Niels Bohr's philosophical view of quantum mechanics has been the subject of extensive scholarship for the better part of five decades. Yet Bohr’s writings have remained obscure, as evidenced by the variety of different scholarly interpretations of his work. In this chapter, I review the historiography of Bohr scholarship, arguing that his meaning has remained elusive because his central preoccupations lay not so much with an interpretation of the quantum-mechanical formalism, which many commentators see as the problem of quantum theory, but rather with the epistemological question of how we can acquire empirical knowledge of quantum objects by means of experiment. Bohr’s doctrine of classical concepts, I argue, is therefore best understood as a philosophy of experiment.
Niels Bohr's philosophical view of quantum mechanics has been the subject of extensive scholarship for the better part of five decades. Yet Bohr’s writings have remained obscure, as evidenced by the variety of different scholarly interpretations of his work. In this chapter, I review the historiography of Bohr scholarship, arguing that his meaning has remained elusive because his central preoccupations lay not so much with an interpretation of the quantum-mechanical formalism, which many commentators see as the problem of quantum theory, but rather with the epistemological question of how we can acquire empirical knowledge of quantum objects by means of experiment. Bohr’s doctrine of classical concepts, I argue, is therefore best understood as a philosophy of experiment.
It has often been remarked that Bohr's writings on the interpretation of quantum mechanics make scant reference to the mathematical formalism of quantum theory; and it has not infrequently been suggested that this is another symptom of the general vagueness, obscurity and perhaps even incoherence of Bohr's ideas. Recent years have seen a reappreciation of Bohr, however. In this article we broadly follow this "rehabilitation program". We offer what we think is a simple and coherent reading of Bohr's statements about the interpretation of quantum mechanics, basing ourselves on primary sources and making use of and filling lacunas in|recent secondary literature. We argue that Bohr's views on quantum mechanics are more firmly connected to the structure of the quantum formalism than usually acknowledged, even though Bohr's explicit use of this formalism remains on a rather global and qualitative level. In our reading, Bohr's pronouncements on the meaning of quantum mechanics should first of all be seen as responses to concrete physical problems, rather than as expressions of a preconceived philosophical doctrine. In our final section we attempt a more detailed comparison with the formalism and conclude that Bohr's interpretation is not far removed from present-day non-collapse interpretations of quantum mechanics.
Niels Bohr and Philosophy of Physics: Twenty-First Century Perspectives examines the philosophical views, influences and legacy of the Nobel Prize physicist and philosophical spokesman of the quantum revolution, Niels Bohr. The sixteen contributions in this collection by some of the best contemporary philosophers and physicists writing on Bohr's philosophy today all carefully distinguish his subtle and unique interpretation of quantum mechanics from views often imputed to him under the banner of the “Copenhagen Interpretation.” With respect to philosophical influences on Bohr's outlook, the contributors analyse prominent similarities between his viewpoint and Kantian ways of thinking, the views of the Danish philosopher Harald Høffding, and themes characteristic of American pragmatism. In recognizing the importance of Bohr's epistemological naturalism they examine his defence of the indispensability of classical concepts from a variety of different perspectives. This collection shows us that Bohr's interpretation of quantum mechanics, now nearly a century old, still has the power to shed light on a variety of issues that have arisen only since his lifetime, as well as decoherence theory and other non-collapse interpretations. Balancing historical themes with contemporary discussions, Niels Bohr and the Philosophy of Physics establishes Bohr's on-going contribution to the philosophy of physics and examines his place in the history of philosophy.
Niels Bohr, considered one of the fathers of quantum mechanics, formulated a complex interpretation \nof quantum mechanics that guided his understanding of quantum experiments. The contemporary dispute \nbetween realism and anti-realism, the two main approaches to the interpretation of quantum mechanics, \nis often based on different attitudes towards or even readings of Bohr. We propose that a better \nunderstanding of Bohr’s philosophical thought can contribute to the contemporary reconciliation of \nthese opposing philosophical views and thus to a better understanding of the quantum world. Unfortunately, \nin many contemporary interpretations, Bohr’s philosophical approach to quantum mechanics \nhas been misunderstood, re-interpreted or labelled as ambiguous. This is mostly due to the dispersion \nof Bohr’s complex and unique interpretation through different texts, never united in a single systematically \nconceptualized work. To comprehensively explain Bohr’s philosophical approach and his main \nphilosophical concepts, we consider the many similarities between Bohr’s and Husserl’s philosophical \napproach to science. Husserl developed his philosophical standpoint in a cultural context similar to \nBohr’s and shared Bohr’s objects of philosophical consideration as well as his approach to these objects. \nParallel reading of Bohr’s and Husserl’s texts reveals the closeness between Bohr’s ontological realism— \nepistemological anti-realism standpoint and Husserl’s phenomenological standpoint. This explains \ntheir similar views on the relationship between mathematical language, scientific method and Nature. \nWhile Bohr’s use of the term phenomenon is not equal to Husserl’s, Husserl’s rigorous philosophical \nexplanation of the term helps us to better understand Bohr’s use. Furthermore, the parallel reading \nfacilitates better understanding of one of Bohr’s main philosophical theses, often labelled as ambiguous \nand interpreted in different ways, that it is necessary to use classical concepts to describe quantum phenomena. \nWe claim that the thesis is connected with the advance of epistemological reconsideration of \nscience at the time of Bohr’s writing. Thus, Bohr considers some parts of argumentation as self-evident, \nwhile they are not evident to the contemporary reader. Husserl’s analysis of the relationship between science and the life-world offers a much-needed background for a comprehensive understanding of \nBohr’s thesis. The insight into the similarities between Bohr’s and Husserl’s philosophical approach \nto science and scientific phenomena enables a philosophically rigorous reading of Bohr’s texts; it can \neliminate some of the disagreements between realists and anti-realists and provide a firmer philosophical \nground for a dialog between them.
