Marij van Strien | Radboud University Nijmegen (original) (raw)

Papers by Marij van Strien

The idea that all physical phenomena should ultimately be reducible to matter and motion was infl... more The idea that all physical phenomena should ultimately be reducible to matter and motion was influential throughout the nineteenth century, although this ideal was never realized and never without critics. But could the notion of matter itself be understood? A unified conception of matter was lacking in nineteenth century physics. As section 2 shows, physicists used different conceptions of matter, and debated the question of the true nature of matter on the basis of philosophical as well as empirical arguments; it turned out to be very challenging to develop a conception of matter that was consistent with experimental findings as well as philosophically satisfactory. Towards the end of the nineteenth century, physicists increasingly rejected the question of the true nature of matter, arguing that this question was irrelevant for physics or altogether meaningless (section 3). This was sometimes seen as an emancipation of physics from philosophy, and sometimes as a result of philosophical reflection on physics.

Bohm's interpretation of quantum mechanics has generally been received as an attempt to restore t... more Bohm's interpretation of quantum mechanics has generally been received as an attempt to restore the determinism of classical physics. However, although this interpretation, as Bohm initially proposed it in 1952, does indeed have the feature of being deterministic, for Bohm this was never the main point. In fact, in other publications and in correspondence from this period, he argued that the assumption that nature is deterministic is unjustified and should be abandoned. Whereas it has been argued before that Bohm's commitment to determinism was connected to his interest in Marxism, I argue for the opposite: Bohm found resources in Marxist philosophy for developing a nondeterministic notion of causality, which is based on the idea of infinite complexity and an infinite number of levels of nature. From ca. 1954 onwards, Bohm's conception of causality further weakened, as he developed the idea of a dialectical relation between causality and chance.

International Studies in the Philosophy of Science

Bohr's work in quantum mechanics posed a challenge to philosophers of science, who struggled with... more Bohr's work in quantum mechanics posed a challenge to philosophers of science, who struggled with the question of whether and to what degree his theories and methods could be considered rational. This paper focuses on Popper, Feyerabend, Lakatos and Kuhn, all of whom recognized some irrational, dogmatic, paradoxical or even inconsistent features in Bohr's work. Popper, Feyerabend and Lakatos expressed strong criticism of Bohr's approach to quantum physics, while Kuhn argued that such criticism was unlikely to be fruitful: progress in science is generally not made through philosophical reflection. Feyerabend's criticism of Bohr gradually weakened, as he gained a more detailed understanding of the development of Bohr's views on quantum mechanics, and this went together with an increasingly critical view of normative philosophy of science and was instrumental to his conversion to 'anarchism'. This paper aims to show that quantum mechanics played a central role in their debates and disagreements on the rationality of science and the possibility of a normative philosophy of science.

HOPOS: : The Journal of the International Society for the History of Philosophy of Science

The theory of quantum mechanics has often been thought to show an affinity with logical empiricis... more The theory of quantum mechanics has often been thought to show an affinity with logical empiricism: in both, observation plays a central role, and questions about what is unobservable are dismissed. However, there were also strong tensions between the logical empiricism of the Vienna Circle and certain implications drawn from quantum physics. In the 1920s and 1930s, many physicists thought that quantum mechanics revealed a limit to what could be known scientifically, and this opened the door to a wide range of speculations, in which quantum mechanics was connected with free will, organic life, psychology and religion – speculations in which many leading quantum physicists engaged. Members of the Vienna Circle, such as Frank and Schlick, looked at quantum mechanics for a confirmation of their empiricist views, but were at the same time critical about these wider implications drawn from quantum mechanics, which in their eyes were connected with broader mysticist and irrational trends in society. They engaged in particular with the views of Bohr and Jordan, both of whom expressed affinities with logical empiricism while at the same time arguing for claims which proved hard to reconcile with the scientific world conception of the Vienna Circle.

The European Physical Journal H, 2021

Determinism is generally regarded as one of the main characteristics of classical physics, that i... more Determinism is generally regarded as one of the main characteristics of classical physics, that is, the physics of the eighteenth and nineteenth century. However, an inquiry into eighteenth and nineteenth century physics shows that the aim of accounting for all phenomena on the basis of deterministic equations of motion remained far out of reach. Famous statements of universal determinism, such as those of Laplace and Du Bois-Reymond, were made within a specific context and research program, and did not represent a majority view. I argue that in this period, determinism was often an expectation rather than an established result, and that towards the late nineteenth and early twentieth century, it more and more took the form of a heuristic principle: physicists such as Mach, Poincaré and Boltzmann regarded determinism as a feature of scientific research, rather than as a claim about the world. It is only retrospectively that an image was created according to which classical physics was uniformly deterministic.

