by Roland Omnès (Trans Arturo Sangalli)

Princeton University Press, Princeton NJ, 1999

ISBN 0-691-02787-0

£17.95

(Review by Chris Clarke)

Roland Omnès’ book is unmissable. Over the last 15 years, traditional Quantum Theory has been radically superseded. This is the first clear, generally accessible account of the new approach which is revolutionising physics, and of how it could totally transform our world view. It is required reading for anyone concerned with our place in the world. It is also, I personally believe, profoundly and seriously wrong.

The core of the book is an exposition of the replacement of the older interpretations of Quantum Theory through the widespread adoption of the consistent histories approach. This regards quantum theory not as a theory about the evolution of exotic objects like the wave-functions, but as a theory about the probabilities and possibilities for the occurrence of particular sorts of sequences of events (called "histories"). Although there are still some contenders for alternative approaches (such as those of Penrose and of Percival), it seems very likely that the consistent histories interpretation, which elucidates so many of the perplexities of previous approaches, will shortly become accepted scientific orthodoxy. Older views, including the idea of the "collapse of the wave-function," will continue to be useful as teaching aids within a limited context, but will cease to have any claim to be taken seriously as fundamental theories. This deserves stressing, since so many popular accounts still ignore the consistent histories approach, or even base themselves on fringe theories such as the many-worlds view, held by tiny minorities of physicists.

Within this context—which I believe is the best we have for making sense of current physics—Omnès puts forward a triumphalist defence of an original and sophisticated form of physicalism. According to him, the world rests on the double pillars of what he terms Reality and Logos, both of which have now, he claims, been discerned by physics through its investigation of quantum phenomena. Logos is expressed through the pure formalism of mathematics, while Reality, remaining irreducible to formalism, is what actually emerges in conformity with the Logos. Common sense, to do with the world of macroscopic experience, derives from these through the evolution of the human brain, though common sense is fundamentally different from both Logos and Reality. In this way philosophy is grounded on the "rock-solid principles of physics." (p 194)

Vital to Omnès’ argument is an essential dichotomy between the quantum and classical realms, based on the success of recent calculations that explain in detail how the classical realm emerges from its quantum foundations. This means that Quantum Theory, while being fundamental to the universe, has no direct relevance to human experience. "There are no cogent arguments for not granting that all of science, except for [particle and atomic physics, including some fragments of chemistry], is perfectly classical and belongs to ordinary reality." (p224) In other words, those who look to Quantum Theory for explanations of consciousness, or for support for a new participatory metaphysics that grounds our place as human beings in the cosmos, are at best indulging in speculation, at worst in "nonsense, twaddle, balderdash, and idle fancies." (p. 198. It would be interesting to check the French original here.) Thus the world of experience is just what traditional, classical physics had always said it was, and Omnès claims that we can be sure of this once and for all because we have now plumbed the fundamental ground of existence and we understand the origin of this classical world.

The argument is developed with skill, clarity and persuasive rhetoric. So, as one who is thereby thrust among the purveyors of balderdash, I am moved to point out some of the lacunae in the argument.

The whole argument rests on a sophisticated form of reductionism. Omnès is reversing the ancient philosophical process of reaching truth from an analysis of direct experience, and instead deducing truth from physical foundations. He thus assumes, with little or no argument, that the whole of experience stems from strictly physical foundations. So he necessarily runs foul of Chalmers’ arguments that consciousness, by its very nature and independently of any details, cannot be so deduced¾ to say nothing of those who draw the same conclusions from transcendental experience.

The history of science and mathematics, occupying the first half of the book, is presented by "staying as close as possible to modern ideas" (p. 13). For Omnès, "modern" means "physicalist," and he thus starts the entire investigation on the basis of the values of scientific orthodoxy. He makes no reference to the feminist critique of authors like Carolyn Merchant who points out that science has been shaped by the politics of the patriarchy from the time of Francis Bacon. In language full of sexual innuendo, Bacon likened the interrogation of nature to the torture of a witch to make her confess. Omnès not only ignores analyses such as Merchant’s, but expresses his admiration for Bacon and echoes his language in claiming that "Nowhere else has the penetrating force of mathematics into the heart of Reality proved so prodigious, and no awl perforates so deep and so well." This slanted approach leads him to ignore all aspects of experience that do not fit with a view of humanity as dominating and controlling nature with perfect clarity of understanding.

While Omnès speaks well of early phenomenalism, his programme of deducing experience from physics, rather than drawing reality from experience, prevents him from following phenomenalism beyond Heidegger. Thus he ignores its later developments which suggest that it is only the dominance of the "modern" patriarchal vision which has forced our experience into the mould of a rigid classical logic. Once the hold of this vision is relaxed, then our experience can move from an alienated observation of classical reality into a flexible co-creative encounter with a reality (physical, emotional and spiritual) in the course of formation. In this mode, we become consciously aware of what is always apparent in the lives of great artists: that both experience and our conceptualisation of it has more in common with the quantum realm than with the classical. In the light of this, we look not only for ways in which the quantum can reduce to the classical, but also for ways in which the quantum can flourish even within the macroscopic realm.

Because Omnès is determined to banish the quantum (with all its uncertainty and insecurity) from human experience, he presents only the argument for how, in the right circumstances, Quantum Theory could produce classical theory. But once we acknowledge the non-classicality of a human life when lived most fully, then we can look for those other circumstances in which classicality may not arise. We can draw on evidence from experience that the human brain has evolved to use non-classicality in a creative manner. This suggests that the consistent histories approach can be employed to describe a world in which the subtleties of the quantum, so well described by Omnès for the microscopic realm, also extend into our life when lived creatively and openly. Indeed, the evidence of parapsychology goes further, indicating that the consistency condition used in "consistent" histories (which is designed to enforce a strictly classical world) may itself be in need of generalising if we are to do justice to experience.

Profound issues are raised by this work about the future course of science and its relevance to humanity’s place in the universe. Those of us who are concerned with integrating science with spiritual experience can no longer rest on general analogies between spiritual apprehension and inadequate versions of quantum theory. There are alternatives to physicalism (however sophisticated it may be) and they need to be developed with a care and rigour equal to that showed by Omnès in this book.