By The Quantum Revolution
Following Galileo and Newton, physics made a reductionist turn. The most fundamental level of reality was seen to be microscopic particles called atoms or corpuscles. All things were seen to be composed of such particles like legos. What follows from this ontology is a view of the world in which every substance is identical in kind, but different due to the organizational structure. Cats, dogs, humans, and ants are the same as cars, rocks, and golf clubs. According to some thinkers, the mental was conceived as another substance distinct, but somehow conjoined to the physical.
With the quantum ‘anti-scientific’ revolution in the 20th century, the recovery of Aristotelian thinking found its genesis. In three ways do we see this:
- Rehabilitation of teleology
- The macroscopic world recovering its privilege status
- The autonomy of chemistry and thermodynamics from physics
Interpretations
People familiar with quantum mechanics will know that various interpretations abound, and it’s only on the Aristotelian one that the perennial philosophy is recovered. But do we have any reason to accept such an interpretation?
Well, take a look at the others. For instance, the many-worlds interpretation claims that there are literally many worlds each stemming from possible things that can happen in some common history. E.g., Instead of writing this sentence I could have gone to play catch, and so this possibility would be fully real and “split off.”
The Bohmian interpretation claims that the universe is somehow guiding the motion of each particle, thus “making it impossible to isolate interactions from remote and uncontrollable factors.” The objective collapse interpretation claims that there exist undetected parts of quantum theory that aid in determining the structure of the macroscopic world. The Copenhagen interpretation asserts that it is observers which structure the world. And the transactional interpretation claims that the future influences the past.
All these interpretations seem, at least on the face of it, to be wildly contrary to lived-experience, and in violation of theoretical virtues like simplicity and economy. Because of that, there is at least good evidence to prefer the Aristotleian interpretation on which act and potency are real features of the world.
The Aristotelian interpretation also solves a great problem in quantum theory. In the famous double slit experiment it seems that the particles both go through and don’t go through one of the slits at the same time. And in the Schrodinger’s Cat thought experiment, it seems that the cat is both alive and not alive at the same time and in the same respect. At least on some interpretations this would constitute a clear violation of the principle of noncontradiction. But such a thing would come at a very high cost, for a violation of the PNC would seem to entail that it no longer applies to a part of reality. Why then should we trust it in any case? If that’s true, then we have no grounds for trusting the principle of identity or the principle of excluded middle. And if that’s true, well… then science and reason collapse. But clearly, we can reason to things and do some science, so we have to conclude that the PNC and other principles of reason are correct, and hence any interpretation that violates them is false.
This line of thinking already cuts down the competition and gives more good reason to buy into the Aristotelian interpretation. But there’s even more evidence.
It has been claimed by some like Lawrence Krauss that things can “come from nothing” due to quantum fluctuations. But this is a move too far. The confusion here rests on failing to distinguish between act and potency. Something can be undetermined, or in potency to act, and still be caused, as Aristotle thought rational agents were. Quantum particles are not determined precisely because they are in potential to certain actual states, and only brought to such states by an actual agent. Not only does applying the Aristotelian interpretation here square with the physics nicely, it also makes much more sense than speaking in the terms of Krauss.
Furthermore, it may be the case that the Aristotelian interpretation can account for something that Einstein could not. Famously Albert Einstein held that nonlocal causal action (Bell’s Theorem) was “spooky” – mainly because he was operating with the assumption of mechanistic causation. For Einstein, causes only operate in a push/pull fashion, so it’s quite “spooky” to think that an action ‘here’ could have an instantaneous effect on something extremely far away as the EPR thought experiment demonstrates.
It seems that this might not be a problem for an Aristotelian. Since causation is not limited to only push/pull mechanisms, it need not be constrained to local action. And since potencies are brought to act instantaneously, it would seem that this could be a fruitful way to solve the problem posed by action at a distance.
I’ve given some brief arguments that I find to be compelling as of now. With my current limited understanding of physics and metaphysics, it looks like the common-sense appeal, preservation of the PNC, explanation of quantum vacuums, and room for an explanation of nonlocal action are sufficient reasons to prefer the Aristotelian interpretation of quantum mechanics.