Niels Bohr and the Philosophy of Physics: Twenty-First-Century Perspectives examines the philosophical views, influences and legacy of the Nobel Prize physicist and philosophical spokesman of the quantum revolution, Niels Bohr. The sixteen contributions in this collection by some of the best contemporary philosophers and physicists writing on Bohr’s philosophy today all carefully distinguish his subtle and unique interpretation of quantum mechanics from views often imputed to him under the banner of the “Copenhagen Interpretation.” With respect to philosophical influences on Bohr’s outlook, the contributors analyse prominent similarities between his viewpoint and Kantian ways of thinking, the views of the Danish philosopher Harald Høffding, and themes characteristic of American pragmatism. In recognizing the importance of Bohr’s epistemological naturalism they examine his defence of the indispensability of classical concepts from a variety of different perspectives. This collection shows us that Bohr’s interpretation of quantum mechanics, now nearly a century old, still has
Niels Bohr was one of the central figures in the emergence of quantum mechanics and a paradigmatic example of a scientist who engaged reflectively with his own practice. For several decades, he was also a leading voice in the philosophical interpretation of the theory. Yet toward the end of the twentieth century his influence declined sharply, and his views came to be widely dismissed as obscure or irrelevant. To evaluate Bohr's contributions, we need to resist the analytic philosopher's urge to separate ontology from action---to treat questions about what there is as detachable from the concrete practices through which physical descriptions are articulated and assessed. That ontology-first stance fits uneasily with Bohr's philosophical sensibility, shaped by a Danish tradition that emphasized reflection on meaning, practice, and responsibility rather than the construction of autonomous metaphysical systems. Seen from this perspective, Bohr's philosophical project comes into focus: his central concern was not the limits of knowledge, but with how our concepts can be extended unambiguously into new domains.
Niels Bohr thought that what quantum mechanics has taught us is not only to understand something new, but also a new meaning of the term “to understand”. Bohr wanted to free himself from ontology by putting emphasis on epistemology; i.e. on certain conditions for observation and description. He believed that the epistemological lesson of quantum mechanics was a crucial one. Basically it has two important aspects. 1. Bohr's philosophy leads to a break with the so-called correspondence theory for truth and meaning. It states that true propositions are descriptions of a world that is independent of our observations; i.e. that on a regular basis one can compare with reality, that is, in compare the two areas against each other. Bohr believed that this did not make sense, since in many situations cannot add meaning to a world that has a sich structure (the thing-in-itself), which in turn can be depicted when observed. 2. All knowledge is attained under certain conditions for description. Bohr thought that the long-lasting criterion for valid knowledge is that can communicate it unambiguously to each other. When Bohr emphasised that we are suspended in language in the sense that all knowledge determines what can say about the world in an understandable way, and not what the world actually is, this must be understood in the sense that only know the world as recognised; i.e., structured on the basis of the conditions for description, to which are, as part of the world, necessarily are subjected to. Bohr's emphasis on conditions for descriptions invalidates the well-known distinction between analytic and synthetic propositions. An important feature of the descriptive use of ordinary language, as well as in classical physics, is that description is based on a dividing line between subject and object. This results in idealism and materialism not being tenable positions. Furthermore, it is such that cannot use the designation of things independently of the designation of time and space. Logical principles are only meaningfully applied in situations relating to our conditions for observation. So based on inspiration from Bohr, Favrholdt developed a more adequate and comprehensive philosophy, where he, among other things, states that all humans possess a fundamental language, underlying all languages. This constitutes a number of concepts – the core – where the correct use is dictated by the structure of the world, which humans learn through sensory perception and action.