Grete Hermann was a pupil of mathematical physicist Emmy Noether, follower and co-worker of neo-Kantian philosopher Leonard Nelson, and an important intellectual figure in post-war German social democracy. She is best known for her work on the philosophy of modern physics in the 1930s, some of which emerged from intense discussions with Heisenberg and Weizsäcker in Leipzig. Hermann’s aim was to counter the threat to the Kantian notion of causality coming from quantum mechanics. She also discussed in depth the question (...) of ‘hidden variables’ and provided an extensive analysis of Bohr’s notion of complementarity. This volume includes translations of Hermann’s two most important essays on this topic: one hitherto unpublished and one translated here into English for the first time. It also brings together recent scholarly contributions by historians and philosophers of science, physicists, and philosophers and educators following in Hermann’s steps. Hermann's work places her in the first rank among philosophers who wrote about modern physics in the first half of the last century. Those interested in the many fields to which she contributed will find here a comprehensive discussion of her philosophy of physics that places it in the context of her wider work. (shrink)
I argue that quantum decoherence—understood as a dynamical process entailed by the standard formalism alone—carries us beyond conceptual aspects of non-relativistic quantum mechanics deemed insurmountable by many contributors to the recent quantum gravity and cosmology literature. These aspects include various incarnations of the measurement problem and of the quantum -to-classical puzzle. Not only can such problems be largely bypassed or dissolved without default to a particular interpretation, but theoretical work in relativistic arenas stands to gain substantial physical and philosophical insight (...) by incorporating decoherence phenomena. (shrink)
Prior analyses of Grete Hermann’s 1935 essay on the philosophical foundations of quantum mechanics have taken her central aim to be the recovery of an appropriately Kantian notion of causality from this new indeterministic physics. I argue that if one instead reads this essay as primarily an investigation into the meaning and implications of the relative nature of quantum mechanics—not only for physics, but also for fields as different as ethics—certain dimensions of her work appear with greater clarity. Among these (...) are her particular Kantian interpretation of Bohr’s complementarity and correspondence principles, her unique understanding of the quantum-classical divide, the failure of Kant’s a priori categories of space, time and causality to apply literally—even for obtaining classical natural knowledge, and the splitting of truth. (shrink)
Quantum decoherence is receiving a great deal of attention today not only in theoretical and experimental physics but also in branches of science as diverse as molecular biology, biochemistry, and even neuropsychology. It is no surprise that it is also beginning to appear in various philosophical debates concerning the fundamental structure of the world. The purpose of this article is primarily to acquaint non-specialists with quantum decoherence and clarify related concepts, and secondly to sketch its possible implications – independent of (...) particular interpretations of quantum mechanics – for broader philosophical debates. For example, decoherence shows that any method of parsing nature into levels or parts cannot be in principle but instead derives from our perception of the world as classical, a perception that is itself sustained by the process of decoherence. (shrink)
Recent discussions of structuralist approaches to scientific theories have stemmed primarily from Worrall's, in which he defends a position whose historical roots he attributes to Poincare. In the renewed debate inspired by Worrall, it is thus not uncommon to find Poincare's name associated with various structuralist positions. However, Poincare's structuralism is deeply entwined with both his conventionalism and his idealism, and in this paper we explore the nature of these dependencies. What comes out in the end is not only a (...) clearer picture of Poincare's position regarding structuralism, but also two arguments for versions of epistemic structuralism different in kind from that given by Worrall. (shrink)
Elise Crull claims that by invoking decoherence it is possible to obviate many “fine grained” issues often conflated under the common designation of measurement problem, and to make substantial progresses in the fields of quantum gravity and quantum cosmology, without any early incorporation of a particular interpretation in the quantum formalism. We point out that Crull is mistaken about decoherence and tacitly assumes some kind of interpretation of the quantum formalism.
