Volition and Physical Laws
| Scientific Paper | |
|---|---|
| Title | Volition and Physical Laws |
| Read in full | Link to paper |
| Author(s) | Jean E Burns |
| Keywords | Emergentism, Quantum randomness, Free will |
| Published | 1999 |
| Journal | Journal of Consciousness Studies |
| Volume | 6 |
| Number | 10 |
| No. of pages | 20 |
| Pages | 27-47 |
Read the full paper here
Abstract
The concept of free will is central to our lives, as we make day-to-day decisions, and to our culture, in our ethical and legal systems. The very concept implies that what we choose can produce a change in our physical environment, whether by pressing a switch to turn out electric lights or choosing a long-term plan of action which can affect many people. Yet volition is not a part of presently known physical laws, and it is not even known whether it exists -- no physics experiments have ever established its presence. (We will use the terms volition and free will synonymously in this article.) The purpose of this article is to make two points: first, that free will cannot be accounted for by presently known physical laws, and second, that if free will exists, any description of its effects in the physical world necessarily would constitute a radical addition to presently known physical laws...
Overview
Jean E. Burns, a consciousness researcher writing in the Journal of Consciousness Studies, sets out to establish two propositions and to survey the consequences of holding both. The first is that free will cannot be accounted for by physics as it now stands, since present laws "encompass only determinism and quantum randomness, and neither of these are what is meant by free will." The second is the sharper one: if free will does exist, then any statement of how it produces effects in the physical world would itself be a radical addition to physical law — not a philosophical thesis about the mind, but new physics.
The argument's force comes from its refusal to let either camp escape. Philosophers such as Kim, McGinn, Dennett and Searle, who identify free will with brain processing obeying known physics, are told that on their own account free will is an illusion with no causal efficacy, since none of them proposes any addition to physical law. Dualists and panpsychists are told that even if consciousness is wholly mental, "free will must produce physical effects (otherwise, it is not free will)", and the characteristics of those effects are physics whether one likes it or not. Burns is careful to note that volition must be limited: "if volition could act anywhere ... to do anything, we should be able to lift a piano by sheer willing as easily as raising an arm." So the required addition to physics must specify not only a mechanism but its constraints.
The paper is dissident on a further axis. It takes seriously the incompatibility of special relativity with any universal present moment, and it treats the Moon-Spencer theory of universal time as a live alternative to Einstein's — one which, unlike special relativity, permits the ordering of events that volition seems to require.
The argument
Ordinary versus radical emergence
Burns distinguishes two things called emergence. Ordinary emergence is when new properties appear from combination but are still determined by known laws — a proton and an electron making a hydrogen atom, or quantum nonlocality in correlated systems. Chaotic and biological systems belong here too: a tornado is unpredictable but not thereby free. Radical emergence would be the appearance of properties not determined by known laws, and requires a new physical principle.
She then dismantles Scott's (1995) argument that consciousness might arise by ordinary emergence. Scott cited the Hodgkin-Huxley equations for ionic currents along a neuron membrane as an example of a physically-determined process whose equations are not time-reversible, and hence appear incompatible with the dynamical laws they derive from. Burns replies that this is not special: heat flow, diffusion and chemical reactions all share it, and are called thermodynamic processes. Every proposed resolution of the dynamic-thermodynamic asymmetry brings in factors beyond the system's internal dynamics — Zurek and Paz's environmental decoherence, or, in an isolated system, the randomising effect of vacuum radiation amplified through molecular collisions (a result of Burns's own 1998 work). Since the apparent contradiction dissolves, there is no example of a physical process supporting the analogy Scott needs. Combining this with Chalmers's argument that consciousness cannot be traced back to physical concepts such as mass and velocity, she concludes that if consciousness arises from the physical world at all, it must do so by radical emergence — which is to say, by a new law.
Why ordering randomness is not randomness
The most-discussed gateway is that volition selects among the alternatives of a quantum random event. Burns argues carefully that this cannot be done for free. In a genuinely random sequence each event is independent of history, so probabilities multiply. If the chance of your standing up and reciting a nursery rhyme is 1 in 100, doing it three times running has probability one in a million — but "in a volitional sequence ... you can recite it three times whenever you want." Any influence that makes an originally random process less random is an ordering of it, and ordering is not something randomness can do. She also rejects the suggestion that volition should preserve the same averages as the underlying random process, showing it leads to absurdity in both forms: constrain a single person over time and you could not repeat the act for three thousand years; constrain a group and your reciting today prevents a million other people from doing so, "not because of their individual preferences, but because you have already done it."
