We have lived with scientific “monism” since Newton. Monism is the view, shared by virtually all scientists, that the world is made of one kind of “stuff,” the Actual world of matter and energy and with some question marks, space and time and information.
There are very good grounds to accept monism, and it has an ancient history. No less an ancient philosopher Empedocles said, “What is real in the universe is what is actual."
Aristotle was less sure, he toyed with the idea that both the Actual and the Possible were “Real." He called the Possible “potentia” and meant a variety of things by Potentia. And no less a mathematician and philosopher than Alfred North Whitehead, he of Principia Mathematica in the early 20th Century, written with Bertrand Russell, moved on to think of both Actuals and Possibles as “real”, or “ontologically real”, meaning two kinds of “stuff,” Actuals and Possibles in the universe.
I’m beginning, to my surprise to think Aristotle and Whitehead may have been right.
If so, the implications are radical.
I’m beginning to think of a dualism, not the Res Extensa and Res Cogitans of Descartes, but a new Res Extensa and Res Potentia.
We have arrived at our monist views by the enormous successes of classical physics, starting with stunning Newton himself. Consider:
- Aristotle gifts us a model of scientific explanation: deduction. All men are mortal, Socrates is a man, therefore Socrates is a mortal. I ask you to feel the logical force driving you from premises to conclusions, for this very logical force in part underlies our sometimes belief that the laws of nature “force” how nature behaves, they “govern” the universe, rather than describe it.
- Newton invents his famous three laws of motion, invents the differential and integral calculus, whose solutions require the initial conditions of, say, the billiard balls on the table and the boundary conditions, the edges of the table. Given the initial positions and momenta of the balls, and the boundary conditions, we integrate Newton’s three laws of motion, where integration is precisely deduction, to derive from the initial Actual positions and momenta of the balls, the Actual positions and momenta of the balls at the next “instant” and at any future or past moment of time. There are Possibles in Newton’s world. Given the present position and momenta of all the balls, the future and past determined positions and momenta are in a weak sense Possibles, but since the equations are determinsitic, there is only one possible future or past position and momenta of all the balls at any moment. As Dieter Zeh says, quoted below, here we mean by the word “possibles” that only one of them is “real”. As Laplace said: Given sufficient information about the positions and momenta of all the particles in the universe, and Newton’s laws, the entire future and past of the universe is determined.
- Einstein’s probable culmination of classical physics is the gigantic General Relativity. In a whirlwind triumph of courage, imagination, and mathematics, Einstein constructs a world view of a four dimensional spacetime block universe in which there are no Possibles at all. All that exist are four dimensional “world lines” spanning the block universe. No Possibles at all, Empedocles triumphant 2700 years later.
But is it so? A powerful doubt was raised before Newton by Descartes, whose invention of analytical geometry paved the way for calculus. Descartes thought the world consisted of two substances, mind stuff and matter stuff, Res Cogitans and Res Extensa. If you are reading this blog, you know perfectly well what mind stuff is, it is your awareness of what you are seeing and understanding... whatever that is.
Well, Descartes’ dualism, Res cogitans and Res Extensa have not fared well given classical physics and its vast successes. No, nothing but Actual Res Extensa, thank you.
Descartes’ dualism is essentially dead.
But maybe Descartes was not entirely wrong.
I begin to suspect that Rene’ Descartes was on to something we live with, Res Potentia, the Possible along with Res Extensa, the Actual. The rest of this blog spells out why I suspect this.
A central reason to suspect that Res Potentia is real, ontologically real, is Quantum Mechanics itself.
However, I want to begin with a point made in a different context by American philosopher, Charles Sanders Pierce in the 19th Century. Pierce noted three “modalities,” the Actual, the Possible, the Probable. All this bears on Aristotle and his famous “law of the excluded middle.” Consider the statements “A” and “Not A.” There is nothing, said Aristotle, that is in the “middle” of A and Not A. One or the other. Only one or the other, not both.
But wait, said Pierce, “A is True,” “A is possibly true and simultaneously possibly false”, “A is false.” The “Possible” evades the law of the excluded middle, indeed it is smack in the middle between “A is True” and “A is False”.
