The point of view of a scientist: interview with Gerhard Roth
Professor Gerhard Roth, born in 1942 in Marburg (Germany), after studying philosophy, German literature and musicology at German and Italian Universities, graduated in philosophy in 1969: next he studied biology at the University of Münster and at Berkeley in California, taking a second degree in zoology in 1974. Since 1976 he has been a professor of neurobiology (Behavior Physiology Chair) at Bremen University, and from 1988 to 2008 he headed the Institute for research on brain at the same University. In 2008 he founded the Roth Institute for Neuroscience, also in Bremen. Among the various publications he is the author of, his most important work is The Long Evolution of Brain and Mind (Springer, 2013), which explores the development of the nervous system during the evolution of different animal phyla, from invertebrates to vertebrates, up to mammals and humans, and in which the issue of mind and brain correlation is dealt with.
The interviewer, Lorenzo Pieraccini, graduated in philosophy at University of Siena in 2009, with a thesis on Gerhard Roth, the Brain and the Construction of Reality. During his studies he went to Heidelberg for a year to deepen German philosophy. In 2012 he obtained his doctorate, always in Siena, with the thesis Neurobiology and Naturalism - A Philosophical Synthesis, which examines the discoveries and new theories on the mind proposed by neuroscience, and interprets these contents on the basis of a philosophical inquiry into what reality is. His analysis starts from the study of what is today the most widespread theory of reality in science and philosophy, that is scientific realism. Currently Pieraccini is working as a freelance journalist. In 2014 he obtained the long interview below from Professor Roth.
The first question I would like to ask is about your research as a neuroscientist. How important is neuroscientific knowledge today in the study of mind?
Roth: I think we can not make a mind theory without all the data of neurobiology, because speculations can go in any direction, but often the truths are counterintuitive. The characteristics of having a personal experience, the way we think and how we perceive the world, are not the same as those of the processes that occur in the brain. We will never perceive the mechanisms of synchronization or widespread activity, topology, of the cortex, because our personal experience is illusory in this regard. It is part of the common sense to think that there is an instance that thinks, that reasons, that has a certain perception, but then studying the brain one realizes that these activities are all in parallel and distributed. Neuronal activity has a very different form from the conscious activity of the feeling we experience; such experience is in fact an illusion created by our brain.
The existence of the mind as we know it through introspection is therefore misleading. But then why are we talking about the mind and not just about neuronal processes when we try to explain human conscious activity?
On the one hand it can be proved that when we have certain thoughts, certain feelings, there is always a related neuronal substrate in the brain. It is possible that some thought is represented by several neurobiological processes, but there is necessarily a relationship between a mental state and a brain state. If you studied for a long time an individual's brain, eventually you could guess what he thinks and what he sees. If it was done properly, it would be noticed that for every sensation, thought, perception and emotion there is a certain defined neurobiological substrate. So you could identify neurobiological activity with mental activity. On the other hand, from the brain study and its activity alone, that is from the neurobiological aspect and cell behavior, one can not understand the meaning of this activity, which can only be determined after psychological experiments, for example by asking a person what he/she was thinking or feeling during the neurobiological examinations. From the cortex activity alone, one can not determine what that activity means, that meaning is by no means evident. If you instead ask the patient: «Did you see anything?», and he answers for example: «Yes, a red arrow», at that point recording the activity of the cortex, it can be stated that those processes are the equivalent of «seeing a red arrow», but from the neurobiological activity alone one can infer nothing. Above all, one must consider that what is, in the mind, the substrate of consciousness and perception, is not only determined by the activity that can be measured, there is much more. You can measure few things in the synapse activity. Indeed, there is much more. So one can not assert that thinking is nothing but the firing of a certain neuronal population, because that is not true; it is much more complex, and we only have to admit that when neurons interact in a certain way consciousness or thought emerge, and the relationship is always one by one: a state of mind implies a neuronal state, but one can not reduce the experience to neurobiological activity.
As far as consciousness is concerned, you say that the brain produces consciousness and provides evidence of the neurophysiological bases of this production. Can we say that this explains consciousness?
In a certain way, yes. In my recent books, I have reformulated the concept of consciousness up to considering at least ten different types of consciousness, and we can prove how all these forms of consciousness have a well-defined substrate in the brain. On the other hand, however, one can also explain why we need consciousness. For example, without consciousness it would not be possible to realize what we see and read. In addition, verbalization too is based on consciousness. We may have non-conscious perceptions, but we can not account for them through a verbal act. We can not make any report. Every verbal act involves consciousness. It is therefore a form of information processing. Thus it is possible to explain the function of consciousness in the context of natural laws and information processing. There is no mystical aspect in it, though no one can exactly explain how it works. Maybe this can happen in the future...
