Free Agents (II): lower levels of organization and mental states

On the influence of lower levels of organization on the ability to decide freely and on the nature of mental states

Kevin J. Mitchell, in addressing the relationship between the lower levels of organization of matter (atomic and subatomic) and agency and free will, goes back to Epicurus. The Ionian philosopher asserted that it could not be that atoms always followed prefixed paths. He argued, on the contrary, that they must, occasionally, randomly "deviate" from such paths; otherwise, the future would already be written and no real choice could exist. According to the author, more than two millennia later, this swerve was confirmed by discoveries in quantum physics.

My impression is that the majority view in physics is that when matter moves away from subatomic scales and there are a multitude of interacting particles in a system, the quantum properties of those particles dissipate, so that their probabilistic nature is averaged out and the system behaves deterministically. However, some physicists, and with them the author of Free agents, consider that the indeterminacy inherent in subatomic levels can indeed introduce indeterminacy at higher levels. According to these views, the consequence is that the future is open: in fact, that would be what makes it the future.

Moving somewhat higher up the levels of organization, Mitchell attaches great importance to the great variability of cellular processes and the electrical activity of neurons. That variability –noise, in his view­– consists of random fluctuations in the parameters whose variation is the basis for transmitting nerve signals. And that noise would be, according to him, essential to enable flexible behavior. The brain would have evolved to take advantage of the noise of its components to allow the organism to make some decisions on its own. He goes so far as to assert that without this noise, learning would not be possible. Somehow, the author assumes that noise is a purely random phenomenon and that randomness allows the individual to make decisions. I confess to not being able to understand this argument.

On the other hand, the author understands that the inherent indeterminacy of the brain as a physical system implies that the details of the lower levels of organization (atoms and molecules), or even the slightly higher levels associated with the firing of individual neurons, do not determine the next state of the system. This would open the door, according to him, to higher order features exerting causal power in settling the outcome. From this he infers that the system as a whole –the organism as causal agent– is in charge of its own behavior.

The influence of the organism's past, both from the evolutionary history of its lineage –encoded in its genome– and from life experiences –which are somehow stored in memory– is embodied in the very physical structure of the nervous system, which captures the causal influence it exerts and incorporates it for use as criteria to inform future actions.

What emerges is a structure that actively filters and selects patterns of neural activity based on higher-order functionalities and constraints. At some point in evolution our internal models became so abstract and recursive that they gave rise to the emergence of mental experience. The correct way to think of the brain is as a cognitive system, with an architecture that functionally operates on representations of things like beliefs, desires, goals, and intentions. Ultimately, those representations are embodied in models of the world, models of the self in the world, models of potential actions, and models of its potential value.

Are thoughts and other mental states mere epiphenomena of neural processes or do they have the capacity to influence behavior? If they are epiphenomena –manifestations of neural processes without the capacity to guide behavior– the individual's actions would be a consequence of the physicochemical processes that take place in the brain. If, on the contrary, they have their own entity, they would be responsible for that behavior. For Mitchell there is no doubt: the idea that mental states are mere epiphenomena that simply appear in passing, while neural mechanisms do all the real work, could not be further from the truth. And so, he argues that abstract entities such as thoughts and beliefs have (or can have) causal influence on a physical system.

At this point, I feel I should mention, even briefly, Mitchell's assessment of Benjamin Libet's experiments to which I referred in the review of the first part of Sapolsky's book. In those experiments it was shown that we make decisions before we are conscious of having made them, since a signal (‘readiness potential’) can be detected in the brain that informs us of the moment when the encephalic processes involved in the decision in question begin to run. If these experiments were a true reflection of the functioning of the mind as a whole, we should perhaps think of thoughts as epiphenomena, since they would not be involved in decision making.

However, Mitchell considers those experiments to be of little real relevance because, while in the cases where the decision was arbitrary (being of no importance) there is a signal prior to the moment of being conscious of having made it, in the experiments in which the decisions to be made were about matters requiring deliberation, there is no such prior signal. Libet's experiments would confirm, according to him, that neural activity in the brain is not completely deterministic and, secondly, that organisms may choose to take advantage of the inherent randomness to make arbitrary decisions at the right time.

The author also argues that we have some influence in shaping our character, that not everything that has gone before us was beyond our control. He asserts, therefore, that we are partly responsible for our character. This does not mean that there are no constraints that limit us, although he understands that those imposed by circumstances or heredity do not invalidate the ability to decide freely.

Moreover, Mitchell argues that if we were able to choose what we want to do without being subject to any constraints from prior causes or subconscious influences, then on what basis would we decide? If we are not constrained by our own character, or informed by our past experiences, or committed to long-term goals, how do we decide? On a whim? Based on what?

The answers, according to Mitchell, to these questions are based on consideration of the temporal component. Time is an important variable in decisions. You don't make a decision in a temporal vacuum. Therefore, one cannot disregard conditioning factors that have to do with the past and the future. The organism, after all, is not a model of matter, it is a model of interacting processes. What else does it mean to be you if not to think as you think and behave as you behave in a coherent way over time? Following the author’s argument, that continuity of character defines you, defines each of us.

However –and this is one of my reasons why I find Mitchell's thesis unconvincing–, that definition of the self does not invalidate the fact that, if it existed, it would have a physical, chemical and biological substratum whose functioning would be totally conditioned by the conditions prevailing in the immediately preceding instants, and so on and on, backwards in time in an unfinished way.

Note: This the second part of my review. There will be a third and final part.

Title: Free Agents–How Evolution Gave Us Free Will

Author: Kevin J. Mitchell

Ed. by Princeton University Press, 2023.