One can often meet recent writings in different electronic media, which raise claims either that the world we inhabit is a virtual reality or that the universe is unreal, that what we usually understand by the word “reality” is only seeming. In comparison with such claims, Werner Heisenberg’s view about reality, although somehow similar to them, has a philosophical basis that conceptually exceeds them. This philosophical basis, however, encapsulates an epistemological thesis that when man investigates nature, he meets himself as a result. This thesis leads to a curious consequence. The aim of the paper is to present and critically analyze Heisenberg’s view about reality.
One can often meet recent writings in different electronic media, which raise claims either that the world we inhabit is a virtual reality or that the universe is unreal, that what we usually understand by the word “reality” is only seeming. In comparison with such claims, Werner Heisenberg’s view about reality, although somehow similar to them, has a philosophical basis that conceptually exceeds them. This philosophical basis, however, encapsulates an epistemological thesis that when man investigates nature, he meets himself as a result. This thesis leads to a curious consequence. The aim of the paper is to present and critically analyze Heisenberg’s view about reality.
In this chapter, I offer some personal reflections about the nature of reality, shaped by my work as a quantum physicist, my experimentation with psychedelic drugs during the 1960s, and my more recent studies of modern cognitive science. Traditionally, questions about the essential nature of reality are asked by philosophers. In the twentieth century, these questions were asked for the first time by scientists as well. During the first three decades of the century, the exploration of the atomic and subatomic world brought physicists in contact with a strange and unexpected reality that shattered the foundations of their worldview and forced them to think in entirely new ways. Quantum physics showed scientists “a new reality,” and from that time on, the nature of reality became a popular subject of discussion not only in philosophy but also in science. In recent decades, cognitive scientists took another radical step in the scientific conception of the nature of reality. They asserted that the features of our ordinary, everyday reality are not features of an independently existing world, but are created in the very process of perception. In a way this generalizes the influence of the act of perception on the perceived object, which was famously analyzed in quantum physics by Werner Heisenberg, to everyday perception. In other words, even our everyday reality is just one of many alternate realities.
Far from regarding physical science as a universal model of human knowledge, Werner Heisenberg relativized the scientificity of natural science, situating this domain of knowledge in a wide range of our modes of experiencing the world. In this paper, with a focus on his critical analysis of the notion of objectivity in quantum theory and other fields, I survey Heisenberg’s view of the world as divided into six distinct areas of reality, including – but not centered on – physical science. I also seek to show how this conception of the structure of reality, specifically of the relation between different areas of reality, is mediated by his mis- or reinterpretation of Bohr’s idea of complementarity.
The ideas in Heisenberg's paper on quantum mechanics in 1925 mark the beginning not only of a new phase in modern physics, but also of Heisenberg's own philosophical journey. This thesis examines that journey between 1925 and the late 1950s by situating Heisenberg's philosophy of quantum mechanics in the context of his encounters with his contemporaries as well as the context of various strands of thought in the German-speaking world at the time. Heisenberg's early philosophical critique of the 'classical' viewpoint between 1925 and 1927 bears the decisive influence of Einstein's theory of relativity, more specifically, the positivism he saw as underpinning Einstein's emancipation from Newtonian physics. The positivist influence on Heisenberg's early attitude to quantum mechanics is evident in three ways: (a) his invocation of an observability principle in 1925 to justify the renunciation of the concept of the electron orbit, (b) an instrumentalist conception of understanding, which characterised Heisenberg's response to Schrodinger's demand for classical visualisation in space and time in 1926-7, and (c) the introduction of an operational definition of concepts such as position and velocity in 1927, in an attempt to replace the concepts of classical physics. But after discussions with Bohr and Einstein in 1926-7, Heisenberg soon recognised what we might term his `empiricist' viewpoint was problematic. In 1927 Heisenberg's thought undergoes a shift away from the `empiricist' viewpoint that had underpinned his early philosophy of quantum mechanics. The nature and scope of this transformation, which