Anyway, what relationship exists between conscious and unconscious processes? What can we know about our mind and what remains inaccessible to us?
This is a problem of individual development. The centers that produce Es (unconscious processes) develop long before the centers that produce consciousness, which are based on the activity of the cortex. All that a newborn perceives is either unconscious or can not be remembered, can not be stored in memory at a conscious level. Perhaps the newborn may develop conscious processes before he is three years old, but can not remember such processes because his memory is not yet fully developed. Moreover, the activity of the amygdala and the limbic system is unconscious. These systems, by the way, develop much earlier, and then dominate our behavior far more than conscious processes, which develop later and have no major influence on our behavior over those unconscious; in fact 90% of what we do is based on unconscious processes. There is also another important point: many things that were once conscious (they were learned through conscious processes), are no longer conscious now: they are pre-conscious, intuitive. 70% of mental processes occur «out of the cortex», they are unconscious, produced by the limbic system. In addition, in long-term memory we find traces of the things we have learned consciously but that now are «submerged», have become intuitive, automated. All this is important because these processes drive our behavior without we realize it. Very little of our behavior is governed by conscious reason, little, very little, only one percent. So this is the relationship existing between pre-conscious, unconscious, intuitive, and acute consciousness: three years ago I was in Siena and I did many things, I talked to some people and saw certain things, but these experiences are no longer present in detail. Only when I come back to Siena this unconscious memory (of already lived experiences) re-activates, drives me, even though I can not realize (I can not access it in first person) what is driving me. I was with Professor Nannini at a restaurant when I ate something that made me sick, I was almost dead. Now only this memory is consciously present, all the rest (of experiences) guides me but is no more consciously present, at least not in attentive mode (I can not realize that such experiences guide me).
More and more knowledge about brain processes is emerging lately. Many discoveries lead to admit that the Ego does not exist and that it is an illusion, what do you think about it?
Yes, I have worked hard with childhood development psychologists lately, and together we have verified how one can demonstrate the existence of different stages in the development of the child's Ego. For istance, an extremely primitive form is the one that allows children to recognize treir own needs. After developing this capacity, emerges the Ego of self-identification with respect to the mother, then the Ego as agent, that is, the mastery of body's movements; the social Ego and linguistic Ego develop more slowly. It can be shown that the evolution of these forms of Ego is parallel to that of the brain. But the Ego is always a label, an attribute, not a mechanism. For example, when a child does something and hears the mother say such phrases as «you were good», he/she must first learn that when mother says: «I tell you that you...» she refers to herself, then the child must understand that the you is him/herself. This happens in a certain period after which children understand that the you are themselves and then understands (learns the concept) that all that is controlled by their body and mind is their Ego. Actually, however, the Ego is not a substance that controls everything, it is a label, a unifying instance. Then one can say that on the one hand the Ego is an illusion: the illusion that the Ego is above all other mental processes and controls them. On the other hand, however, without the building of the Ego, people could not act. For example, patients who have lost the unifying instance of the Ego are unable to act in the world. My position is that on the one hand the Ego is a brain construction that does not exist in itself as a substance, but at the same time without this compositive principle humans could not act. Likewise, in human society there are constructions, such as human dignity, which do not have a physical reality, but are very important concepts. Illusory concepts can be very important, democracy for example!
Can there be a region in the brain that can be considered the home of the Ego?
Of different Egos! There is, for example, a prefrontal cortex region called the pre-SMA (Supplementary Motor Area) that only activates when we act in accordance with our internal motivations. This area only activates if we feel that our action is driven by a spontaneous and internal body need, and there are no motivations imposed by outside environment. It should be noted that if a patient is electrically stimulated in this region, he/she begins an action and claims to have done so it by their own will. It is evident instead that electrical stimulation has been the cause of such action. It is very complicated to understand the neuronal circuit that determines the reasons that push us, for example, to raise an arm. Either such motivations come from outside, as in the case of the command «raise your arm», or come from inside the body. Only when I realize that such motivations come from my body, thus from myself, I can develop the concept of «acting Ego». That is, I realize that I am the promoter of my actions. This is just an example of how the Ego emerges from the brain, but there are many other types of Ego: the one of perception, of language and of memory, to name a few, and all of these types of Ego, when we become conscious of them, have different localization in the cortex. One can quickly demonstrate, for example, that because of a brain injury, the sense of Ego as an agent can disappear without disturbing perception and intellectual ability; patients with such a lesion have the illusion that some external force drives them. Another example can be provided by studying the ability to recognize ourselves in a mirror. It may happen that some patients get up in the morning and see in the mirror, instead of themselves, a person they do not recognize. This is because the parietal centers that are involved in facial recognition are injured or destroyed, and no one can be recognized, not even ourselves. On the other hand, even though they do not recognize themselves in the mirror, the rest of their Ego is unharmed and when they do something they frankly say, «I'm the one who is doing it», but they can not recognize themselves in the mirror. Then one can perceive how the different Egos are distributed in the cortex when they are conscious, otherwise, if there was only one center of the Ego, there would be an all or nothing; or the Ego is there or it is not there. Instead, as I have shown, it may be that some forms of Ego exist even if others are gone, because their distribution in the cortex is highly differentiated.