Now consider the famous two slit experiment with its well known photon gun squirting photons at one per minute at a barrier with two open slits and a photo-detector screen on the far side. We all know the results: One sees the famous interference banded pattern of light and dark bands spanning the detector screen between where bullets would hit the screen if passing via slit 1 or via slit 2. So light is behaving as a wave. And, in the Copenhagen interpretation, upon which I will depend, we can say of the photon that it is possible that the photon went through slit 1 and also at the same time it is possible that the photon went through slit 2. Indeed, in R. Feynman’s wonderful “sum over all possible histories formulation of quantum mechanics, we say that the single photon simultaneously took all the possible pathways at the same sequence of time moments, from the photon gun, through both slits, to the detector screen. We cannot say the photon “really” went through slit 1 or slit 2.
Quantum Mechanics, it seems safe to say, evades the law of the excluded middle! Classical physics does not!
Hear physicist Dieter Zeh:
In classical physics you can and do assume that only one of the possibilities is real (that is why you call them possibilities). It is your knowledge that was incomplete before the observation. Mere possibilities cannot interfere with one another to give effects in reality. In particular, if you would use the dynamical laws to trace back in time the improved information about the real state, you would also get improved knowledge about the past. This is different in quantum theory (for pure states): In order to obtain the correct state in the past (that may have been recorded in a previous measurement), you need all apparent "possibilities" (all components of the wave function -- including the non-observed ones). So they must have equally been real.
Zeh, too, is saying that the quantum possibilities are simultaneously real and avoid the law of the excluded middle.
But things get worse with the famous Bell’s inequalities, now very well established experimentally, and which grow out of the 1935 Einstein, Podolsky, Rosen paper. Bell’s inequalities have to do with “entangled quantum particles” and it is important for this discussion to read about it. For now, the conclusion is my focus. Given the experimental results, we are forced either to abandon “locality” in physics, or we are forced to abandon “the Definiteness of CounterFactual Statements!” Now giving up locality, i.e. non-locality, is generally not welcomed by physicists, who want to believe that Actual events have spatially local Actual causal consequences.
Then, I suggest, what about giving up “The definiteness of counter-factual statements”? A counterfactual statement is something like this: “A caused B, and if A had not occurred (contrary to fact), B would not have occurred.”
But the definiteness of counterfactual statements rests on the law of the excluded middle. Try the above with “A occured and B possibly occurs but B also simultaneously possibly does not occur. Then the hoped for counter factual becomes: (contrary to fact) A did not occur so B neither possibly occurs nor does it simultaneously possibly not occur. This is not a definite counterfactual statement at all. It is nonsense.
Possibles evade the definiteness of counterfactual statements.
We are struggling with non-locality as the interpretation of quantum mechanics, given an interpretation of quantum mechanics purely in terms of a world comprised only of Actuals. Grant the reality of Actuals and Possibles, Res Extensa and Res Potentia, and we no longer need non-locality in physics to account for the EPR experiments, confirmed, and Bell”s inequalities.
Not having to give up locality in physics is, in fact, a theoretical triumph, for we have not the faintest idea how non-locality might occur beyond odd speculations about non-locally connected graph structures of space. Before we dismiss Res Extensia and Res Potentia, Occum might (barely) trade keeping locality and purchasing Res Extensia and Res Potentia.
“If you think you understand quantum mechanics, you have not thought about it.” said Feynman. Yes, and I am not a physicist, so caveat lector.
We have 70 years of struggle to meld General Relativity with Quantum Mechanics, so far to no clear success. The general claim is that General Relativity is nonlinear and Quantum Mechanics is a linear theory so it is hard to meld the two. Yes. But also, I now want to claim, General Relativity is based only on ontological Actuals. Quantum Mechanics, I claim, is fully interpretable in terms of ontologically real Possibles. Res Potentia and Res Extensia, the quantum world and the classical world. Quantum Mechanics is consistent with a different ontology than General Relativity, one that allows Res Extensa and Res Potentia! Then two obstacles impede uniting General Relativity and Quantum Mechanics, non-linearity versus linearity, and much more profoundly, I claim, the fact that Quantum Mechanics may be our best, but not only, evidence for the reality of “the Possible, Res Potentia.
