In Purity and Danger Mary Douglas identifies the concern for purity as a key theme at the heart of every society. In lively and lucid prose she explains its relevance for every reader by revealing its wide-ranging impact on our attitudes to society, values, cosmology and knowledge. The book has been hugely influential in many areas of debate - from religion to social theory. But perhaps its most important role is to offer each reader a new explanation of why people (...) behave in the way they do. With a specially commissioned introduction by the author which assesses the continuing significance of the work thirty-five years on, this Routledge Classics edition will ensure that Purity and Danger continues to challenge and question well into the new millennium. (shrink)

The present paper studies a specific way of addressing the question whether the laws involving the basic constituents of nature are statistical. While most German physicists, above all Planck, treated the issues of determinism and causality within a Kantian framework, the tradition which I call Vienna Indeterminism began from Mach’s reinterpretation of causality as functional dependence. This severed the bond between causality and realism because one could no longer avail oneself of a priori categories as a criterion for empirical reality. (...) Hence, an independent reality criterion had to be sought, a problem which all three physicists to be studied solved in different ways that were mainly conditioned by their different concepts of probability. In order to prevent a dissipation of intuited facts, Mach had to resort to a principle of unique determination as his reality criterion, especially when discussing the Principle of Least Action. Giving theories more independence, Boltzmann understood atomism as property reduction to precisely defined theoretical entities and their interactions. While this served as a relative reality criterion, he also advocated a constructivist one because atomism was already implied by our finitary reasoning power. Finally, Exner contemplated the idea that all apparently deterministic laws are only a macroscopic limit of an irreducible indeterminism, because by adopting the frequency interpretation, observable collectives could be considered as the real basic entities. (shrink)

While the concept of “classical physics” has long framed our understanding of the environment from which modern physics emerged, it has consistently been read back into a period in which the physicists concerned initially considered their work in quite other terms. This essay explores the shifting currency of the rich cultural image of the classical/modern divide by tracing empirically different uses of “classical” within the physics community from the 1890s to 1911. A study of fin‐de‐siècle addresses shows that the earliest (...) general uses of the concept proved controversial. Our present understanding of the term was in large part shaped by its incorporation within the emerging theories of relativity and quantum theory—where the content of “classical” physics was defined by proponents of the new. Studying the diverse ways in which Boltzmann, Larmor, Poincaré, Einstein, Minkowski, and Planck invoked the term “classical” will help clarify the critical relations between physicists’ research programs and their use of worldview arguments in fashioning modern physics. (shrink)

The ArgumentDevelopments in theoretical physics, even when they are revolutionary for physics, usually donotenter public awareness. The reaction to the special relativity theory is one of the few exceptions. The conceptual changes brought by special relativity to our notions of space and time, induced a lively debate not only within intellectual circles but in many strata of the educated middle class. In this article, I focus on a particular moment of public reaction to special and general relativity theory and to (...) its creator Albert Einstein. I try to paint a picture of the anti-Einstein campaign in Germany of 1920, with finer brush strokes than those applied previously by others. My aim is to embed the campaign into the cultural and political climate of the Weimar republic. Without leaving the realm of physics only a superficial understanding of what happened seems possible. My thesis is that the anti-Einstein-campaign was organized, and the physicists involved in it used, mainly in order to rally support for one of the German right-wing parties, the Deutschnationale Volkspartei. (shrink)

Our object in this paper is to study the antecedents, contents, implications, and impact of a not well-known or appreciated paper by EHRENFEST in 1911 on the essential nature of the different quantum hypotheses in radiation theory. After a careful analysis of EHRENFEST’s notebooks, correspondence, and publications, we conclude that the essential points of EHRENFEST’s paper were not perceived to a large extent, and hence that its implications were not considered thoroughly. Specifically, we show that EHRENFEST contributed significantly to the (...) clarifications of the differences between PLANCK’s and EINSTEIN’s respective quantum hypotheses, as well as to those of the concepts ‘‘discontinuity,’’ ‘‘quantization,’’ and ‘‘corpuscularity.’’. (shrink)