Another longstanding problem which neuroscience today deals with is that of free will. It is an even bigger problem than that of the Ego because all people feel they are free...
Not everybody! There are patients who say, «I am not free, a force within me tells me what I must do, I am not free». One might even mention those who are suffering from obsessive impulses: they are forced to do something, like washing hands every five minutes, they must do it! They are forced because of a disease that attacks the basal ganglia. The brain obliges them to act without being able to make a free choice. When we are very thirsty, in any case, we have to drink, we are not free, it can happen that we drink even if the water is dirty and we do not feel free, we are driven by a very strong need. So we can say that feeling free means: there is no external or internal force that controls us, that dominates us, and the absence of these two forces means «being free». These are the preconditions, that's enough. Psychologists who investigate the conditions in which people say, «I feel free ... to attend this meeting or to drink or not to drink a coffee, etc.», simply assume that people are free if no one forces them and they might act otherwise. If, for example, I have tea and coffee in front of me, a free choice, I choose tea instead of coffee and I feel free. If you ask me who decided for tea instead of coffee, I say, «I did it!». Feeling free is enough for people. Actually, studying the human brain one could determine exactly what brain processes have prompted to take tea instead of coffee. You can explain the reasons totally. Then I feel free when I have a choice, but this choice is determined by my genes, by my childhood experience, by my experiences to date, and all these reasons affect me all the time. If you do neurological and psychological studies on people who drink coffee or tea indifferently, you will not be able to tell in advance whether they will choose one or the other. In fact, when the reasons for making a choice are the same, there are no prevalent ones, so it may be that to choose you are even forced to use the die, at random. This means that sometimes the mechanisms of the brain find no strong motivation for one or the other solution. Not always then our brain determines exactly our choices.
Hume said: «We are free, we feel free, when we have a choice»
When we decide something, this event is always determined by our personality. One has to realize that the chance of deciding, the Kantian possibility to decide without impulses, is absurd, does not exist. When Kant wrote, he mostly spoke about morality. Morality is to act against our own interests, against our internal motivations. For example, if I see something very attractive and no one looks at me I might want to steal it, but I do not do it for moral sense. Also helping a friend, or your own wife, is not moral, because it is dictated by feeling. Morality is the conscience of morality. Morality is right in itself, Kant said, but this is absurd! People steal when the chances of not being taken are minimal: only a few do it even at their own risk. Reason, therefore, only comes into play to calculate the chances of success, but the moral being derives from the education received. Morality is based on individual and social experience. For example, I have been educated by my father and my family not to steal even if no one sees me. To become a moral feeling, however, a precept must be repeated many times. It is education. Kant's moral freedom does not exist: morality is education.
For instance, if it happens that you are very angry and you do not kill anyone who has offended you, you have learned to control your impulses, and that has become your nature, or else your brain warned you that you may be taken and put in jail. But if you really lose your control and kill, in court the judge condemns you: «You had the opportunity to resist the temptation, and you did not, you are responsible for your actions», he will say. Actually you could argue that this was not under your control. You are not responsible for your genes and personality that have led you to act in that way. This is a big ethical problem that can not be solved because our criminal law is based on the idea of free will, which does not exist. Or you resist because you have a certain education and certain genes or you do not resist because you have another education. We study young criminals and investigate the reasons they commit crimes and we can argue that 20÷30% of their behavior is influenced by their genes and the rest by education, their family in the first place. They are never free, since this kind of determination occurs in the early years of life when we are not yet fully conscious. Then it affects us for our entire lives.
70÷80% of our personality is formed during childhood. Many studies show that in the development of personality and behavior, genes account for 20÷30%; at least 50% comes from primary experience, since you are a newborn up to three years, then the remaining 20% is determined by adolescent and adult experience. This applies to everyone, for normal people, but also for criminals and patients. We grow up with a personality that is formed very early, of which we have no consciousness. We must admit the idea of being controlled by forces we do not recognize. Everyone has their own personality, but we have no idea where this form comes from. Only after an in-depth study of many years it can be determined whether a trait of personality comes from genes or from early childhood, and so the whole personality can be reconstructed. And that's what we do with young criminals. We use above all psychological techniques: also brain studies, but above all psychological techniques. We make interviews, we investigate the family: absence of a father, doped mother, lack of money, no education, misery. From this we can understand how the personality of these guys evolves, almost in a standard way. To say they had the freedom not to steal does not exist.
