This contribution argues that Bohr's notion of complementarity can be traced back to the Laozi which he would have read. In Chinese philosophy, polar contrasts such as yin and yang are not regarded as mutually exclusive; they are co-present, existing as a harmonious Whole. Such a conception of metaphysics and logic stood Bohr in good stead for characterising quantum phenomena which are at once both wave and particle. His notion of complementarity bears witness to the possibility of communication and understanding between two different philosophical approaches and scientific traditions—this account adds to Lloyd's concept of semantic stretch.
This contribution argues that Bohr's notion of complementarity can be traced back to the Laozi which he would have read. In Chinese philosophy, polar contrasts such as yin and yang are not regarded as mutually exclusive; they are co-present, existing as a harmonious Whole. Such a conception of metaphysics and logic stood Bohr in good stead for characterising quantum phenomena which are at once both wave and particle. His notion of complementarity bears witness to the possibility of communication and understanding between two different philosophical approaches and scientific traditions—this account adds to Lloyd's concept of semantic stretch.
Recently it has been discovered that Niels Bohr, the father of quantum physics, was acquainted, at a young age, with the ancient Chinese philosophy of Lao-Tzu.New evidence has come to light from a letter written by Bohr himself, discovered in 1998, which is a reply to a letter of inquiry from a Svend Hugo Jiirgensen, a teacher from the Danish town of Aalborg.The teacher had sent Bohr a manuscript entitled 'Tuo Te Ching and the Idea of Complementarity'.Bohr's reply, dated 26 March 1958 begins, "I thank you for your letter and the enclosed little note about Tuo Te Ching, which I have read with great interest.I believe what you say about the old Chinese philosophy is in many ways quite to the point.In my youth I received a beautiful impression of it through Ernst Merller's book 'Oldmester', and at a visit to China twenty years ago I learned how highly the memory of Lao-Tzu is still valued."Since Merller's book was first published in 1909 (the year Bohr turned 24) and Bohr by his own account was in his youth, it is clear that his knowledge of Chinese philosophy preceded his discovery of the complementarity principle in physics ( 1927).While this does not conclusively prove that he learned his idea of complementarity from Chinese philosophy, it is nonetheless a document of great interest.In any event, it is clear that Bohr valued highly ancient Chinese philosophy.It was either instrumental or decisive for his complementarity principle in physics, which has proved invaluable as an explanatory principle for Western physics.What better proof is needed to illustrate that the "Chinese mind" is not "of a different order of humanity" than its accessibility through the medium of Danish language to a Western physicist?That the same Western physicist could then apply the idea of complementarity to understand the workings of the universe common to both Western and Chinese minds is a further demonstration that the Chinese mind is as universal in its application to reality as its Western counterpart.And what better evidence can be cited to show that the
Abstract: Bohr’s interpretation of quantum mechanics has been criticized as incoherent and opportunistic, and based on doubtful philosophical premises. If so Bohr’s influence, in the pre-war period of 1927-1939, is the harder to explain, and the acceptance of his approach to quantum mechanics over de Broglie’s had no reasonable foundation. But Bohr’s interpretation changed little from the time of its first appearance, and stood independent of any philosophical presuppositions. The principle of complementarity is itself best read as a conjecture of unusually wide scope, on the nature and future course of explanations in the sciences (and not only the physical sciences). If it must be judged a failure today, it is not because of any internal inconsistency. Despite the expenditure of much effort, I have been unable to obtain a clear understanding of Bohr’s principle of complementarity (Einstein). Bohr’s point- and the central point of quantum mechanics- is that no elemen-
This paper examines the transformation of Bohr's interpretation of quantum phenomena and quantum mechanics, known as complementarity, from the version presented in his famous Como lecture (1927), which introduced complementarity, to a new version that was developed by Bohr shortly thereafter, in part under the impact of his intervening exchanges with Einstein. While the existence of more than one version of Bohr's complementarity (and of still different versions of the Copenhagen interpretation by others) has been noted, Bohr's rethinking itself of complementarity has rarely been adequately addressed. Apart from refining and indeed correcting the Como argument, the transformation in question was, I argue, defined by a shift from a more philosophical to a more experimental argument. My aim is to explore both this shift and the complexity of the relationships between physics and philosophy in Bohr's thinking in order to understand better the beginnings and the ends, also in the sense of aims, of Bohr's complementarity.
Niels Bohr, as is well known, introduced the notion of complementarity into physics, as a fundamental principle of quantum mechanics. It holds that objects have complementary properties that cannot be measured accurately at the same time. For example, the particle and wave aspects of physical objects are such complementary phenomena. Both concepts are borrowed from classical mechanics, where it is impossible to be both, a particle and a wave at the same time. Particle and Wave represent the complementarity of the Discrete and the Continuous. Humans reason by means of concepts (meanings) and language, as well as, by means of logical or arithmetic symbolism. Meanings are continua, whereas logic and arithmetic are based on relations of identity and difference.
