Von Neumann’s Measurement Chain without Dualism: Subjective Perception as the Natural Endpoint under Phenomenological Absolutism and Mutual Exclusivity
Von Neumann’s 1932 analysis of the quantum measurement chain establishes that unitary evolution can be extended through any physical apparatus or the observer’s body, and that the formalism supplies no intrinsic criterion for locating a non-unitary cut. The later rejection of placing that terminus at subjective perception did not follow from a defect in the chain argument. It followed from a physicalist ontology that treats mind and world as ontologically distinct—an assumption the mathematics of quantum mechanics does not require. Under Phenomenological Absolutism and Mutual Exclusivity, each localized actualized field configuration is identical with the absolute is-ness of first-person phenomenology. On that ontology the endpoint is not an extra-physical intervention in a closed material chain. It is what an actualized configuration already is. We reconstruct von Neumann’s position with textual fidelity, distinguish it from later causal claims that consciousness collapses the state, and show that the dualistic objections lose their force once the extraneous metaphysical premise is withdrawn. The mathematics remains compatible with other interpretations. Our claim is that von Neumann’s conclusion fits naturally when the ontology does not smuggle in a subject–object split the theory itself never licensed.
Von Neumann’s 1932 analysis of the quantum measurement chain establishes that unitary evolution can be extended through any physical apparatus or the observer’s body, and that the formalism supplies no intrinsic criterion for locating a non-unitary cut. The later rejection of placing that terminus at subjective perception did not follow from a defect in the chain argument. It followed from a physicalist ontology that treats mind and world as ontologically distinct—an assumption the mathematics of quantum mechanics does not require. Under Phenomenological Absolutism and Mutual Exclusivity, each localized actualized field configuration is identical with the absolute is-ness of first-person phenomenology. On that ontology the endpoint is not an extra-physical intervention in a closed material chain. It is what an actualized configuration already is. We reconstruct von Neumann’s position with textual fidelity, distinguish it from later causal claims that consciousness collapses the state, and show that the dualistic objections lose their force once the extraneous metaphysical premise is withdrawn. The mathematics remains compatible with other interpretations. Our claim is that von Neumann’s conclusion fits naturally when the ontology does not smuggle in a subject–object split the theory itself never licensed.
This thesis is an examination of the measurement problem from within the Copenhagen interpretation of quantum mechanics where I take issue with von Neumann’s theory of measurement which argues for the subjective collapse of the wave function by a conscious observer. I argue that von Neumann’s postulate of collapse has led to several intractable philosophical and conceptual problems in its account of quantum measurement. I argue that these problems arise from von Neumann’s misreading of Bohr’s complementarity regarding the relationship between subject and object as distinct metaphysical entities. Instead, I offer a new way of defining the subject-object relation based on Don Howard’s reading of Bohr’s complementarity as subject-object nonseparability (SON). I argue that the SON principle has the potential of placing Copenhagen on more solid philosophical footing by viewing the subject-object relationship not as a causal relation, but as a relation of ontological dependence to avoid the idea of collapse altogether.
The file has been temporarily restricted while the author reviews the arguments and conclusions.This note examines how ontological conclusions are drawn from the standard quantum formalism. It distinguishes what the formalism fixes from additional claims about objective physical states and about where and when outcomes become fully formed. It tests these inferences by considering a minimal objective-state possibility, without predetermined values for all observables, and by analyzing the underdetermination of where and when outcome formation occurs within a physical measurement chain. Because preserved records themselves become part of that chain, their later comparison does not by itself resolve the underdetermination. The analysis identifies additional premises required for familiar paradoxical inferences and leaves open the possibility of outcome completion through ordinary causal propagation, without choosing an interpretation or constructing a new mechanism.