forms the central theme in this thesis, has, up until now, been poorly understood and often completely neglected. Through his discussions with Bohr, Heisenberg came to the realisation that despite their limitations, classical concepts were conditions for the possibility of the description of all experience. This marked the abandonment of his earlier attempt to replace classical concepts with quantum concepts. The recognition of the primacy of classical language forms the point of departure for much of Heisenberg's later thought, which brought him into contact with the attempts in the German-speaking world in the 1920s to reconstruct Kantian epistemology. By the mid-1930s, Heisenberg advocated a 'pragmatic transformation' of Kantian philosophy, in which classical concepts were held to be a priori in the sense that they remained the conditions for the possibility of experience, but were no longer held to be necessary or universal in a strict Kantian sense. After 1940 Heisenberg saw the paradoxes of quantum mechanics under the aegis of what can be termed a 'transcendental conception of language', according to which language is not a mere tool, but actively shapes, gives form, and objectifies, our 'reality'. The limits of a classical 'description' in quantum mechanics therefore came to signify for Heisenberg, the limits of 'objective reality'. While Bohr exerted perhaps the most important philosophical influence on Heisenberg, their intellectual relationship was characterised by disagreement and misunderstanding. This is most strikingly displayed in their respective views on wave-particle duality and complementarily. While after 1927 Heisenberg accepted Bohr's basic insight that our knowledge of the quantum world is mediated through classical language, he did not share Rohr's interpretation of complementarity. While Heisenberg certainly used terms such as 'complementarity' and wave-particle duality' in his writings, a close reading reveals that these terms had very different meanings for the two physicists. This is particularly evident in the contrast between Heisenberg's notion of wave-particle equivalence and Bohr's idea of complementarity. In bringing to light these divergences between Bohr and Heisenberg, this thesis lends further weight to the view - already advocated by scholars such as John Hendry and Mara Beller - that the so-called Copenhagen interpretation of quantum mechanics should not be thought of as a unified philosophical position, but actually comprises a number of different strands.
W. Heisenberg's treatise “Reality and its order” is a philosophical work of a scientist and philosopher and reflects the totality of his views on various aspects of reality. In this article, the author attempts to analyze the central concepts of quantum mechanics, “state” and “time”, as well as to determine how relevant the ideas of the treatise may be in the world of modern natural science. This point seems especially important, given the time of writing the treatise (no later than 1942), which gives reason to recall the philosophical foundations on which physics rests, and give them a new interpretation that meets modern challenges. The article shows the need to build modern physics on the principles of metaphysics, that is, to study the subject of physics from the position that the world has a metaphysical basis. Statements about the nature of time by various authors are given: from ancient natural philosophers (Aristotle) to medieval thinkers (Augustine, Grossetest), as well as modern researchers (A.Yu. Sevalnikov, Yu.S. Vladimirov, V.D. Zakharov), etc.
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.
I am very grateful to the Master and Fellows of Trinity College for inviting me to give the Tarner Lectures. What I want to do in this book, stated boldly and baldly, is to consider the relevance of developments in modern theoretical physics to metaphysical questions about the ultimate nature of reality. By metaphysical questions I mean the very general sorts of questions that arise out of a critical examination of the principles, concepts and fundamental presuppositions that lie behind modern physics. How should we interpret the claims that physicists seem to be making about the world? Are they intended to be understood as literally true, for example, and exactly what are those claims, given that the pages of theoretical physics monographs are largely filled with abstract mathematical formalism? In the first chapter, I shall be looking at a range of philosophical points of view in the framework of which such questions can be addressed, and attempt the difficult task of adjudicating between the different approaches. At the end of the day I shall be arguing for a pretty straightforward metaphysical realism, that the external world exists independently of our knowledge of it. In the second chapter I shall look at arguments from various branches of modern physics that are sometimes claimed to bring in an essential role for subjectivity in physics, bringing the observer into a central role, creating his own reality.