According to the standard view, the so-called ‘Copenhagen interpretation’ of quantum mechanics originated in discussions between Bohr and Heisenberg in 1927, and was defended by Bohr in his classic debate with Einstein. Yet recent scholarship has shown Bohr’s views were never widely accepted, let alone properly understood, by his contemporaries, many of whom held divergent views of the ‘Copenhagen orthodoxy’. This paper examines how the ‘myth of the Copenhagen interpretation’ was constructed by situating it in the context of Soviet Marxist (...) critique of quantum mechanics in the 1950s and the response by physicists such as Heisenberg and Rosenfeld. (shrink)

I discuss in detail the contents of the adiabatic hypothesis, formulated by Ehrenfest in 1916. I focus especially on the paper he published in 1916 and 1917 in three different journals. I briefly review its precedents and thoroughly analyze its reception until 1918, including Burgers’s developments and Bohr’s assimilation of them into his own theory. I show that until 1918 the adiabatic hypothesis did not play an important role in the development of quantum theory.

Die Fin de Siècle‐These. Der Aufsatz untersucht das Verhältnis zwischen John Heilbrons Argumentation, die Physiker des ‘fin de siecle’ hätten Bild und Substanz ihrer Disziplin kulturellen Belangen angepasst, und Paul Formans Interpretation der Akausalität in der Weimarer Periode. Ergänzend zu ihrer Fokussierung auf Repräsentationen anstelle von Wahrheit, legten die von Heilbron benannten Anhänger “deskriptionistischer” Epistemologien den Schwerpunkt auf Methodik, statistische anstelle kausaler Erklärungen, historisches Verständnis von Epistemologie und unterstrichen die Beziehungen zwischen der Physik und anderen Disziplinen. Ihre Perspektive liefert einen (...) intellektuellen Kontext – innerhalb der Disziplin Physik – für zumindestens einen Teil dessen, was Forman als Kapitulation vor einer feindlichen sozialen Umgebung, wie sie sich in Oswald Spenglers Der Untergang des Abendlandes ausdrückte, beschrieben hat.The Fin de Siècle Thesis. This paper examines the relations between John Heilbron's argument that fin de siècle physicists adjusted the image and substance of their discipline to cultural concerns, and Paul Forman's approach to acausality in the Weimar period. In addition to their focus on representation rather than truth, adherents of the “descriptionist” epistemologies that Heilbron identified also promoted an emphasis on method, statistical rather than causal explanations, historical understandings of epistemology, and stressed the relations between physics and other disciplines. Their views provide an intellectual context – within the physics discipline – for at least some part of what Forman had described as a capitulation to the hostile social environment expressed in Oswald Spengler's Der Untergang des Abendlandes. (shrink)

This paper takes up the concept of ‘crisis’ at both historical and historiographical levels. It proceeds through two examples of periods that have been described by historians of physics using a language of crisis. The first examines an incipient German theoretical-physics community around 1900 and the debates that concerned the so-called ‘failure’ of the mechanical world view. It is argued, largely on the basis of what is now an extensive body of secondary literature, that there is little evidence for a (...) widespread crisis in this period. Abandoning the term as both description and explanation, one comes to the far more intriguing suggestion that the conflict over foundations was not evidence of a divisive dissonance but rather of collective construction. What has been termed crisis was, in fact, the practice of theoretical physics in the fin de siècle. The second example is the period either side of the advent of quantum mechanics around 1925. Different subgroups within the theoretical-physics community viewed the state of the field in dramatically different ways. Those, such as members of the Sommerfeld school in Munich, who saw the task of the physicist as lying in the solution of particular problems, neither saw a crisis nor acknowledged its resolution. On the other hand those, such as several researchers associated with Niels Bohr's institute in Copenhagen, who focused on the creation and adaptation of new principles, openly advocated a crisis even before decisive anomalies arose. They then sought to conceptualize the development of quantum mechanics in terms of crises and the revolutions that followed. Thomas Kuhn's language of crisis, revolution and anomaly, it is concluded, arises from his focus on only one set of theoretical physicists. A closer look at intra-communal differences opens a new vista onto what he termed ‘normal’ and ‘revolutionary’ science. (shrink)