Abstract As Heisenberg began to promulgate his version of the new quantum philosophy as the ‘Copenhagen spirit’, John von Neumann undertook to purge quantum mechanics of its defects and make it comprehensible to Göttingen’s prince of mathematics, David Hilbert. The result is familiar to any student of physical science. Von Neumann separated the continuous, deterministic, and reversible evolution of the wavefunction from its discontinuous, indeterministic, and irreversible ‘collapse’ in an act of measurement. He saw no reason why the first process should not continue all the way up the chain to the observer’s conscious mind, where the second process occurs. Bohr had little to say about von Neumann’s theory, other than it was ‘wrongly put’. Von Neumann also closed the door that Born had left ajar. Causality could not be restored to the quantum domain by supposing the existence of ‘hidden variables’, as these, according to his reasoning, were mathematically impossible.
Amid the wide variety of interpretations of quantum mechanics, the notion of a fully coherent ontological interpretation has seen a promising evolution over the last few decades. Despite this progress, however, the old dualistic categorical constraints of subjectivity and objectivity, correlate with the metrically restricted definition of local and global, have remained largely in place – a reflection of the broader, persistent inheritance of these comfortable strictures throughout the evolution of modern science. If one traces this inheritance back to its ancient roots in Plato and Aristotle, it is clear that the coherence, scientific utility, and historical durability of the various natural philosophies that followed have been directly proportional to their commitment, tacit or explicit, to object-oriented realism. As Simondon might put it, it is a commitment to the primacy of individuated substance over the process of individuation. For Whitehead, it is the misplaced assimilation of becoming to being, of potentiality to actuality. Quantum mechanics has challenged this commitment with a combined breadth and depth of force that far exceeds any other theory in the history of science. The theory’s objectively demonstrable empirical application is manifest only by way of a fundamentally subjective, context-dependent mechanism of measurement. More compelling still, actual system states are always actualizations of locally contextualized yet globally conditioned potential system states, such that “globally objective” reality is no longer merely the object of local measurement, but also its product. Thus, any coherent, ontological interpretation of quantum theory must include a conceptual framework by which objectivity and subjectivity, actuality and potentiality, global and local, being and becoming, individuated fact and process of individuation, are no longer understood as merely epistemic, mutually exclusive category pairs descriptive of an already extant, closed reality – but rather as mutually implicative ontological categories explicative of an ontogenetic, open reality-in-process.
Contemporary physics finds itself pondering questions about mind and consciousness, an uncomfortable area for theorists. But historically, key figures at the founding of quantum theory assumed that reality was composed of two parts, mind and matter, which interacted with each other according to some new laws that they specified. This departure from the prior (classical-physicalist) assumption that mind was a mere side effect of brain activity was such a startling proposal that it basically split physics in two, with one camp insisting that mind will ultimately be explained via physical processes in the brain and the other camp embracing mind as innate in creation and the key to understanding reality in its completeness. Henry Stapp made important contributions toward a coherent explanation by advocating John von Neumann’s orthodox interpretation of quantum mechanics. von Neumann postulated that at its basis, quantum mechanics requires both a psychological and physical component. He was left, however, with a dualist view in which the psychological and physical aspects of QM remained unresolved. In this article, the relevant issues are laid out with the aim of finding a nondual explanation that allows mind and matter to exist as features of the same universal consciousness, in the hope that the critical insights of Planck, Heisenberg, Schrödinger, von Neumann, and Stapp will be recognized and valued, with the aim of an expanded physics that goes beyond physicalist dogma.
Abstract The orthodox solution to the measurement problem is often presented in terms of ‘consciousness causes collapse’. It is widely taken to have been developed and presented by the mathematician von Neumann in his classic book, Mathematical Foundations of Quantum Mechanics (1932/1955) which lays down the core theoretical framework of quantum mechanics. However, the ‘problem’ was not even presented as such until the 1950s, which is when von Neumann’s book was finally translated into English, and there is barely any mention of consciousness in it. It is partly for this reason that London and Bauer are typically regarded as having clearly articulated what von Neumann only hinted at. This chapter examines what von Neumann actually wrote about measurement in quantum mechanics. It presents his ‘psychophysical parallelism’ and the famous ‘chain’ argument which concludes that something non-physical must induce the wave-function to collapse. The chapter concludes with brief comments on von Neumann’s later thoughts concerning the comparison between computers and the human brain.