In this paper, we discuss various aspects of Heisenberg’s thought on hidden variables in the period 1927–1935. We also compare Heisenberg’s approach to others current at the time, specifically that embodied by von Neumann’s impossibility proof, but also views expressed mainly in correspondence by Pauli and by Schroedinger. We shall base ourselves mostly on published and unpublished materials that are known but little-studied, among others Heisenberg’s own draft response to the EPR paper. Our aim will be not only to clarify (...) Heisenberg’s thought on the hidden-variables question, but in part also to clarify how this question was understood more generally at the time. (shrink)
Recently I published an article in this journal entitled “Less interpretation and more decoherence in quantum gravity and inflationary cosmology” :1019–1045, 2015). This article generated responses from three pairs of authors: Vassallo and Esfeld :1533–1536, 2015), Okon and Sudarsky :852–879, 2016) and Fortin and Lombardi. In what follows, I reply to the criticisms raised by these authors.
Jodocus Trutfetter (also Trutvetter) was a philosopher and theologian of the via moderna, at the University of Erfurt, in the late fifteenth and early sixteenth centuries. His main works include a textbook on logic, the Summule totius logice, and another on natural philosophy, the Summa in totam physicen. As a proponent of the via moderna, Trutfetter stressed the importance of taking both ancient and modern authorities into account. In questions concerning universals, categories, and psychology, his views were close to (...) those of John Buridan. On the relationship between theology and philosophy he shared, for the most part, William of Ockham’s position. (shrink)
Advocates of scientic realism typically respond to the challenge of the pessimistic meta-induction by turning to the history of science. The episode most frequently discussed is the shift from Fresnel's wave theory of light to Maxwell's electromagnetism. This particular history is taken to represent one of the hardest problems for the realist, for while it exhibits continuity on the empirical level, it simultaneously represents a dramatic shift in ontology. Thus, various authors have proposed methods for defeating the pessimistic meta-induction based (...) solely on consideration of the Fresnel-Maxwell case. In this paper, I present another case study from physics--Fermi's 1934 theory of beta-decay and the ensuing search for a universal description of weak interactions. I argue that the degree of success of two recent proposals for scientic realism--that of John Worrall (1989, 1994, 2007) and Juha Saatsi (2005)--changes importantly in light of this new case study. (shrink)
The publication of the EPR paper in 1935 prompted Heisenberg to draft a manuscript on the question of the completability of quantum mechanics. We give here the English translation of this manuscript with a brief introduction and bibliography.
The celebrated Dreimännerarbeit by Born, Heisenberg and Jordan contains a matrix-mechanical derivation by Jordan of Planck’s formula for blackbody fluctuations. Jordan appears to have considered this to be one of his finest contributions to quantum theory, but the status of his derivation is puzzling. In our Dreimenschenarbeit, we show how to understand what Jordan was doing in the double context of a Boltzmannian approach to statistical mechanics and of the early ‘statistical interpretation’ of matrix mechanics.
