Henk W. de Regt

This article analyses an episode in the earlyhistory of quantum theory: the controversy betweenPauli and Heisenberg about the anomalous Zeemaneffect, which was a main stumbling block for the oldquantum theory of Bohr. It is argued that theindividual philosophical views of both Pauli andHeisenberg directed their attempts to solve theanomaly and decisively influenced the solutions theyproposed. The results of this case study arecompared with the assertions of four theories ofscientific change, namely those of Kuhn, Lakatos,Laudan and Giere.

This paper approaches the scientific realism question from a naturalistic perspective. On the basis of a historical case study of the work of James Clerk Maxwell and Ludwig Boltzmann on the kinetic theory of gases, it shows that scientists’ views about the epistemological status of theories and models typically interact with their scientific results. Subsequently, the implications of this result for the current realism debate are analysed. The case study supports Giere’s moderately realist view of scientific models and theories, based on the notion of similarity, and it highlights the crucial role of model users. The paper concludes with a discussion of Boltzmann’s Bildtheorie, the sophisticated form of realism that he developed in response to the scientific problems of kinetic theory

I argue that scientific explanation has a pragmatic dimension that is epistemically relevant. Philosophers with an objectivist approach to scientific explanation (e.g. Hempel, Trout) hold that the pragmatic aspects of explanation do not have any epistemic import. I argue against this view by focusing on the role of models in scientific explanation. Applying recent accounts of modelling (Cartwright, Morgan and Morrison) to a case-study of nineteenth-century physics, I analyse the pragmatic dimension of the process of model construction. I highlight the crucial roles that conceptual tools, skills, and commitments play in this dimension, and show how they contribute to the epistemic aim of science.

This article examines the role of philosophy in the development of the kinetic theory of gases. Two opposing accounts of this role, by Peter Clark and John Nyhof, are discussed and criticized. Contrary to both accounts, it is argued that philosophical views of scientists can fundamentally influence the results of their scientific work. This claim is supported by a detailed analysis of the philosophical views of Maxwell and Boltzmann, and of their work on the kinetic theory, especially concerning the so-called specific heat anomaly. It leads to the conclusion that the scientific development of the kinetic theory cannot be understood without taking into account the role of philosophy.

Boltzmann’s Bildtheorie, which asserts that scientific theories are ‘mental pictures’ having at best a partial similarity to reality, was a core element of his philosophy of science. The aim of this article is to draw attention to a neglected aspect of it, namely its significance for the issue of scientific explanation and understanding, regarded by Boltzmann as central goals of science. I argue that, in addition to being an epistemological view of the interpretation of scientific theories Boltzmann’s Bildtheorie has implications for the nature of scientific understanding. This aspect has as yet been ignored because discussion of the Bildtheorie has been restricted to the realism-instrumentalism debate. To elucidate my analysis of Boltzmann’s Bildtheorie concrete examples are presented, and the pragmatist and Darwinist roots of Boltzmann’s view are discussed.Moreover, I propose to use Boltzmann’s ideas as a starting-point for developing a novel analysis of the notion of scientific understanding, of which a brief impression is given. It shows that the study of Boltzmann’s philosophy is not only of historical interest but can be relevant also to modern philosophy of science and to the methodology of theoretical physics.

Een van de centrale doelen van wetenschap is het begrijpen van de wereld om ons heen. Wetenschappers geven beschrijvingen van verschijnselen en doen voorspellingen, maar bovenal trachten ze de verschijnselen te verklaren – en wetenschappelijke verklaringen leiden tot begrip. Of het nu het ontstaan van het universum betreft, het gedrag van levende organismen of de huidige sociale en economische ontwikkelingen, wetenschap streeft naar begrip ervan. En niet alleen wetenschappers zelf zijn geïnteresseerd in zulk begrip, wetenschappelijk begrip is van belang voor iedereen. Het Intergovernmental Panel on Climate Change bijvoorbeeld stelt zich expliciet ten doel om te evalueren in hoeverre er wetenschappelijk begrip is van klimaatsverandering. Het begrijpen van de klimaatsverandering is cruciaal voor onze toekomst

Only a decade ago, the topic of scientific understanding remained one that philosophers of science largely avoided. Earlier discussions by Hempel and others had branded scientific understanding a mere subjective state or feeling, one to be studied by psychologists perhaps, but not an important or fruitful focus for philosophers of science. Even as scientific explanation became a central topic in philosophy of science, little attention was given to understanding. Over the last decade, however, this situation has changed. Analyses of scientific understanding that do not treat it as a subjective state or feeling have been offered and debated, and both the epistemic value and the pitfalls of purported psychological ..