Two quantum gateways and their costs
If volition acts through wave function collapse — as Goswami, Stapp and Walker have proposed — then the system must have quantum coherence, which thermal motion at body temperature seems to preclude at the cellular level, though it might survive in structures such as microtubules (Penrose). A magnification process would then be needed to bring a microtubule-scale collapse up to the level of neural processing, which conveniently explains why volition is not observed directly. But Burns presses the awkward corollary: this does not explain why volition cannot act on macroscopic coherent systems such as superconductors, so further physical specifications constraining its action would be required.
The alternative gateway is quantum fluctuation within the uncertainty principle limits, whose r.m.s. coordinates, following Abbott and Wise, behave like Brownian motion, and which can equally be viewed as driven by vacuum radiation. Wilson (1999) analysed what such fluctuations could physiologically accomplish and showed volition cannot work by shifting any single molecule or molecular component — the protein gate of a sodium channel cannot be held open long enough within those limits. Burns's suggestion is that volition might instead simultaneously order the thermal motions of many water molecules near the gate, each within uncertainty limits, and she is candid that the number required is undoubtedly very large and has never been calculated.
Why volition cannot be a new field
She rules out the simplest proposal cleanly. A volitional field would have to interact with electric charges, since all cognitive processing runs on currents and potential differences; it would therefore be a new constituent of the electromagnetic field. But electromagnetism is unified with the weak force in a theoretically understood and experimentally verified way, and adding a constituent "would not be consistent with known data." Libet's "conscious mental field" escapes this only by being mental rather than physical — but its physical effects still constitute new physics, and would carry testable limitations, such as how large a gap in severed neural tissue the field could bridge.
Reflection spaces and catastrophe structures
Hagelin's identification of consciousness with the unified field is rejected on the ground that the unified field just is the four known fields and so cannot supply what volition needs. Burns finds more promise in Sirag's proposal. Every unified field theory contains an eigenvalue or "reflection space" defined by the set of simultaneously observable quantities — A4 for SU(5), E8 for the E8×E8 string theory. A mathematical theorem allows a reflection space to be extended to two distinct hyperdimensional spaces; if one describes the physical world, Sirag proposes the other describes Universal Mind, with consciousness as their intersection. The attraction for Burns is that reflection spaces are intimately associated with catastrophe structures, which magnify small changes — so volition could act as a very small perturbation and still have macroscopic consequences.
Energy conservation is not the objection it seems
The classic argument against free will is that an unforced physical change violates conservation of energy. Burns summarises Mohrhoff (1999) to defuse it. Conservation of momentum follows from the homogeneity of space and conservation of energy from the homogeneity of time, but only given two further conditions: locally flat space-time (acceptable here, since gravity is negligible for brain processes), and that all forces be describable by a Lagrangian. "Therefore, if volition entails genuine freedom, and its action is not completely prescribed by some mathematical function which depends on physical conditions, then it need not conserve energy or momentum." The physical world can consistently be regarded as open with respect to free will. This lets Burns sharpen her definition of free will to "an influence on physical events which corresponds with mental intention and causes a physical change which would not otherwise occur in identical physical circumstances", with the added requirement that the influence be "neither random nor entirely prescribed by mathematical law."
The present moment and special relativity
The paper's most pointed physics section argues that volition needs a present moment and special relativity denies it one. For two events with a space-like separation, some frames order them one way, some the other, and one frame makes them simultaneous; chaining these — E1 simultaneous with E2, E2 simultaneous with E3 — implies E1 and E3 are simultaneous, even though all observers who compare them directly agree E1 came first. "Our search for a moving present which can be consistently defined across all reference frames leads to the conclusion that in some sense all events coexist."
Retreating to a present moment travelling along one person's worldline does not save it, as the twin paradox shows. If a twin travels at 0.8c for what earth clocks record as 20 years, only 12 years pass on the ship. If the present moment advances along each worldline at the rate of that person's own clock, and both were in the present at departure, and the stay-at-home twin is in the present at the reunion, then the traveller's present moment is 8 years in her own future — "the stay-at-home twin is interacting with a zombie-like replica of her sister." Patching this so that the present always coincides when people meet would require the rate of advance to adjust itself to the traveller's intended destination. Burns notes that Einstein followed the logic to its end, calling the distinction between past, present and future an illusion, and saying that a being who understood the lawful universe would "smile about man's illusion that he was acting according to his own free will."
