It is argued that Niels Bohr ultimately arrived at positivistic and antirealist-flavored statements because of weaknesses in his initial objective of accounting for measurement in physical terms. Bohr's investigative approach faced a dilemma, the choices being (i) conceptual inconsistency or (ii) taking the classical realm as primitive. In either case, Bohr's `Complementarity' does not adequately explain or account for the emergence of a macroscopic, classical domain from a microscopic domain described by quantum mechanics. A diagnosis of the basic problem is offered, and an alternative way forward is indicated.
It is argued that Niels Bohr ultimately arrived at positivistic and antirealist-flavored statements because of weaknesses in his initial objective of accounting for measurement in physical terms. Bohr's investigative approach faced a dilemma, the choices being (i) conceptual inconsistency or (ii) taking the classical realm as primitive. In either case, Bohr's `Complementarity' does not adequately explain or account for the emergence of a macroscopic, classical domain from a microscopic domain described by quantum mechanics. A diagnosis of the basic problem is offered, and an alternative way forward is indicated.
In this paper, I try to explain the philosophical problems that Niels Bohr felt had been exposed by the discovery of the "quantum of action," and by the emergence of the quantum theory that arose in large part as a result of his efforts. I won't have space to make the case adequately here, but my own view is that we have not yet fully digested the message brought to us by Bohr's "Copenhagen Interpretation" of Quantum Mechanics, and I suspect that it will finally prove to be every bit as revolutionary as Bohr thought it was.
‘The new wave mechanics gave rise to the hope that an account of atomic phenomena might be obtained which would not differ essentially from that afforded by the classical theories of electricity and magnetism. Unfortunately, Bohr's statement in the following communication of the principles underlying the description of atomic phenomena gives little, if any, encouragement in this direction.’ This comment is to be found in the brief note prefaced by the editors of the British journal Nature to Niels Bohr's paper ‘The Quantum Postulate and the Recent Development of Atomic Theory’ in the supplement of 14 April 1928. The article in question is the famous paper which first introduced and defined the concept of ‘complementarity’ and outlined the basic points of what was to become known as the Copenhagen interpretation of quantum mechanics. In the paper, Bohr returned to the arguments contained in the paper discussed at the International Congress of Physicists held at Como in September 1927 to mark the centenary of the death of Alessandro Volta and published in the proceedings of the same congress. It was probably his conviction that the new viewpoint adopted in the description of nature fully expressed the theoretical and cognitive content of quantum physics coupled with his enthusiasm at having achieved ‘after many years of struggling in the dark […] the fulfilment of the old hopes’ that induced him to give his work broader and more prestigious circulation.
For Bohr quantum mechanics is complete. It expresses all that can be said about the atomic world, which he regards as a newly discovered and separate ontological component of reality, operating at the Planck scale, and describable only with a separate physics, namely, quantum mechanics. The classical world, in contrast, represents its binary and symbiotic counterpart, which is also ontologically substantive, but operates according to 'classical concepts'. The different physics of each component indicates a different ontology, the classical one is accessible to us, as we are classical objects, where the Planck scale does not apply, while the other is not. The measurement problem cannot therefore be solved through the discovery of hidden variables as these are classical in nature and therefore ineffective in explaining the quantum world. The measurement problem is therefore not due to epistemological limitations but emerges directly from a 'two worlds' dualism. Bohr's Copenhagen interpretation has therefore been erroneously misunderstood as a positivist retreat rather than as a view of reality proposing an ontological structure which is dualistic. l then propose similarities between Bohr and a ‘two worlds’ view of Kant, where noumena is an ontology which is inherently unknowable as it is devoid of a priori agents, much as the quantum world is unknowable as it is devoid of Bohr's classical concepts. However, just as classical concepts in Bohr are crucial in constituting classical reality, a priori intuitions and concepts in Kant are crucial in constituting phenomena, which are real ontological objects and not just appearances. The noumenal and quantum realms are therefore both substantive, but impossible to investigate. The phenomenal and classical worlds are also substantive. They are where objects and therefore meaning condenses. They are therefore open to our investigations.
The objective of this paper is to offer an analysis of several key elements within Niels Bohr’s transcendental interpretation of quantum mechanics. After some stage setting, I will demonstrate that a transcendental perspective on Bohr offers several advantages over alternative interpretations. Specifically, I will argue that some of his most contentious claims become more plausible when viewed through a transcendental lens. However, despite these strengths, Bohr’s approach faces challenges. Following an evaluation of what I consider to be the primary weakness in his framework, the final section of the paper will explore potential avenues for enhancing the viability of the Bohrian project, with a specific focus on the role of phenomenology as a potential solution.
This article explores Bohr's argument, advanced under the heading of 'complementarity,' concerning quantum phenomena and quantum mechanics, and its physical and philosophical implications.In Bohr, the term complementarity designates both a particular concept and an overall interpretation of quantum phenomena and quantum mechanics, in part grounded in this concept.While the argument of this article is primarily philosophical, it will also address, historically, the development and transformations of Bohr's thinking, under the impact of the development of quantum theory and Bohr's confrontation with Einstein, especially their exchange concerning the EPR experiment, proposed by Einstein, Podolsky and Rosen in 1935.Bohr's interpretation was progressively characterized by a more radical epistemology, in its ultimate form, which was developed in the 1930s and with which I shall be especially concerned here, defined by his new concepts of phenomenon and atomicity.According to this epistemology, quantum objects are seen as indescribable and possibly even as inconceivable, and as manifesting their existence only in the effects of their interactions with measuring instruments upon those instruments, effects that define phenomena in Bohr's sense.The absence of causality is an automatic consequence of this epistemology.I shall also consider how probability and statistics work under these epistemological conditions.
I argue here that progress in understanding the lessons of quantum physics has been hindered by the tendency to cast Niels Bohr as a villain. Building on the work of Favrholdt, Faye, and Howard, I present a more accurate view of Bohr's proposal for the "epistemological lesson" of quantum physics. I then argue that several interpretive programs -- often presented as alternatives to Copenhagen -- are, after substantial conceptual work, arriving at a view that is notably similar to Bohr's. Using Maudlin’s formulation of the measurement problem as a foil, I argue that it relies on a notion of wave-function completeness that is inappropriate for a genuinely indeterministic theory, and one that Bohr consistently rejected. On Bohr's view, quantum theory permits concrete agents, situated within specific experimental contexts, to make objective descriptions, while refusing the demand for a single, context-free "description from nowhere".