The theory of complementarity became prominent during the last century (primarily as a result of the ideas of Niels Bohr and quantum physics). It gradually developed into a dominant paradigm un-derlying research into the nature of existence. Bohr’s exposition of the principle also emphasized its epistemological value for providing more accurate information regarding what seem to be paradoxical aspects of reality. The principle of complementarity has proven to have far reaching philosophical im-plications concerning such basic notions as subject and object, space-time and causality, chance and necessity, and more. However, scholars also acknowledge that it contributes to resolving the problem of the discontinuity between underlying reality and the human ability to conceptualize the ontological nature of existence. It has grown in popularity because it seems to off er a means of addressing dichoto-mies in other sciences and in philosophy.When analysts scrutinize the factors that infl uenced Bohr’s understanding of the principle of comple-mentarity they fi nd that one source clearly stems from the infl uence of American Pragmatism. Although the Pragmatist infl uence is traced primarily to William James there is at the roots of the philosophy of Pragmatism reference made to concepts that refl ect the principle of complementarity explicating how to gain reliable knowledge concerning the nature of existence. From the very inception of American Prag-matism there was the recognition that Western philosophy faced a problem connected with
Complementarity and Deconstruction: Plotnitsky's Analysis and Beyond Makoto Katsumori Akita University The philosophical thought of the modern physicist Niels Bohr (1885–1962), which revolves around the concept of complementarity, has long been a major subject of historical and philosophical inquiry. Many prior studies of Bohr's complementarity, however, seem to be limited by the fact that they largely proceed within the conceptual frames of the "mainstream" philosophy of science. This being the case, his radical questioning of traditional scientific and philosophical notions—such as the unambiguity of concepts and words—has not been adequately addressed, insofar as these notions are uncritically presupposed by the commentators themselves. In other words, Bohr's thought has often been interpreted under certain tacit premises of scientific rationality that are precisely of the kind targeted by his epistemological critique. In recent years, however, there have emerged new approaches to Bohr's idea of complementarity that place it in different, less conventional, philosophical contexts. Among the most notable of these is Arkady Plotnitsky's endeavor to connect Bohr's complementarity with Jacques Derrida's project of deconstruction. In the present article, based on my recent doctoral dissertation,1 I take up this contribution by Plotnitsky as a suitable point of reference from which to [End Page 435] explore anew Bohr's thought with its radical philosophical implications. After outlining Bohr's complementarity argument and Plotnitsky's reading thereof (in the first and second sections, respectively), I will examine a series of problems that seem to face, or to be left unsolved by, Plotnitsky's account (in the third section). This critical appraisal will finally lead me to sketch a new interpretive approach of my own (in the fourth section), which both extends and delimits the intersections between complementarity and deconstruction. As regards the historical development of Bohr's complementarity, I will largely restrict myself to the period between 1927 and 1950, in which the most crucial of his innovative ideas seem to have been presented. I. Bohr's Idea of Complementarity In his 1927 lecture delivered in Como, Italy, entitled "The Quantum Postulate and the Recent Development of Atomic Theory," Niels Bohr introduced the concept and framework of complementarity as a pivotal idea in his interpretation of quantum theory. From then on, he continually developed the idea of complementarity with regard not only to quantum theory but to other fields of knowledge as well. In what follows, I will first outline his complementarity argument in its "early" period, stretching from 1927 to the mid-thirties,—or, more precisely, until just before his 1935 debate with EPR.2 Bohr starts by noting that "our usual description of physical phenomena is based entirely on the idea that the phenomena concerned may be observed without disturbing them appreciably."3 This notion of physical phenomena as undisturbed by observation underlies all of classical physics and is still maintained in the theory of relativity. However, Bohr continues, a new situation has arisen with the development of quantum theory, specifically with "the so-called quantum postulate, which attributes to any atomic process an essential discontinuity, or rather individuality, completely foreign to the classical theories"; this "individuality" implies that "any observation of atomic phenomena will involve an interaction with the [End Page 436] agency of observation not to be neglected" (PWNB, 1: 53–54.). In more specific terms, any observation aimed at space-time coordination brings about an exchange of momentum and energy with the measuring rods and clocks. It is crucial here that this interaction between the object and the instrument of observation is not simply unavoidable, but "uncontrollable," which represents a "feature of irrationality" brought into the description of nature (PWNB, 1: 68, 91). For insofar as the measuring instruments are to fulfill their purpose, the interaction itself cannot be taken into account, and thus the magnitude of the disturbance always remains unknown. It follows, in Bohr's view, that "an independent reality in the ordinary physical sense can neither be ascribed to the phenomena nor to the agencies of observation...