On this new dualism, Res Extensa and Res Potentia, what is then waving in the mathematical formalism of Quantum Mechanics is exactly what physicists say, but don’t mean, the waves are waves of real “possibilities”. Then when you square the amplitudes of the waves you get probabilities, Born’s rule, and thank goodness Probabilities obey the law of the excluded middle. We are back on safe turf of the Actual, just what Dieter Zeh denies for quantum possibilities in the two slit experiment.
There is other speculative, but serious arguments from cosmology and the “multiverse”, where Stanford physicist Leonard Susskind pictures baby universes being born from a “limbo” of potential universes. What is a “potential universe”? Res Potentia. In my own blog, titled somewhat timidly, “In the Beginning: A Creation Myth”, I too start with “The Possible” and its conceivable evolution.
But there are other strong arguments. Since Descartes’ dualism, Res Extensa and Res Cogitans, we have been struggling with the issue of how mind can “act on” matter. If the mind-brain system is “identical,” and the brain is a deterministic system, then the brain, like the table of billiard balls, is a deterministic sequence of Actual states and entirely sufficient to account for its own dynamical behavior. Then there is “nothing for mind to do, and worse, no way for mind to do it!” Is mind in some ghost-like way to alter the deterministic behavior of the brain, or a table of billiard balls? No. Stochastic equations that hide epistemological ignorance do not help here.
In two books, Investigations (Czech version) and Reinventing the Sacred, I have argued that the mind brain system is both quantum and classical and indeed lives in a new “Poised Realm” between the quantum and classical worlds.
Evidence for the existence of the Poised Realm will be noted in a moment. Then I argue, the mind brain system is quantum coherent and does NOT act on the brain causally at all. Rather it acausally decoheres to classicity (for all practical purposes) as is well studied, thus acausally has consequences for the classical “Actual brain.” I believe this idea solves a riddle with us since Descartes, how the mind can “act on matter?” It does not act causally at all, as noted, it decoheres acausally to classicity, with consequences for the matter of the brain. I feel it is not trivial to find a candidate solution to a philosophy of mind problem that has plagued us for almost 350 years.
For this transition from quantum to classical to occur repeatedly I must argue that the mind brain system repeatedly passes from quantum to classical then back to quantum via a Poised Realm that really exists and separates the two.
Does such a poised realm exist? Is there evidence that “decoherence” to classicity back to quantum behavior can arise? There is growing powerful evidence that a Poised Realm does exist, and that transitions from quantum to classical and from classical to quantum can occur in the Poised Realm.
Decoherence, the loss of phase information, in now the favored interpretation of the emergence of the classical world from the quantum “haze” of what I claim are real possibilities. But the process can go from classical to quantum and back, as seen in papers on quantum coherent entangled states that can “suddenly die” to classicity then revive to quantum coherent entanglement! More, chlorophyll wrapped by its antenna protein is quantum coherent for some 7000 femtoseconds, when the normal time of decoherence should be about a femtosecond. Either the evolved antenna protein is able to entirely block decoherence, which seems unlikely, or it partially induces ‘RECOHERENCE”. I think the latter is more probable. Finally, as I have blogged about before, Shor’s theorem states that in a quantum computer whose entangled qubits are decohering, some qubits can be measured, information can be injected into the now OPEN quantum system in an environment, and the decohering qubits CAN BE MADE COHERENT AGAIN. The system moves in the Poised Realm from partially decoherent to fully quantum coherent.
A final piece of theoretical and experimental evidence for the reality of a Poised Realm, that I blogged about six months ago, are recent theory and experiments about what is called the AntiZeno Effect, where quantum transitions are not “Markovian” as in radioactive decay with its familiar exponential half life, but non-Markovian with non-exponential behavior. The Poised Realm is real, itself a new aspect of “reality”. We have much to learn about this new realm between the quantum and classical worlds.
I believe that there is are TWO new realms of reality: Res Potentia, real possibilities, along with Res Extensa - quantum and classical, possible and actual, and a Poised Realm between fully quantum and “fully” classical behavior where the possibles of the quantum world can reversibly “become actual” over a real passage of time, for example by decoherence and recoherence. In fact, I strongly suspect that life itself lives in the Poised Realm, poised between quantum coherence and classicity, with new implications for the physics of life, medical implications and other consequences to be discovered.