The theory of universal time
The alternative Burns explores is that of Moon, Spencer and co-workers. Einstein, faced with the choice of assuming either the one-way speed of light or the time a signal arrives at a distant station, assumed the former; universal time theory assumes the latter — all observers agree on the arrival time. The consequence is that light travels at c in the rest frame of its source, and at a slightly different speed in other frames. Predictions have been compared with special relativity for five experiments — Michelson-Morley, Doppler shifts from binary stars, Michelson-Gale, Sagnac, and stellar aberration — and have matched the data as well as special relativity does. Burns is scrupulous about one point: she states flatly that Spencer and Shama's claim to beat special relativity on stellar aberration "is incorrect", their assertion that special relativity predicts no aberration being fallacious, and that when properly adjusted the two theories make identical predictions. She also notes the theory requires modified electromagnetic equations whose symmetry properties would have to be compatible with electroweak unification, and that "it remains to be seen if these requirements can be satisfied."
The end of physics?
Burns reviews the claim (Horgan, Lindley) that fundamental physics is nearly complete: the Standard Model's twelve matter particles and twelve force carriers, string theory as the likely route to including gravity, and a predicted "desert" of energies above accelerator reach in which nothing new is expected. Her response separates the domains: the end-of-physics discussion concerns particle physics, and "the term 'consciousness' is not even listed in the physics abstracts." So it is no argument against volition — but neither does it help, since volition still requires an addition. Her conclusion is conditional and clean: "If volition exists, then physics stands at a new frontier."
Assessment
The paper's real strength is analytical hygiene. Burns holds a distinction that most writing on free will blurs — between randomness and choice — and applies it evenhandedly to physicalists and dualists alike. The nursery-rhyme calculation is a genuinely clarifying device: it shows that "quantum indeterminacy leaves room for free will" is not an explanation but a change of subject, because an agency that reliably orders outcomes is by construction doing something randomness cannot. Equally valuable is her insistence that every proposal be pressed for its limitations, not just its gateway. The superconductor objection to the wave-function-collapse route is exactly the right question to ask, and it is the sort of question proponents of that route generally do not ask themselves. Her handling of the Scott argument is a small model of fair criticism: she grants the observation about Hodgkin-Huxley, locates it in the much larger class of thermodynamic irreversibilities, shows that the standard resolutions work, and only then concludes the analogy fails. And the intellectual honesty of correcting Spencer and Shama's aberration claim — while writing sympathetically about their theory — is notable, and rare.
The difficulties are real but mostly of scope rather than of error. The paper is a survey with a thesis, and the thesis is essentially negative: nothing now known accounts for volition, so something new is needed. What that something is remains entirely open at the end. The positive suggestions are correspondingly thin. The proposal that volition might order the thermal motions of many water molecules near an ion gate is offered with the admission that "no quantitative calculations have presently been made" — and the number matters enormously, since ordering N independent fluctuations to a common purpose is exponentially improbable in N, which is precisely the difficulty Wilson's analysis raised for the single-molecule case. Sirag's reflection-space proposal is reported rather than assessed; the mathematical theorem that a reflection space extends to two hyperdimensional spaces is a fact about Lie algebras, and the identification of the second extension with Universal Mind is an interpretation carrying no independent support. The appeal to catastrophe structures as an amplifier is likewise a hope rather than a calculation.
The relativity sections are the most consequential and the most exposed. Burns's argument that special relativity admits no universal present is correct and is not controversial among physicists; the question is whether volition genuinely requires one, and the paper asserts rather than argues that it does — a block-universe account in which choices are real features of a worldline, not events awaiting a moving Now, is not seriously considered. Her treatment of universal time theory is where a specific conflict with measurement arises. A source-dependent light speed is the defining feature of emission theories, and these are excluded by measurement to high precision: de Sitter's binary-star argument, in its modern X-ray form (Brecher 1977), bounds any source-velocity dependence at the level of about 2 × 10−9. Burns lists Doppler shifts from binary stars among the five successful comparisons but does not engage with the aberration-free timing argument that makes binaries decisive. She is right that the theory has not been ruled out by the experiments its authors examined; the harder point is that the experiments most likely to rule it out were not among them. She is also right, and unusually forthright, that the theory's compatibility with electroweak unification is unknown — which for a 1999 paper is a fair statement of the position, but leaves the alternative resting on an untested foundation.
Read on its own terms the paper does what it sets out to do, and does it rigorously: it establishes that free will is not a philosophical add-on to physics but a demand for new physical law, and it maps the possible gateways honestly, including the reasons each is unsatisfactory. Its weakness is that the case for the universal-time detour rests on the presupposition — never defended — that a real present moment is required for real choice.