SUMMARY. — The formalisms of quantum mechanics, invented in 1925-26, were very quickly and successfully deployed in solving many problems of atomic and molecular physics. For most physicists these successes expressed the physical meaning of the theory. For a few others, mainly German-speaking physicists closely associated with Niels Bohr, quantum mechanics brought a new definition of knowledge applicable to all exercises of the pure and applied reason. In this paper I describe some of the psychological traits of Bohr and the young men he inspired to extend his epistemological teachings to biology, depth psychology, and other fields remote from the quantum theory of the atom. By calling attention to these traits I aim not to belittle Bohr's thought or its extrapolations, but rather to show how an unsystematic philosophy developed in a particular time and place, and with reference to special problems in atomic physics, could have laid claim to universal validity. I conclude with a parallel between Bohr and his band on the one hand and Newton and his immediate disciples on the other.
SUMMARY. — The formalisms of quantum mechanics, invented in 1925-26, were very quickly and successfully deployed in solving many problems of atomic and molecular physics. For most physicists these successes expressed the physical meaning of the theory. For a few others, mainly German-speaking physicists closely associated with Niels Bohr, quantum mechanics brought a new definition of knowledge applicable to all exercises of the pure and applied reason. In this paper I describe some of the psychological traits of Bohr and the young men he inspired to extend his epistemological teachings to biology, depth psychology, and other fields remote from the quantum theory of the atom. By calling attention to these traits I aim not to belittle Bohr's thought or its extrapolations, but rather to show how an unsystematic philosophy developed in a particular time and place, and with reference to special problems in atomic physics, could have laid claim to universal validity. I conclude with a parallel between Bohr and his band on the one hand and Newton and his immediate disciples on the other.
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.
The Copenhagen Interpretation of quantum mechanics has become the standard way of explaining the physical philosophical meaning of the mathematics of microscopic behavior. It developed from the thought of people who attended the Institute for Theoretical Physics of the University of Copenhagen during the 40 years that Niels Bohr directed it, from 1920 to 1962. Bohr took a large part in developing the Copenhagen Interpretation, he didn't escape all controversy over it (although the quote above is a bit of an exaggeration). Bohr did die before the experimental theoretical developments that have transposed the debate over the appropriateness adequacy of the Copenhagen Interpretation into a new key, he may well have been lucky to have escaped when he did. There is no authoritative codification of CI [the Copenhagen Interpretation], write T Gornitz C. E von Weizsacker of the Max Planck Institute in Starnberg, West Germany in' their formal presentation to the recent Loyola Conference on Mathematical Interpretational Problems in Relativistic Quantum Theory, and under the conditions of its origin there probably could not be one.... All prominent authors of the time who wrote on these questions, like Bohr, [Werner] Heisenberg, [Wolfgang] Pauli, J[ohn] v[on] Neumann on one side, [Albert] Einstein [Erwin] Schrodinger on the other, fell, so we feel, into some stammering when they tried to express their own positions. Nevertheless there is what might be called a Copenhagen attitude. It concentrates on observable phenomena, makes statistics probability central to its understanding, considers quantum mechanics primarily a theory of knowledge or information becomes a kind of physica negativa (analogous to a theologia negativa) in trying not to say too much about things that can't be seen or felt. For example, it doesn't much care whether the orbits of electrons in atoms are real or not and, in fact, tends to regard them as unreal. It appears in most textbooks as the standard way of looking at things.
Abstract Wrestling with quantum concepts could sometimes take a heavy toll. Paul Ehrenfest committed suicide in 1933. Pauli sought help from Carl Jung. Others saw parallels between quantum physics and human psychology. Bohr sought to define the quantum domain, to complete and package it, so that he would be related to the quantum theory as Einstein was to relativity. He believed that he was called to proclaim the gospel of complementarity, extended to the domain of human affairs and which, ‘better than any religion . . . would afford people the guidance they needed’. He was soon grappling with pronouncements made by more excitable members of his flock, as their intrusions into biology and philosophy were quickly condemned. The missionaries of the Copenhagen spirit enjoyed a success that was limited largely to a few philosophically inclined physicists of continental Europe. Neither British nor American theorists had need of it.
Many of the pioneers of quantum mechanics – notably Planck, Einstein, Bohr, de Broglie, Heisenberg, Schrodinger, Born, Jordan, Landé, Wigner, and London – were seriously concerned with philosophical problems. In each case one can ask a question of psychological and historical interest: was it a philosophical penchant which drew the investigator towards a kind of physics research which is linked to philosophy, or was it rather that the conceptual difficulties of fundamental physics pulled him willynilly into the labyrinth of philosophy? I shall not undertake to discuss this question, but shall cite an opinion of Peter Bergmann, which I find congenial: he learned from Einstein that “the theoretical physicist is … a philosopher in workingman's clothes” ([1], q. v.). The problems with which I am preoccupied concern the philosophical implications of quantum mechanics – either epistemological, bearing on the extent, validity, and character of human knowledge; or metaphysical, bearing on the character of reality. Although quantum mechanics is not a system of philosophy, one can wonder whether it is susceptible to coherent incorporation in a philosophical system. I propose to examine the thought of three masters of quantum mechanics – Bohr, Heisenberg, and Schrödinger – not with a critical or historical intention, but in hope of finding some enlightenment concerning the problems posed by contemporary physics. I can say in advance that enlightenment will continue to elude us; nevertheless, the ideas of Bohr, Heisenberg and Schrödinger are rich and evocative for new studies.
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.
On October 24th, 1927, the world's most important physicists met in Brussels for what is known as the fifth edition of the Solvay Conference. The focus of the discussion was the new Quantum Mechanics, to which most of the people present at the meeting had contributed but about which they had contrasting opinions. On the one hand, Niels Bohr and Werner Heisenberg claimed they had provided the new science with a definite structure, not subject to further modifications, while on the other, eminent figures such as Erwin Schrodinger and Albert Einstein believed that the theories put forward by the so called Copenhagen School, of which Bohr and Heisenberg were the most important exponents, were incorrect or at least incomplete.