categorization as revolutions in chemistry. Challenges to the goal of creating a consensus definition of “revolutions in science” are also presented in this publication. (shrink)

Explanatory contrastivists hold that we often explain phenomena of the form p rather than q. In this paper, I present a new, social‐epistemological model of contrastive explanation—accountabilism. Specifically, my view is inspired by social‐scientific research that treats explanations fundamentally as accounts; that is, communicative actions that restore one's social status when charged with questionable behaviour. After developing this model, I show how accountabilism provides a more comprehensive model of contrastive explanation than the causal models of contrastive explanation that are currently (...) en vogue. (shrink)

Next SectionOne of the indisputable signs of the progress made in organic chemistry over the last two hundred years is the increased ability of chemists to manipulate, control, and design chemical reactions. The technological expertise manifest in contemporary synthetic organic chemistry is, at least in part, due to developments in the theory of organic chemistry. By appealing to a notable chemist's attempts to articulate and codify the heuristics of synthetic design, this paper investigates how understanding theoretical organic chemistry facilitates progress (...) in synthetic organic chemistry. The picture that emerges of how the applications of organic chemistry are grounded in its theory is contrasted with both standard and some more contemporary philosophical accounts of the applications of science. IntroductionTotal Synthesis as Applied ScienceUnderstanding Organic ChemistryThe Heuristics of Synthetic DesignAn Example: LongifoleneConclusion. (shrink)

This article examines a scientific controversy that raged for twenty years in physical organic chemistry during the second half of the twentieth century. After explaining what was at stake in the non-classical ion debate, I attempt—by examining the methodological reflections of some of the participants—a partial explanation of what sustained this controversy, particularly during its early stages. Instead of suggesting a breakdown of scientific method or the unavoidable historical contingency of scientific development, the endurance of this controversy instead reveals the (...) heuristic and pragmatic character of many of the explanations and predictions generated by theoretical organic chemistry. The results in this case are used to suggest a new role for the study of scientific controversies in revealing the economics of scientific inquiry. 1 Introduction2 The Non-classical Ion Debate3 Models for the 2-Norbornyl System4 Soft Theories and Reasoning by Analogy5 Scientific Controversy and the Non-classical Ion Debate6 Conclusion. (shrink)

This article investigates how understanding the theory of organic chemistry facilitates the total synthesis of organic compounds. After locating the philosophical significance of this question within the methodology or epistemology of applied science, I summarize the results of previous work on this issue—roughly that theoretical organic chemistry underwrites a sequence of heuristic policies that help to isolate plausible synthetic routes from the array of possibilities provided by structural or descriptive organic chemistry. While this prior account makes a solid start, it (...) does not capture all of the ways that the theory of organic chemistry contributes to total synthesis. This article aspires to enrich this account by exploring some additional ways that theory contributes. More specifically, I investigate how understanding the theory of organic chemistry can facilitate both the development of novel synthetic reactions and the implementation of a synthetic plan. The role of theory in these aspects of total synthesis will be explored by considering a particular, novel synthesis of longifolene. (shrink)

According to conventional wisdom, local gauge symmetry is not a symmetry of nature, but an artifact of how our theories represent nature. But a study of the so-called theta-vacuum appears to refute this view. The ground state of a quantized non-Abelian Yang-Mills gauge theory is characterized by a real-valued, dimensionless parameter theta—a fundamental new constant of nature. The structure of this vacuum state is often said to arise from a degeneracy of the vacuum of the corresponding classical theory, which degeneracy (...) allegedly arises from the fact that “large” (but not “small”) local gauge transformations connect physically distinct states of zero field energy. If that is right, then some local gauge transformations do generate empirical symmetries. In defending conventional wisdom against this challenge I hope to clarify the meaning of empirical symmetry while deepening our understanding of gauge transformations. I distinguish empirical from theoretical symmetries. Using Galileo’s ship and Faraday’s cube as illustrations, I say when an empirical symmetry is implied by a theoretical symmetry. I explain how the theta-vacuum arises, and how “large” gauge transformations differ from “small” ones. I then present two analogies from elementary quantum mechanics. By applying my analysis of the relation between empirical and theoretical symmetries, I show which analogy faithfully portrays the character of the vacuum state of a classical non-Abelian Yang-Mills gauge theory. The upshot is that “large” as well as “small” gauge transformations are purely formal symmetries of non-Abelian Yang-Mills gauge theories, whether classical or quantized. It is still worth distinguishing between these kinds of symmetries. An analysis of gauge within the constrained-Hamiltonian formalism yields the result that “large” gauge transformations should not be classified as gauge transformations; indeed, nor should “global” gauge transformations. In a theory in which boundary conditions are modeled dynamically, “global” gauge transformations may be associated with physical symmetries, corresponding to translations of these extra dynamical variables. Such translations are symmetries if and only if charge is conserved. But it is hard to argue that these symmetries are empirical, and in any case they do not correspond to any constant phase change in a quantum state. (shrink)