Physics and Freedom

“Scientists, animated by the purpose of proving they are purposeless, constitute an interesting subject for study.”

-Alfred North Whitehead, The Function of Reason

I’m a frequent reader of the theoretical physicist Sabine Hossenfelder‘s blog Backreaction. She has helped me better understand many difficult concepts in contemporary theoretical physics. I’ve benefited in particular from the times she has weighed in on intra-disciplinary feuds with other physicists about, for example, the proper role of mathematical speculation in the formation of physical theory.

Every so often, she swerves out of the physics lane and into philosophy. Her recent post “How to live without free will” is a good example. I wanted to share a few critical reflections in response.

My usual response to these sorts of arguments from scientific materialists is to remind them that their denials of freedom are blatant performative self-contradictions. I am not finally a Kantian transcendentalist, but nonetheless, I find that Kant’s critical epistemology is the best place to begin a reply to naive materialism. In short, physics is in the business of building and testing mathematical models of natural processes. Currently there are two very successful models in physics, relativity theory and quantum theory. Unfortunately, these models describe two very different universes. Many physicists are working on a grand unifying theory that would bring these models together, but so far, we only have some interesting but untestable conjectures. The relevant point here is that these models always presuppose a mind capable of empirically observing data and theoretically reflecting upon possible explanations of that data. In other words, by dismissing free will and by proxy consciousness, Hossenfelder is forgetting about the transcendental conditions that make physical science and knowledge of nature possible in the first place.

That’s my short critical response. Now I’ll reply more fully to specific points raised in her blog post. She writes:

“Physics deals with the most fundamental laws of nature, those from which everything else derives.”

There’s certainly nothing out of the ordinary about a physicist claiming all of nature can be derived from the fundamental laws of physics. This is standard reductionism. Unfortunately, there is nothing in these laws that entails the emergence of biology, much less psychology or the conscious self-reflection necessary for something like physical science to be possible. So at best the claim that everything else derives from the laws of physics as currently understood is an IOU. At worst, it is an example of scientistic hubris dramatically overstepping the bounds of actual scientific knowledge. The theoretical biologist Robert Rosen argues rather convincingly that the non-entailment of biology by the laws of physics is a very strong indication that current physics is woefully incomplete. In his terms, mechanistic physics is too specific to account for the more generic processes of self-organization intrinsic to the biological world (I’ve written more about Rosen’s perspective here).

I agree with Hossenfelder that quantum indeterminacy is not evidence for conscious free will. The only evidence we would ever have for conscious free will would come from our consciousness of it. For most scientific materialists, this “self-evidence” of free will is easily dismissed as a subjective illusion. Objective physical laws just don’t leave any room for it. From a Kantian transcendental point of view, however, this puts the cart before the horse. Kant asks: What are the epistemological pre-conditions of something like “objective physical laws”? His answer: a rational mind capable of organizing experience in terms of categories like causation and forms of intuition like space and time. Physicists know nature in rational, mathematical, and empirical terms. Rationality, including mathematical reasoning, pre-supposes that a mind exists to do the reasoning. Or is Hossenfelder suggesting that mathematical reasoning just happens in a mechanical way, that physicists play no conscious role in devising and testing their favored theories? Now, I’m perfectly well aware that 20th century discoveries like Einstein’s theory of relativity have forced us to reconsider some of Kant’s a priori framework, but even so, the transcendental challenge to naive materialism remains just as strong as ever.

I don’t know of any philosophers who argue that human beings have total freedom. Even in our thoughts we are restricted by factors beyond our control (unconscious influences, environmental distractions, exhaustion, mind-altering chemicals, etc.). All “free will” means is that we are among a class of intelligent and creative organisms capable of exercising our desires in an effort to help shape the unfolding of future events in some limited way. Denying this plainly evident fact leads us into all sorts of performative self-contradictions.

The most common form of denial that I encounter is to insist that reductionism must be wrong. But we have countless experiments that document humans are made of particles, and that these particles obey our equations. This means that also humans, as collections of those particles, obey these equations. If you try to make room for free will by claiming humans obey other equations (or maybe no equation at all), you are implicitly claiming that particle physics is wrong. And in this case, sorry, I cannot take you seriously.

I’ve written a lot about Alfred North Whitehead on this blog. Anyone familiar with his process-relational ontology will know that it is possible to accept the standard model of particle physics and the obvious facts of human life at the same time. The trick is to free ourselves of the muddled thinking inherited from classical physics (especially the fallacy of simple location and the idea of nature-at-an-instant). Yes, humans are collections of particles (or societies of actual occasions, in Whitehead’s terms). But neither particles nor humans “obey” equations, as though abstract mathematical objects are like chariot drivers whipping us to conform to their eternal will. Natural processes display certain regular mathematical patterns. For Whiteheadians like me, these patterns are more like habits than laws. Some are more regular than others. For example, physics can predict with a very high degree of accuracy how physical particles will behave under certain controlled conditions (even here, there are always anomalies, but in general the laws hold). But physicists cannot predict even in principle how a paramecium will navigate through its environment (there are some regularities, e.g., it will swim toward food and away from toxins or predators, but exact movements cannot be mapped out in advance). This is because as we move up the scale of nature’s complexity, physical processes self-organize so as to be capable of ingressing a greater degree (and a richer quality) of novelty. Contrary to reductionist dogma, biological processes are not reducible to physical processes. Biology remains fully compatible with physics, but nothing in physics suggests anything like biology (or like consciousness!) should be possible.

After marshaling a number of arguments against free will, Hossenfelder draws her post to a close by saying we still make decisions and we should be smart about them:

You are here to gather information, process it, and come to decisions that may, or may not result in actions. Your actions, and the information you share, will then affect the decisions and actions of others. These decisions are determined by the structure of your brain and the information you obtain. Rather than despairing over the impossibility of changing either, decide to be more careful which information you seek out, analyze, and pass on. Instead of thinking about influencing the future, ask yourself what you have learned, eg, from reading this. You may not have free will, but you still make decisions. You cannot not make decisions. You may as well be smart about it.

Am I just confused or are there not numerous performative self-contradictions on display here? We are asked not to despair over the fact that we are determined, as if we had any choice in whether to despair or not. We are told to be “smart” about our paradoxically non-free decisions. Huh? At least she ends her post by admitting that consciousness remains a mystery to natural science. Given this admission, I am left wondering why she felt so confident in her dismissals of freedom.

This is the sort of muddle-headedness that scientific materialism gets us into. Whitehead called these attempts “heroic feats of explaining away.” The implied moral stance of the scientific materialist is that they are mature adults who are strong enough to accept the bleak truth of our purposelessness, while the rest of us are stuck in the past clutching at childish illusions that make us feel safe. I would counter by pointing out that the true nature of our human freedom is far from safe. We do not have freedom, freedom has us. Freedom is far more of an ego-crucifying burden than modern secular liberal political theory would have us believe.