Ernest Nagel. Between Naturalist Pragmatism and Logical Empiricism

According to Ernest Nagel, determinism is central to the scientific enterprise. Faced with the cl... more According to Ernest Nagel, determinism is central to the scientific enterprise. Faced with the claim that determinism fails in quantum mechanics, Nagel proposed a notion of determinism which does not rely on a fundamental level of description, and can play a role in different scientific disciplines irrespective of their reducibility to physics. Nagel argues that determinism ultimately plays the role of a guiding principle in scientific research. In this way, Nagel argues that determinism has an enduring relevance in all domains of science, from quantum physics to the social sciences.

Studies in History and Philosophy of Modern Physics

When David Bohm published his alternative theory of quantum mechanics in 1952, it was not receive... more When David Bohm published his alternative theory of quantum mechanics in 1952, it was not received well; a recurring criticism was that it formed a reactionary attempt to return to classical physics. In response, Bohm emphasized the progressiveness of his approach, and even turned the accusation of classicality around by arguing that he wanted to move beyond classical elements still inherent in orthodox quantum mechanics. In later years, he moved more and more towards speculative and mystical directions. This paper aims to explain this discrepancy between the ways in which Bohm's work on quantum mechanics has been received and the way in which Bohm himself presented it. I reject the idea that Bohm's early work can be described as mechanist, determinist, and realist, in contrast to his later writings, and argue that there is in fact a strong continuity between his work on quantum mechanics from the early 1950s and his later, more speculative writings. In particular, I argue that Bohm was never strongly committed to determinism and was a realist in some ways but not in others. A closer look at Bohm's philosophical commitments highlights the ways in which his theory of quantum mechanics is non-classical and does not offer a way to avoid all 'quantum weirdness'.

Studies in History and Philososphy of Science

This paper aims to show that the development of Feyerabend’s philosophical ideas in the 1950s and... more This paper aims to show that the development of Feyerabend’s philosophical ideas in the 1950s and 1960s largely took place in the context of debates on quantum mechanics.
In particular, he developed his influential arguments for pluralism in science in discussions with the quantum physicist David Bohm, who had developed an alternative approach to quantum physics which (in Feyerabend’s perception) was met with a dogmatic dismissal by some of the leading quantum physicists. I argue that Feyerabend’s arguments for theoretical pluralism and for challenging established theories were connected to his objections to the dogmatism and conservatism he observed in quantum physics.
However, as Feyerabend gained insight in the physical details and historical complexities which led to the development of quantum mechanics, he gradually became more modest in his criticisms. His writings on quantum mechanics especially engaged with Niels Bohr; initially, he was critical of Bohr’s work in quantum mechanics, but in the late 1960s, he completely withdrew his criticism and even praised Bohr as a model scientist. He became convinced that however puzzling quantum mechanics seemed, it was methodologically unobjectionable – and this was crucial for his move towards ‘anarchism’ in philosophy of science.

Synthese

The development of rigorous foundations of differential calculus in the course of the nineteenth ... more The development of rigorous foundations of differential calculus in the course of the nineteenth century led to concerns among physicists about its applicability in physics. Through this development, differential calculus was made independent of empirical and intuitive notions of continuity, and based instead on strictly mathematical conditions of continuity. However, for Boltzmann and Poincaré, the applicability of mathematics in physics depended on whether there is a basis in physics, intuition or experience for the fundamental axioms of mathematics – and this meant that to determine the status of differential equations in physics, they had to consider whether there was a justification for these mathematical continuity conditions in physics. For this reason, their ideas about continuity and discreteness in nature were entangled with epistemology and philosophy of mathematics. They reached opposite conclusions: Poincaré argued that physicists must work with a continuous representation of nature, and thus with differential equations, while Boltzmann argued that physicists must ultimately take nature to be discrete.