Two recent papers appeared in FOOP disagree regarding the role played by decoherence in quantum physics. On the one hand, Elise Crull considers that decoherence, by itself, solves many conceptual problems in quantum physics, with no need of interpretative considerations. On the other hand, Antonio Vassallo and Michael Esfeld reply by correctly claiming that, although decoherence is a powerful tool to deal with conceptual problems, it does not dispense us from interpreting the formalism. In this brief note we want (...) to contribute to the debate with further considerations from another viewpoint. In this work we show that the discussions "decoherence versus interpretation" revolve around whether the theory of decoherence requires interpretive considerations to solve the measurement problem. In general, those discussions take the theory of decoherence for granted, as if it would not involve any difficulty. Therefore, they commonly focus on the "interpretation" wing: even in the case that the open system decoheres in a given basis, the whole closed system is still in a superposition and, thus, without an adequate interpretation, it cannot be said that the observables defined by that basis behave classically. Here we have focused on the "decoherence" wing: given the conceptual challenges that the theory must face and the alternative approaches to the orthodox view, the understanding of the very phenomenon of decoherence still requires a great deal of interpretive work. (shrink)
In Crull it is argued that, in order to confront outstanding problems in cosmology and quantum gravity, interpretational aspects of quantum theory can by bypassed because decoherence is able to resolve them. As a result, Crull concludes that our focus on conceptual and interpretational issues, while dealing with such matters in Okon and Sudarsky, is avoidable and even pernicious. Here we will defend our position by showing in detail why decoherence does not help in the resolution of foundational (...) questions in quantum mechanics, such as the measurement problem or the emergence of classicality. (shrink)
Grete Hermann’s essay “Die naturphilosophischen Grundlagen der Quantenmechanik” has received much deserved scholarly attention in recent years. In this paper, I follow the lead of Elise Crull who sees in Hermann’s work the general outlines of a neo-Kantian interpretation of quantum theory. In full support of this view, I focus on Hermann’s central claim that limited spatio-temporal, and even analogically causal, representations of events exist within an overall relational structure of entangled quantum mechanical states that defy any unified spatio-temporal (...) description. In my view, Hermann also advances an important transcendental argument that perspectival spatio-temporal representations of nature have their foundations in general relational networks that are not spatio-temporal. The key point is that the adoption of a perspectival system within the general network induces the representation but only for that context. These ideas are consistent with a perspectival subject–object principle in Kant and also with Weyl’s work on Lie groups and their representations. (shrink)
The present article discusses the concept of synderesis in the late medieval universities of Erfurt and Leipzig and the later developments in Wittenberg. The comparison between Bartholomaeus Arnoldi of Usingen in Erfurt and Johannes Peyligk in Leipzig shows that school traditions played an important role in the exposition of synderesis by the late medieval scholastic natural philosophers. However, Jodocus Trutfetter's example warns against overemphasizing the importance of the school traditions and reminds us of the manifold history of medieval discussions (...) on synderesis, which were more or less familiar to many authors of this period. Finally, the diverse references to synderesis in the texts of Martin Luther, Johannes Bernhardi of Feldkirch and Philip Melanchthon reveal no uniform relationship with late medieval discussions but rather indicate various ways of adopting scholastic ideas and transforming them in the context of humanist and reformation thinking. (shrink)
It was because of the early modern system of invention privileges that questions concerning inventorship became a recurrent subject matter of legal dispute. This essay focuses mainly on the details of one such dispute, namely the 1597 case litigated in the Dutch Republic between Jacob Floris van Langren and Jodocus Hondius Sr.. The essay assesses how the law shaped, challenged, and constrained claims to innovation, pushing the argument that it was because of the privilege system that the borders between (...) imitation and novelty became ever more clearly defined. The case study thus illustrates how the law functioned as a technology ordering a complex web of knowledge and status claims. (shrink)
During 2017, churches with their roots in the 16th-century Reformation, will be celebrating the legacy of the Reformation. It affords theologians and churches the opportunity to reflect on the principles of the Reformation and its relevance at the start of the 21st century. This contribution reflects on the question of the necessity of church reformation, based on three texts from different periods in the history of the church. Firstly and primarily, Calvin's 'De necessitate reformandae ecclesiae' of 1543 sheds light on (...) the issues the 16th century reformers were faced with and why they believed the church needed reformation. Calvin had a very clear view on the necessity of church reformation, but that it should also come to some conclusion once the liturgy and doctrine are in order. The question of church reformation is then further discussed in the light of two other texts, one from Jodocus van Lodenstein and Karl Barth. All agree on the necessity of church reformation, but differ in terms of theological and practical implications. The contribution concludes with a few remarks on the modern maxim 'ecclesia semper reformanda'. (shrink)
