Abstract The vitalism-mechanism controversy was a preoccupation of Niels Bohr’s father, a professor of physiology at the University of Copenhagen, and a frequent topic of discussion at the family residence. While the terms are now archaic, the distinction between a living organism, which must interact with its environment, and a detailed scientific description of that organism, which must treat the system as isolated or isolatable, remains ambiguous. Bohr dealt with fundamental ambiguities in biology in the same way that he dealt with fundamental ambiguities in quantum physics-by analyzing the conditions for observation required for unambiguous description and avoiding appeals to extra-scientific or metaphysical constructs.
Abstract The vitalism-mechanism controversy was a preoccupation of Niels Bohr’s father, a professor of physiology at the University of Copenhagen, and a frequent topic of discussion at the family residence. While the terms are now archaic, the distinction between a living organism, which must interact with its environment, and a detailed scientific description of that organism, which must treat the system as isolated or isolatable, remains ambiguous. Bohr dealt with fundamental ambiguities in biology in the same way that he dealt with fundamental ambiguities in quantum physics-by analyzing the conditions for observation required for unambiguous description and avoiding appeals to extra-scientific or metaphysical constructs.
Abstract In August of 1932, quantum physicist Niels Bohr (1885–1962) delivered to the Second International Congress on Light Therapy meeting in Copenhagen his most extended treatment to that date concerning his reflections on the relevance of the new quantum mechanics for biological questions. Developing this against the backdrop of the “mechanism–vitalism” debate, he sketched out how he envisioned the relations of the new physics with classical issues of function, purpose, and teleology in biology. His address, republished here in its earliest English version, was also given in the context of his ongoing discussions of the relations of physics and biology with the German theoretical quantum physicist Ernst Pascual Jordan (1902–1980). Jordan’s subsequent interpretation of Bohr’s arguments resulted in considerable controversy and a long-term misunderstanding of Bohr’s main points. This contribution gives a detailed summary of this historical discussion and the controversies that surrounded Bohr’s arguments. It also examines Bohr’s final statements on the relations of physics and biology in the period before his death in November of 1962. A closing discussion considers the relevance of Bohr’s insights for contemporary discussions of biological reductionism and the place of the human knower in the scientific process. This is followed by the transcription of the rare 1932 text.
On August 15, 1932 Niels Bohr gave opening address of International Congress on Therapy held in Copenhagen. Bohr's title was Light and Life, and his purpose was to draw attention to epistemological implications for life sciences of fundamental changes that quantum theory had brought to conception of natural law (Bohr 1933). He thought that these changes, which extend to very idea of nature of scientific explanation, were important not only for a full appreciation of new situation brought to physics by quantum theory. According to Bohr, these developments had also created an entirely new background for viewing problems of biology, especially as concerns our views on position of living organisms in realm of natural science. In particular, Bohr proposed that notion of complementarity, which he had first presented 5 years earlier at International Congress of Physics in Como, relevant also for physiological and psychological aspects of life. Bohr began his address by stating what nowadays stigmatized as reductionist credo, namely that subtle character of riddle of life notwithstanding, any scientific explanation of biological phenomena necessarily must consist of reducing description of more complex phenomena to that of simpler ones. But, Bohr continued, discovery of an essential limitation of mechanical description of natural phenomena, as revealed by recent development of atomic theory, has lent new interest to old problem of how far program of reductive biological explanations can be carried. Bohr then presented a brief historical account of rise of quantum theory in connection with study of light, which he thought is perhaps least complex of all physical phenomena. Yet, it turned out that despite its lack of complexity, phenomenon of light cannot be given a coherent mechanical explanation, inasmuch as from viewpoint of classical physical theories, the quantum of action . . . must be considered as an irrational notion. The spatial continuity of light propagation, on one hand, and atomicity of light effects on other hand, must, therefore, be considered as complementary aspects of one reality, in sense that each expresses an important feature of phenomena of light. Those aspects are complementary, because, although they are conceptually irreconcilable from a mechanical point of view, they can never be shown to be in direct, or empirical, contradiction. The reason for this that any closer analysis of either wave aspect or particle aspect of light demands mutually exclusive observational arrangements.
