Online research in philosophy

Summary In this report on the present state of the discussion about the interpretation of quantum mechanics an attempt is made to provide an idea of the philosophical relevance of the foundations of physics. A simplified model of the measuring process is given which shows the difficulties in the interpretation of quantum mechanics. It is argued against Bohr's solution (also in a version of H. Putnam). Two examples show possible philosophical consequences of quantum mechanics: The variety of quantum logics challenges the foundations of logic, the paradox of Einstein, Podolsky and Rosen (with Bell's inequality) may be interpreted along the lines of holism. Against alleged refutations of realism by means of quantum mechanics, a realist standpoint is maintained. A proper interpretation of quantum mechanics from an epistemological point of view seems still to be lacking.

The aim of this paper is to contribute to a more balanced judgement than the widespread impression that the changes which are called for in today's philosophy of physics and which centre around the concept of holism amount to a rupture with the framework of Cartesian philosophy of physics. I argue that this framework includes a sort of holism: As a result of the identification of matter with space, any physical property can be instantiated only if there is the whole of matter. Relating this holism to general relativity, I maintain that this holism cannot be directly applied to today's philosophy of physics consequent upon the failure of geometrodynamics. I show in what respect precisely the holism in quantum physics amounts to a revision of the holism within Cartesianism.

Aiming to unravel the mystery of quantum mechanics, this book is concerned with questions about action-at-a-distance, holism, and whether quantum mechanics gives a complete account of microphysical reality. With rigorous arguments and clear thinking, the author provides an introduction to the philosophy of physics.

Motivated by the question what it is that makes quantum mechanics a holistic theory (if so), I try to define for general physical theories what we mean by `holism'. For this purpose I propose an epistemological criterion to decide whether or not a physical theory is holistic, namely: a physical theory is holistic if and only if it is impossible in principle to infer the global properties, as assigned in the theory, by local resources available to an agent. I propose that these resources include at least all local operations and classical communication. This approach is contrasted with the well-known approaches to holism in terms of supervenience. The criterion for holism proposed here involves a shift in emphasis from ontology to epistemology. I apply this epistemological criterion to classical physics and Bohmian mechanics as represented on a phase and configuration space respectively, and for quantum mechanics (in the orthodox interpretation) using the formalism of general quantum operations as completely positive trace non-increasing maps. Furthermore, I provide an interesting example from which one can conclude that quantum mechanics is holistic in the above mentioned sense, although, perhaps surprisingly, no entanglement is needed.

There have been suggestions that the unity of consciousness may be related to the kind of holism depicted only in quantum physics. This argument will be clarified and strengthened. It requires the brain to contain a quantum system with the right properties — a Bose-Einstein condensate. It probably does contain one such system, as both theory and experiment have indicated. In fact, we cannot pay full attention to a quantum whole and its parts simultaneously, though we may oscillate between the two. In a quantum theory of consciousness, emergent meanings arise as an inevitable consequence of Heisenberg''s Uncertainty Principle.

The present essay aims at broadening the recent discussion on the issue of holism vs. particularism in quantum physics. I begin with a clarification of the relation between the holism/particularism debate and the discussion of supervenience relation. I then defend particularism in physics (including quantum physics) by considering a new classification of properties of physical systems. With such a classification, the results in the Bell theorem are shown to violate spatial separability but not physical particularism.

It has sometimes been suggested that quantum phenomena exhibit a characteristic holism or nonseparability, and that this distinguishes quantum from classical physics. One puzzling quantum phenomenon arises when one performs measurements of spin or polarization on certain separated quantum systems. The results of these measurements exhibit patterns of statistical correlation that resist traditional causal explanation. Some have held that it is possible to understand these patterns as instances or consequences of quantum holism or nonseparability. Just what holism and nonseparability are supposed to be has not always been made clear, though, and each of these notions has been understood in different ways. Moreover, while some have taken holism and nonseparability to come to the same thing, others have thought it important to distinguish the two. Any evaluation of the significance of quantum holism and/or nonseparability must rest on a careful analysis of these notions.

The claim of this paper is that we should envisage physicalism as an ontological holism. Our current basic physics, quantum theory, suggests that, ontologically speaking, we have to assume one global quantum state of the world; many of the properties that are often taken to be intrinsic properties of physical systems are in fact relations, which are determined by that global quantum state. The paper elaborates on this conception of physicalism as an ontological holism and considers issues such as supervenience, realization of higher-order properties by basic physical properties, and reduction. Keywords: physicalism, holism, relations, space-time, quantum physics, Humean supervenience.

Quine’s holism and holism in quantum physics are usually considered to be two different issues which merely have the name “holism” in common. My aim, by contrast, is to build a bridge between these two sorts of holism. This paper is an argument for three theses: 1) The discussion on holism and other options in the interpretation of quantum physics is one paradigmatic example of Quine’s confirmation holism in the philosophy of physics. In particular, taking Quine’s holism into account puts the claim of experimental metaphysics in the interpretation of quantum physics into perspective. 2) Quine’s criterion for changes to our system of knowledge enables a rational evaluation of the options in the interpretation of quantum theory. In particular, this criterion supports the option for quantum holism. 3) The meaning of “holism” in Quine’s thesis about statements and the meaning of “holism” in what quantum theory says about physical systems exhibit a far-reaching analogy. According to Quine’s seminal paper “Two Dogmas of Empiricism” (first published as Quine (1951)), four features are central to his holism: [52] a) There is no separation between science and philosophy in the sense of metaphysics. b) Experience confirms or disconfirms a scientific hypothesis only together with a cluster of background assumptions that finally encompass the whole of science. c) We always have a number of options to adapt our system of knowledge to new experience. It is rational to endorse that option which implies the lest overall change to the system as a whole. d) Only a cluster of statements and ultimately only the whole of science has meaning. My argument for my first thesis is that a) and b) can be applied to the interpretation of quantum physics. I argue for my second thesis by claiming that c) supports the option for quantum holism. To make a case for my third thesis, I compare the characterization of science which b) and d) imply with the characterization of nature at the microphysical level that quantum theory implies according to the option for quantum holism. To begin with, I briefly recall Quine’s confirmation holism (section 2)..