On the dichotomy between physicalist reductionism and mind-body dualism, both being failed options:
Reflecting on the complex debates that have swirled around this issue, one feature stands out. On all sides, the presumption has been that the fundamental level of the natural world consists of micro-physical entities of some sort, with their primary properties. These physical entities are clearly some sort of particular. But what sort? Some physicalists believe that it does not matter, that the notion of a physical particular might be defined as an object, a concrete event, or whatever. Howbeit, the key commitment of physicalism is to some kind of
basic particulars
, which are the fundamental constituents out of which everything in the world is composed. Even those who argue for a wide sense of the ‘physical’ erect their definitions of that term upon basic physical constituents. That is, however generous the definition, physicalists take as fundamental
elementary particles
, in the loose sense of the word “particle” commonly encountered in descriptions of quantum mechanical phenomena.
But recent developments in physics tell against that presupposition. What our best contemporary physics reveals is that
there are no elementary ‘particles’
, fundamental events, or some such particulars. There are only
processes
of various scales and complexity. That this is so has not been easy to see, since the behaviour of phenomena at the sub-atomic level has seemed to defy description in coherent and intelligible terms. For more than a century, physicists have struggled to reconcile the facts that these phenomena exhibit, in different experimental circumstances, both particle-like and wave-like behaviour. With so much being discovered that physicists themselves confess to finding weird, the habitual ways of talking about particles persist even though its use is confused and confusing. Even reputable physicists often give explanatory descriptions in terms of ‘particles’ in a way which, if taken seriously, would be incompatible with the physics they are trying to explain. Further, physics throughout the 20
th
Century has been dogged by a series of deep theoretical inconsistencies that are not yet fully resolved. But enough has now become clear for it to be evident that an ontology of elementary ‘particles’ – basic particulars – can no longer be sustained.
To make this clear, it will be helpful to review briefly the major shifts in physical theory in the 20
th
Century. The new era in physics was ushered in when Einstein proposed his special theory of relativity to overcome the contradiction between Newton’s laws of motion and Maxwell’s equations of electromagnetism. But that solution immediately generated another contradiction. According to special relativity, no object, and no force, can travel faster than the speed of light; yet in Newton’s theory, universal gravity is a force that is transmitted instantaneously. Again, it was Einstein who proposed the solution to this second conflict, with his general theory of relativity. Special relativity had held that the motion of one entity relative to another influences space and time. Now, according to general relativity, space and time can warp and curve in response to the presence of matter or energy. Such distortions spread out from one place to another, not instantaneously but at the speed of light, becoming more attenuated with distance.
The general theory of relativity provided for the first time an explanation of what gravity actually is, but until general relativity is integrated with quantum mechanics (as superstring theory now aims to do) ‘particle’-based physics has to treat gravity as an ubiquitous mystery. Indeed, far from overcoming the embarrassment that the apparent action at a distance of gravitational force causes for Newtonian corpuscular physics, recent experimental work has actually produced even worse anomalies for an elementary ‘particle’ metaphysics. For it has discovered a number of non-local phenomena that do not involve the transmission of force. For just one example, the Pauli exclusion principle forbids two leptons (of which electrons are one sort) from being in the same quantum state. Two electrons in the same carbon atom cannot be in the same quantum state. This fact underlies all of chemistry, yet it is an inherently non-local,
relational
constraint. Why should that be? Why should this ‘state’ constraint hold for electrons within a single carbon atom, but not for electrons in two different carbon atoms? And why should these problems go away when we go beyond the quantum level? There are good mathematical explanations for the Pauli exclusion principle, but such non-local phenomena must seem utterly mysterious from the perspective of particle metaphysics – just as Newton admitted that the non-locality of gravity was a deep conceptual anomaly in his physics.
Many aspects of quantum mechanics are well confirmed, but quantum mechanics and relativity theory – both special and general – cannot both be correct. Not only is quantum mechanics incompatible with
general
relativity unless it is transformed in a way that can account for gravity,
special
relativity plus conservation of energy forces a
field
physics, and, therefore, a
field metaphysics
. This is because any transmission of energy from one ‘particle’ to another has to be across some space and will, according to special relativity, take some time. For example, if an electron oscillates in one place and thereby elicits a force on an electron in another place, that force can be felt only after a delay that honours the limitations of the speed of light. But given the law of conservation of energy, it makes no sense to suppose that that energy simply disappears as it leaves the first electron, only to re-appear sometime later, when it arrives at the second. So, there must be a field encompassing both places,
through
which the energy travels. Furthermore, quantum
field
theory involves its own well supported empirical consequences, such as the Casimir effect. It is not just a mathematical but physically irrelevant fix.
