Is it possible to reconcile determinism with free will

Wolf Singer is one of the most prominent natural scientists in Germany who deny people free will. For some time now, the philosopher Jürgen Habermas has been an eloquent critic of Singer and other neuroscientists and warns against accepting their image of man.

Habermas sees the basis of coexistence endangered by a naturalism that "reduces everything understandable and experienced to the observable". There would be no more discourse if everyone only understood "what has long been established in the regions of the brain that are remote from consciousness". At, Wolf Singer answers the philosopher's allegations. Jürgen Habermas fears that the world would remain silent and rigid if your image of man prevailed. Is that so?

Singer: The proof that this is not the case is the cultural evolution itself. It began only a few thousand years ago and thus extends over a period of time within which our brains can no longer have changed on a large scale. And our brains function according to deterministic laws of nature. But deterministic systems are also open and creative and can bring new things to the world. That can matter. You have to trust the subject a little more. For reductionists like you, according to Habermas, conscious life just has to be a by-product of the physical brain processes.

Singer: Not at all. Consciousness is an emergent property of brain processes and not a side effect, but something very essential. It has developed in the course of evolution and has achieved a very high value in human brain dialogues. It has a central function. Habermas presents your position differently.

Singer: Then he misunderstood me. In my writings, I have indicated for years that evolution has produced brain architectures that contain knowledge about the world and programs that manage that knowledge. They have adapted to the conditions in which we humans live through trial, error, and selection. Evolution is itself a cognitive process. If Habermas now postulates that we have to "understand natural evolution itself in a non-metaphorical way as a learning process" - he is simply repeating what has long been common property for neuro- and evolutionary biologists. So your positions aren't all that different?

Singer: What Habermas says about the intentional relationship to the world, the mutual adoption of perspectives, the intersubjectivity of understanding - that is in line with neurobiological positions. All of these are emergent properties of the dialogue between mutually reflecting brains. It is social realities that shape our socio-cultural ways of life. But to be effective, all of these processes must of course manifest themselves physically in the individual brain. If we also assume something immaterial, spiritual, which precedes the neural processes and affects the material, then we have a problem with the laws of conservation of energy. That would turn all of physics on its head. Habermas is not the only philosopher who criticizes reductionism and its image of man.

Singer: I think the difficulties with reductionism or determinism stem from the fact that many associate it with concepts from the positivist classical physics of the 19th century. You are thinking of linear processes in which everything runs like clockwork. Then nothing new would actually come into the world. But it is not like that. Our brains are complex, self-organizing, non-linear systems that also interact with each other. This knowledge does not affect our image of man at all. On the contrary. It's wonderful how these complicated processes interlock. In order to talk about something, you have to clarify what you are talking about. That is why Habermas tried to define the term freedom of action: accordingly, actions would be free if you let yourself be determined by insight. Then one can consider - that is, act freely. What does the brain researcher say about it?

Singer: Decisions would therefore be free if they were made on the platform of consciousness, namely by weighing up arguments, with the weighing up to take place according to rational discourse rules. Arguments that can be made conscious are exclusively content that is stored in declarative memory (conscious memory for facts and events, i.e., acquired sociocultural knowledge).

In order to be free, this deliberate process of weighing up should also take place without any external or internal constraints, unrestricted by an overpowering drive structure or a consciousness clouded by drugs or brain injuries. If these conditions are met, the decision is given the attribute freely, and the agent is made fully responsible for his or her action. This decision is then called free. But in your opinion, my self is not really free to consciously decide on a certain alternative course of action?

Singer: Where does conscious deliberation take place? In the cerebral cortex. And who is thinking? Complex neural networks that are distributed over the cerebral cortex and in which there are genetic specifications and rules imprinted by experience. The network states are influenced by knowledge that is recalled from memory and by arguments that one may have just heard, as well as by intermediate results of the weighing process that are in short-term memory. But all of this is based on neuronal excitation patterns that scramble for the most coherent (coherent, coherent) state possible. We become aware of a more or less large part of this process. The fact that this process has to adhere to the laws of nature means that it has to be determined by itself. How does an ego-consciousness come into play?

Singer: For this, it is very likely that the interaction between brains is required, which must have very specific cognitive abilities. One of these skills is the ability to take on perspective: we can imagine what is going on in someone else's head. We even see ourselves mirrored in the other's perception. Such processes require the ability to build a theory of mind. Then we are able to achieve high levels of abstraction, to symbolically code and to communicate these codes.

All of these were prerequisites for cultural evolution, the achievements of which then led to the refinement of brain functions through education and cultural imprinting. It is also a cultural achievement that we can build up complex logical constructs of a higher order and use them to weigh things up. However, we have no feeling for the deterministic neural processes that underlie all these services, and we have no insight into the vast number of determinants.

This leads to the fact that we ascribe to others and ourselves to be autonomous, self-determined, freely acting individuals at all times. This actually sounds very similar to Habermass's idea of ​​the "objective mind", which emerged from the interaction of the brains of animals that are capable of perspective, and the "subjective mind" that is formed in the course of a socialization of their cognition.

Singer: But Habermas always seems to fall back into this "world of reasons and arguments" that has something immaterial about it. As I said, if reasons preceded neural processes and were not first implemented neural in order to have an effect, then this radically called into question the scientific worldview. So you do not deny people an "I" and a "consciousness". But once again about freedom of action: In everyday psychology, healthy people are given the ability to freely choose from several alternatives.

Singer: This definition is also used in case law. But I have my problem there. Arguments must be available for decisions that are reached through balancing. But you cannot consciously fetch anything from your memory - even if it is there. What comes into consciousness of the much known depends on many unconscious motives.

It is unlikely that a person with a strong instinctual structure would come up with the arguments at the decisive moment that prevent him from doing what he would like to do because of his instinct structure. And if a forensic expert finds a tumor in certain areas of the frontal lobe of a criminal, then it can be argued that the person could not suppress the crime because the necessary control centers have been destroyed.

But we know that such defects do not always have to be visible. Nerve tracts can be genetically missing or weak due to developmental processes, or the synapses are not strong enough because the person concerned has not learned properly. There are many possibilities that we cannot grasp right now. But once you admit that everything we do is based on neural processes, then you have to assume that the perpetrator - unlike other people - was unable to activate the inhibiting mechanisms that would have allowed him Suppress deed. This applies to people with brain defects. But the decision-making processes always take place in structures that were primarily formed during our socialization, under the influence of experience and learning processes, and on the basis of our biological makeup. If, as a sane person, I make a decision at a certain moment, am I just at the end of a causal chain that determines this decision? And the only reason you can't predict what I'll do is because you don't have enough information?

Singer: Even if you had all the information, you could only make probability statements because the dynamics of the system are highly non-linear. But can one now say that as a sane person I could have decided at that moment to act differently?

Singer: Probably not. All of these specifications determine what happens next in the brain from a certain state. The fact that some of these factors penetrate our consciousness and that we perceive our decisions to be freely chosen does not mean that the neural processes do not obey a deterministic mechanism.