On August 15, 1932 Niels Bohr gave opening address of International Congress on Therapy held in Copenhagen. Bohr's title was Light and Life, and his purpose was to draw attention to epistemological implications for life sciences of fundamental changes that quantum theory had brought to conception of natural law (Bohr 1933). He thought that these changes, which extend to very idea of nature of scientific explanation, were important not only for a full appreciation of new situation brought to physics by quantum theory. According to Bohr, these developments had also created an entirely new background for viewing problems of biology, especially as concerns our views on position of living organisms in realm of natural science. In particular, Bohr proposed that notion of complementarity, which he had first presented 5 years earlier at International Congress of Physics in Como, relevant also for physiological and psychological aspects of life. Bohr began his address by stating what nowadays stigmatized as reductionist credo, namely that subtle character of riddle of life notwithstanding, any scientific explanation of biological phenomena necessarily must consist of reducing description of more complex phenomena to that of simpler ones. But, Bohr continued, discovery of an essential limitation of mechanical description of natural phenomena, as revealed by recent development of atomic theory, has lent new interest to old problem of how far program of reductive biological explanations can be carried. Bohr then presented a brief historical account of rise of quantum theory in connection with study of light, which he thought is perhaps least complex of all physical phenomena. Yet, it turned out that despite its lack of complexity, phenomenon of light cannot be given a coherent mechanical explanation, inasmuch as from viewpoint of classical physical theories, the quantum of action . . . must be considered as an irrational notion. The spatial continuity of light propagation, on one hand, and atomicity of light effects on other hand, must, therefore, be considered as complementary aspects of one reality, in sense that each expresses an important feature of phenomena of light. Those aspects are complementary, because, although they are conceptually irreconcilable from a mechanical point of view, they can never be shown to be in direct, or empirical, contradiction. The reason for this that any closer analysis of either wave aspect or particle aspect of light demands mutually exclusive observational arrangements.
Abstract Niels Bohr was born on 7 October 1885, the son of Professor Christian Bohr, the physiologist, and Ellen, daughter of D. B. Alder, a banker. He had one sister, Jenny, and a brother, Harald, who became Professor of Mathematics in the University of Copenhagen. They grew up in a home of culture. From his father, Niels became acquainted with the problems of biology and in later years became interested again in biological problems through his interests in complementarity. He was educated in Copenhagen, first at the Gammelholm School and then at the University. Whilst there, he became interested in philosophical problems through attending the lectures of Hoffding. According to Rosenfeld (Nordita Publication No. 57) ‘he was fascinated by some of the great religious figures of the past, especially the Jewish prophets and the Buddha; he earnestly endeavoured to penetrate the human side of their teachings and arrived at interpretations of striking originality. Into these sacred texts, coming from the innermost recesses of the human soul, he read an effort to account in a peculiar language for that deepest complementarity between rational knowledge and living experience of the cosmos which in his eyes characterized man’s ambiguous position and rules his whole activity. No wonder that such deep seated views were to play a leading part in his thought in later years and even pervade every shade of his sensitive reaction to the various impressions of everyday life’. During his adolescent years Niels Bohr together with his brother, Harald, were good footballers and his passion for sport was transferred in time to skiing and sailing. He was a lover of the arts and when Eric Gill’s carving of Rutherford installed in the Mond Laboratory at Cambridge was being criticized he was delighted to be presented by Dirac and Kapitza with a copy for his Institute at Copenhagen.
Niels Bohr, the founding father of modern atomic physics and quantum theory, was as original a philosopher as he was a physicist. This study explores several dimensions of Bohr's vision: the formulation of quantum theory and the problems associated with its interpretation, the notions of complementarity and correspondence, the debates with Einstein about objectivity and realism, and his sense of the infinite harmony of nature. The author's chief attention is given to Bohr's epistemological lesson, the conviction that all our description of nature is dependent on the words we use and the ways we can unambiguously use them. Against those who would view Bohr as a vague positivist, the author argues here that Bohr is best understood as using transcendental arguments and shaping a kind of descriptive metaphysics in his defence of our abilities to offer a description of the world we live in.
The views of Niels Bohr on complementarity are examined, both in physics and in other fields. N. Bohr's opinions on the relationship between physics and biology are discussed in detail. It is shown that, over a number of years, Bohr viewed as complementary the study of organisms as atomic-molecular and as integral systems. Subsequently, owing to the development of molecular biology, Bohr rejected the idea of the complementarity in principle of the stated two types of studies. The current status of the physical theory of biological phenomena is examined, and the role of synergetics in this field is noted. The so-called antireductionism is criticized. It is shown that the views of contemporary eminent theoretical biologists reveal them to be unfamiliar with physics. The very important role of physics in the further development of biology and its practical applications is emphasized.