In fact, the incompatibility between quantum mechanics and special relativity is overcome by quantum field theory, and superstring theory now aims to overcome the incompatibility between quantum mechanics and general relativity. But despite these achievements, a satisfactorily unified physics is still wanting. A field version of superstring theory has still to be developed, yet quantum fields are still needed to preserve special relativity together with conservation of energy, and to provide for the possibility of explaining non-local phenomena.
Although there is much for physics yet to resolve, the general direction is becoming clear enough for some conclusions of metaphysical significance to be drawn. According to our best science, there are no elementary ‘particles’, or basic particulars, at all; everything is composed of quantum fields. Quantum field theory shifts the basic ontology of the universe from micro-particles to quantum fields. What have seemed to be ‘particles’ are now conceptualized as particle-like processes and interactions resulting from the quantization of field processes and interactions. Those are no more particles than are the integer number of oscillatory waves in a guitar string. Each of the apparent particulars assumed by a physicalist ontology is a quantized field process.
It is just as well that the physicalist’s metaphysical model, which would reduce everything to interactions amongst elementary ‘particles’, is not supported by recent physics, since it is arguably incoherent. Either the basic particulars (particles) have extension, or they do not. If they have no extension, then a field view is forced in order to account for particle interactions, since the probability of such particles ever actually hitting each other is zero. If, on the other hand, these elementary particles do have finite extension, they pose intractable problems for physical theory. They could not be compressible; the velocity of transmission of force through their diameter would therefore be instantaneous; there would be extreme difficulty in explaining different kinds of interactions (gravity, electricity, etc.); and so on. If a move is made to a combination of particles and fields (the typical contemporary semi-sophisticated view), then all the significant issues are already granted anyway in the granting of fields. There are no ‘particles’, but, even if there were, so long as fields are granted at all, the micro-reduction motivation fails – and a strict particle view is not only factually false, but conceptually incoherent as well.
<snip> . . .
The adjustment in one’s physics, however, is not so simple; the particle view is deeply related to the micro-reductivist position. Particles do not
have
a configuration. They are points. But they do
participate
in configurations relative to each other. Particles are the purported locus of causal power, and the configurations in which they participate are ‘merely’ the stage setting for the working out of the particle causal interactions. That is, causal power is resident in entities that are not configurational, and configuration or organization is merely a stage setting, with no causal power of its own. In this view, organization is factored out as a legitimate locus for causal power – it’s just stage setting – and such delegitimation succeeds because there is a non-configurational candidate available to be such a causal locus: particles. The particle view supports the reductionist view by motivating the elimination of configurations as legitimate loci of causal power. So, abandoning a particle physics in favour of a quantum field physics, a process metaphysics, is not an innocent choice with respect to the issues at hand.
The critical point is that quantum field processes have no existence that is independent of their configurations: quantum fields are processes, and can only exist in various patterns. Those patterns come in many sizes, of many different physical and temporal scales, some as large as a human person, or a social institution – but they are all equally patterns of processes. There is no ‘bottoming out’ level in quantum field theory – it is patterns of process all the way down, and all the way up.
That is the rub. To be a reductive physicalist (or an ‘eliminative materialist’) at all, is to believe that ‘higher-level’ entities are nothing other than complex configurations of lower-level entities, in such a way that the higher-level properties and powers are explicable in principle in terms of the properties and powers of the lower-level entities (or at least, determined by them). Consequently, some entity is reducible just in case it is a configuration of lower-level entities. But now the supposed base-level entities are nothing but configurations of process as well! If there is no ‘bottoming out’, there are no bases to which all other phenomena can, even in principle, be reduced. Our reductive physicalist has lost the ground on which he wants to stand.
If being configurational
makes a property or power epiphenomenal, then everything is an epiphenomenon.
That is the
reductio ad absurdum
of this position.