Annals of Science

During the period 1860-1880, a number of physicists and mathematicians, including Maxwell, Stewar... more During the period 1860-1880, a number of physicists and mathematicians, including Maxwell, Stewart, Cournot and Boussinesq, used theories formulated in terms of physics to argue that the mind, the soul or a vital principle could have an impact on the body. This paper shows that what was primarily at stake for these authors was a concern about the irreducibility of life and the mind to physics, and that their theories can be regarded primarily as reactions to the law of conservation of energy, which was used among others by Helmholtz and Du Bois-Reymond as an argument against the possibility of vital and mental causes in physiology. In light of this development, Maxwell, Stewart, Cournot and Boussinesq showed that it was still possible to argue for the irreducibility of life and the mind to physics, through an appeal to instability or indeterminism in physics: if the body is an unstable or physically indeterministic system, an immaterial principle can act through triggering or directing motions in the body, without violating the laws of physics.

In this paper I examine the foundations of Laplace’s famous statement of determinism in 1814, and... more In this paper I examine the foundations of Laplace’s famous statement of determinism in 1814, and argue that rather than derived from his mechanics, this statement is based on general philosophical principles, namely the principle of sufficient reason and the law of continuity. It is usually supposed that Laplace’s statement is based on the fact that each system in classical mechanics has an equation of motion which has a unique solution. But Laplace never proved this result, and in fact he could not have proven it, since it depends on a theorem about uniqueness of solutions to differential equations that was only developed later on. I show that the idea that is at the basis of Laplace’s determinism was in fact widespread in enlightenment France, and is ultimately based on a re-interpretation of Leibnizian metaphysics, specifically the principle of sufficient reason and the law of continuity. Since the law of continuity also lies at the basis of the application of differential calculus in physics, one can say that Laplace’s determinism and the idea that systems in physics can be described by differential equations with unique solutions have a common foundation.

The recent discovery of an indeterministic system in classical mechanics, the Norton dome, has sh... more The recent discovery of an indeterministic system in classical mechanics, the Norton dome, has shown that answering the question whether classical mechanics is deterministic can be a complicated matter. In this paper I show that indeterministic systems similar to the Norton dome were already known in the nineteenth century: I discuss four nineteenth century authors who wrote about such systems, namely Poisson, Duhamel, Boussinesq and Bertrand. However, I argue that their discussion of such systems was very different from the contemporary discussion about the Norton dome, because physicists in the nineteenth century conceived of determinism in essentially different ways: whereas in the contemporary literature on determinism in classical physics, determinism is usually taken to be a property of the equations of physics, in the nineteenth century determinism was primarily taken to be a presupposition of theories in physics, and as such it was not necessarily affected by the possible existence of systems such as the Norton dome.

The reversibility problem (better known as the reversibility objection) is usually taken to be an... more The reversibility problem (better known as the reversibility objection) is usually taken to be an internal problem in the kinetic theory of gases, namely the problem of how to account for the second law of thermodynamics within this theory. Historically, it is seen as an objection that was raised against Boltzmann's kinetic theory of gases, which led Boltzmann to a statistical approach to the kinetic theory, culminating in the development of statistical mechanics. In this paper, I show that in the late nineteenth century, the reversibility problem had a much broader significance—it was widely discussed and certainly not only as an objection to Boltzmann's kinetic theory of gases. In this period, there was a conflict between mechanism and irreversibility in physics which was tied up with central issues in philosophy of science such as materialism, empiricism and the need for mechanistic foundations of physical theories, as well as with concerns about the heat death of the universe. I discuss how this conflict was handled by the major physicists of the period, such as Maxwell, Kelvin, Duhem, Poincaré, Mach and Planck, as well as by a number of lesser-known authors.

Book Reviews by Marij van Strien

Research Projects by Marij van Strien

The historical science studies gained their modern form during the long twentieth century. The ai... more The historical science studies gained their modern form during the long twentieth century. The aim of this workshop is to explore the history of this field of study. The term “modern historical science studies” should be understood as a heuristic concept, which indicates a difference from more traditional forms of history of science. The reason behind the choice of this concept is that modern historical science studies are characterized by an interdisciplinary approach to the historical objects of the sciences, whereas more traditional history of science was mainly written as an experience-based reflection by representatives of the respective scientific disciplines themselves. For example, only from the late nineteenth and especially the twentieth century, social science approaches have played an increasingly important role in the historical reflection on the sciences. The contributions to the workshop focus on practices, the circulation processes of concepts, and individual representatives of different approaches to the history of science. Hereby, also the humanities are considered. Furthermore, a purely ‘western’ focus is to be avoided, and the historical science studies in Eastern Europe is to be equally taken into account.