In 1513 the Fifth Lateran Council determined that the immortality of the rational soul is not true only in theology, but also in philosophy. The determination can be related also to the actual teaching of philosophy. In the university of Erfurt, Bartholomaeus Arnoldi de Usingen and Jodocus Trutfetter wrote expositions on natural philosophy at that time. Usingen's and Trutfetter's expositions of De anima represent a position, which faithfully follows in methodology and aspirations the tradition of the via moderna. Furthermore, (...) they give an interpretation of the relationship between philosophy and theology, which Trutfetter considered consonant with the intentions and the formulations of the Fifth Lateran Council; and finally, Trutfetter even presents a practical application of the Council's recommendations. (shrink)
In this article, I present two virtually unknown sixteenth-century views of human freedom, that is, the views of Bartolomaeus de Usingen and Jodocus Trutfetter on the one hand and John Mair on the other. Their views serve as a natural context and partial background to the more famous debate on human freedom between Martin Luther and Erasmus of Rotterdam from 1524–1526. Usingen and Trutfetter were Luther’s philosophy teachers in Erfurt. In a passage from Book III of John Mair’s commentary (...) on Aristotle’s Nicomachean Ethics from 1530, he seems to defend a view of human freedom by which we can will evil for the sake of evil. Very few thinkers in the history of philosophy have defended such a view. The most famous medieval thinker to do so is William Ockham. To illustrate how radical this view is, I place him in the historical context of such thinkers as Plato, Augustine, Buridan, and Descartes. (shrink)
In his Questions on Aristotle’s De anima, John Buridan faced the problem, whether it follows from the definition of the term ‘animal’ that all quantitative parts of an animal are to be called animals. His solution was that parts of the animal are to be called animals, though in a extraordinary, non-connotative, sense of the term. The problem variously discussed by some later Buridanian authors from Erfurt. Bartholomaeus Arnoldi de Usingen ends up to deny the use of such terms as (...) ‘animal’ and ‘human being’ as connotative terms. Jodocus Trutfetter, however, uses the distinction between the absolute and connotative senses of these terms without reservation. (shrink)
In the late fifteenth and early sixteenth centuries the University of Erfurt was one of the strongholds of the via moderna in Germany. The present article examines how this school's identity was manifested in discussions on the soul and its powers, engaged in by three Erfurtian philosophers: Johannes Carnificis de Lutrea, Jodocus Trutfetter and Bartholomaeus Arnoldi de Usingen. In the various forms of their expositions these authors reveal a rather uniform stance concerning doctrinal issues. Their positions are largely based (...) on the tradition of the via moderna going back to the early fifteenth century, and their argumentation is deeply bound to the problems arising from this school's position. Comparisons with concurrent Thomist and Scotist sources show that the Erfurtians describe the positions of other schools in an appropriate manner, although the arguments for and against these positions are often borrowed from the authorities of their own school rather than from contemporaneous discussion. (shrink)
Bartholomaeus Arnoldi (b. c. 1465, d. September 9, 1532) (also called Usingen after his birthplace), began as a philosopher in the via moderna school and later became a member and a theologian of the Order of Augustinian Hermits. Together with Jodocus Trutfetter, he was the most prominent philosopher in Erfurt in the early sixteenth century. Usingen’s main authorities were John Buridan, William of Ockham, Gregory of Rimini, Peter of Ailly, and Gabriel Biel. The focus of his teaching was on (...) a “common view of the via moderna,” which was strongly involved in semantic–metaphysical questions. Usingen stressed the importance of logic as a necessary tool for gaining scientific knowledge, but it was his works on natural philosophy, in particular, that were respected by his contemporaries. In natural philosophy, he generally followed the tradition of Buridan. His discussion on the theory of supposition follows Ockham. On the relationship between theology and philosophy, he strongly posited the unity of truth by allowing certain theological truths a sufficient degree of plausibility as truths in natural philosophy. This view was partly based on Lawrence of Lindores. (shrink)
The Buridanian view of the concrete cognition as the general characteristics of sense perception was adopted by Jodocus Trutfetter and Bartholomaeus Arnoldi of Usingen. This theory was not accepted merely on the basis of authority, but it was argued against the competing view, which appeared as legitimate inside the late medieval school of via moderna.