In recent years, scientific understanding has become a focus of attention in philosophy of science. Since understanding is typically associated with the pragmatic and psychological dimensions of explanation, shifting the focus from explanation to understanding may induce a shift from accounts that embody normative ideals to accounts that provide accurate descriptions of scientific practice. Not surprisingly, many ‘friends of understanding’ sympathize with a naturalistic approach to the philosophy of science. However, this raises the question of whether the proposed theories of understanding can still have normative power. In this paper I address this question by examining two theories of scientific understanding: Jan Faye’s pragmatic-rhetorical theory and my own contextual theory of scientific understanding. I argue that both theories leave room for normativity, despite their naturalistic tendencies. The normative power of my contextual theory is illustrated with a case study of the chemical revolution.

While the relation between visualization and scientific understanding has been a topic of long-standing discussion, recent developments in physics have pushed the boundaries of this debate to new and still unexplored realms. For it is claimed that, in certain theories of quantum gravity, spacetime ‘disappears’: and this suggests that one may have sensible physical theories in which spacetime is completely absent. This makes the philosophical question whether such theories are intelligible, even more pressing. And if such theories are intelligible, the question then is how they manage to do so. In this paper, we adapt the contextual theory of scientific understanding, developed by one of us, to fit the novel challenges posed by physical theories without spacetime. We construe understanding as a matter of skill rather than just knowledge. The appeal is thus to understanding, rather than explanation, because we will be concerned with the tools that scientists have at their disposal for understanding these theories. Our central thesis is that such physical theories can provide scientific understanding, and that such understanding does not require spacetimes of any sort. Our argument consists of four consecutive steps: We argue, from the general theory of scientific understanding, that although visualization is an oft-used tool for understanding, it is not a necessary condition for it; we criticise certain metaphysical preconceptions which can stand in the way of recognising how intelligibility without spacetime can be had; we catalogue tools for rendering theories without a spacetime intelligible; and we give examples of cases in which understanding is attained without a spacetime, and explain what kind of understanding these examples provide.

While the relation between visualization and scientific understanding has been a topic of long-standing discussion, recent developments in physics have pushed the boundaries of this debate to new and still unexplored realms. For it is claimed that, in certain theories of quantum gravity, spacetime ‘disappears’: and this suggests that one may have sensible physical theories in which spacetime is completely absent. This makes the philosophical question whether such theories are intelligible, even more pressing. And if such theories are intelligible, the question then is how they manage to do so. In this paper, we adapt the contextual theory of scientific understanding, developed by one of us, to fit the novel challenges posed by physical theories without spacetime. We construe understanding as a matter of skill rather than just knowledge. The appeal is thus to understanding, rather than explanation, because we will be concerned with the tools that scientists have at their disposal for understanding these theories. Our central thesis is that such physical theories can provide scientific understanding, and that such understanding does not require spacetimes of any sort. Our argument consists of four consecutive steps: (a) We argue, from the general theory of scientific understanding, that although visualization is an oft-used tool for understanding, it is not a necessary condition for it; (b) we criticise certain metaphysical preconceptions which can stand in the way of recognising how intelligibility without spacetime can be had; (c) we catalogue tools for rendering theories without a spacetime intelligible; and (d) we give examples of cases in which understanding is attained without a spacetime, and explain what kind of understanding these examples provide.

In this paper we have two aims: first, to draw attention to the close connexion between interpretation and scientific understanding; second, to give a detailed account of how theories without a spacetime can be interpreted, and so of how they can be understood. In order to do so, we of course need an account of what is meant by a theory ‘without a spacetime’: which we also provide in this paper. We describe three tools, used by physicists, aimed at constructing interpretations which are adequate for the goal of understanding. We analyse examples from high-energy physics illustrating how physicists use these tools to construct interpretations and thereby attain understanding. The examples are: the ’t Hooft approximation of gauge theories, random matrix models, causal sets, loop quantum gravity, and group field theory.

Achieving understanding of nature is one of the aims of science. In this paper we offer an analysis of the nature of scientific understanding that accords with actual scientific practice and accommodates the historical diversity of conceptions of understanding. Its core idea is a general criterion for the intelligibility of scientific theories that is essentially contextual: which theories conform to this criterion depends on contextual factors, and can change in the course of time. Our analysis provides a general account of how understanding is provided by scientific explanations of diverse types. In this way, it reconciles conflicting views of explanatory understanding, such as the causal-mechanical and the unificationist conceptions.