Let’s now return to the bullet points listed above and pose a further question: What does Aristotle do for us now that we’ve revived him?
Teleology
Classical mechanics can be formulated in terms of differential equations based on the Newtonian laws of motion, or with integral equations, which relies on the conservation of energy. Early modern philosophers and modern physicists favored the Newtonian model, which is bottom-up and reductionist. The Hamiltonian model is not – it is top-down and teleological. For instance, for the Hamiltonian, the energy of a close-system is not reducible to its parts. Furthermore, the model uses “variational-principles” such as the least-action principle, which is teleological.
Understanding all this isn’t necessary to see why it’s important. What is important is that one must choose between the two models. Prior to the quantum revolution, the Newtonian was preferred because of its simplicity – it just posited fewer components. However, things have changed. With quantum mechanics particles no longer are seen to move in a push/pull “efficient causation” method. Teleology is now back into the mix.
The argument can then be put like this:
1). Newtonian and Hamilitonian mechanics are legitimate interpretations of the world.
2). Quantum mechanics is a true picture of the world.
3). Quantum mechanics can only be made sense of on the Hamiltonian model.
C: Ceteris paribus, we must use the Hamiltonian to make sense of the world.
4). The Hamiltonian model is teleological
C: We must now make sense of the world according to teleology
Even though this is argued for independently of the arguments above, it coincides perfectly well with Aristotelianism. In this sense, the argument can be used to give us a ‘check’ after we accept the Aristotelian interpretation and confirm that we haven’t gone awry – accept the Aristotelian model on the grounds given above, see that the Hamiltonian equations are required for all interpretations, and then see that the Hamiltonian equations don’t violate the Aristotelian interpretation.
The Macroscopic
Quantum particles don’t have any positions or momentum: they simply have the potential to interact with things in the macroscopic world. Now let us pose the following argument:
1). Quantum particles are only potential.
2). What is potential cannot fully constitute the actual
C: Quantum particles cannot fully constitute the actual, i.e., macroscopic world.
How should we see the relation between the two worlds? Since the quanta make up the macroscopic world, how can we say that they are not fully constitutive of it? Yet, since quanta lack any position or momentum, how can they constitute the macro world at all?
In philosophy, we see a problem and posit a potential solution. Here is no different. To solve the paradox let us go back to the ancients – specifically Aristotle. Aristotle deploys the notions of act and potency that line up very well to what is seen in quantum mechanics. As alluded to in the argument, the quanta are merely potential – they exist virtually as some potentiality for interaction. The macroscopic world is what does the actualizing and brings the quanta into actuality. Not only does it seem that Aristotle provides the resources for understanding the quantum and macro worlds, it seems that the macroscopic world has ontological priority over the quantum. In less formal terms, the view of the world on which little atoms were seen to compose everything and humans and dogs are the same substance as rocks is false.
Quantum Chemistry
The Aristotelian interpretation goes a long way in establishing the autonomy of thermodynamics. The world is composed of thermal-chemical substances, and virtual parts. The thermal substances are what we would expect: things with temperature, entropy, and a chemical composition. The virtual parts have quantal properties and are in superpositions.
One may think of the famous Schrodinger Cat mentioned above, which some take to be a violation of the principle of noncontradiction. The reason why this is not a problem for the Aristotelian interpretation is because the cat is a substance with biological and chemical properties that are not themselves in superpositions. The virtual parts are distinct from the cat’s properties, but are in potentiality.
Prior to the quantum revolution, and even seen today in many thinkers, physics is the king of the natural sciences, and biology and chemistry are claimed to be reducible to physics alone. But this is false. Here are two arguments:
1). The quantum world is potential.
2). Many thermal and chemical properties are actual, such as entropy and temperature.
3). The actual cannot be reduced to the potential.
C: The thermal-chemical world cannot be reduced to the quantum world.
Here then we see that once Aristotle is brought back into the mix chemistry cannot be reduced to physics alone.
The Reluctant Philosopher 