Concluded the theme of free will, leaving behind many open questions, as every dialogue has to do, I would like to ask you about a more metaphysical theme, in the sense of reflection on physics, in this case on neurobiology. You tell us that the brain «creates» reality, that what we perceive is not just a representation of reality, but a real building, «Bildung». The reality that the brain creates is full of our memories, our emotions; is a phenomenal world. You call it, «Wirklichkeit». Can you describe it?
This is an idea that has become very common in today's neurobiology, no one has any doubt that it is so. When you visit a place for the first time everything is new, interesting. When you return to the same place a second or a third time, everything is interesting, but not as the first time. If you live in a place for ten years, then you see it completely different from the first time. Even in love is so. You fall in love with a beautiful girl, then if you live with her for ten years you forget the reason why she looked so beautiful! That of the senses is always a selective activity, but we always see the world through our memory. Memory does not reflect the outside world. The same long-term memory always rewrites our experience, every day. It is not a static knowledge, it is a process: if you return to a place where you have already been, this perception is being reformed always in a different way. Then we must recognize that man sees the world more or less identical, but always in relation to the data provided by memory.
The brain sees what it is waiting for. At the beginning, when just born, or before birth, in fact, we are as blind. The brain must make an interpretation of what we see for the first time. This interpretation mechanism that begins with birth, or before birth, and ends only with death, implies as its constituent that whenever a new experience is perceived, its interpretation is updated by modifying or reinforcing certain aspects. Each time the brain creates a new world based on the new experiences. It is a totally internal process. If you know a person for ten years he/she is not the same person that you knew ten years earlier, because in the meantime you have lived a long period of time that has rewritten all the experiences you had memorized. Our great brain perceives what it expects. We see what we are expecting relying on our memory. Often we are aware only of the variations that an experience shows us with respect to the features recorded through memory. If this difference seems very deep, the brain rewrites and modifies the content of the experience, otherwise, if the difference is minimal, the brain sees what it expects to see based on its previous perceptions, and this, at times, is also extremely dangerous. A very common thing comes, for example, from meeting with a friend who has been bearded for ten years and has cut off his beard. When you see him after the change, either you do not perceive any modification, or you see something vague that disturbs you, but you can not realize what. You do not immediately perceive that he no longer has a beard because your brain makes you perceive the world more or less as it expects, and it takes time to rewrite the new information and give rise to a new perceptual experience. This is very dangerous, as I said earlier, if we are driving in traffic on a road that we have been steadily traveling for ten years. It may happen that we do not notice some new signs that signal that that road is now a one way, because our perception is obscured by the habit, by our past experiences: it's like being blind! All this happens because it is very practical for our brain to base our perception on memory and rewrite the data in its possession only in the presence of big differences: it is energy saving!
At this point I have to ask you what is the illusion by which we believe we are in first person the authors of our choices, while instead it is a complex brain-mind system that makes us what we are.
The illusion is that there is an Ego that is the master. If we accept our personality, and the fact that this personality has developed from genes and past experiences, then we accept our own being. Then I can say, «This is me». I am composed of a mosaic of so many things. The ability to change one's personality is limited in adulthood. We have to accept ourselves. We are as we are. So also anxiety disappears. We just have to accept what we are. Our personality is controlled by the unconscious, not just the Freudian one. It is controlled by everything we do not realize, such as intuitions, for instance, and past experiences that are not consciously remembered, but which can be consciously accessed through memory. Our thoughts are also guided by unconscious components that we do not perceive. This must be accepted. Despite everything, there is still a choice! However every choice is within the personality sphere. For example, a friend suggests you go to the cinema and you accept, then you think about it better and say no, but you do not know why. If it finally comes out that you do not want to go to the cinema for fear of being surrounded by people, for example, you become aware of it, but you still do not know why you have this phobia. Despite our awareness, the deep reasons why things are in a certain way and not in another remain hidden to us. And this happens often. We do and say things and we do not know why. If you ask me why I want to stay home despite there being a very nice movie to see, I invent something, for example, that I have to finish a task, but it is not true: in fact, I'm afraid. Often people give very complicated explanations of their behavior because in the deep do not know why they act in that particular way, and so invent, giving superficial reasons. It often happens to me to check this out when I talk about my profession with managers in the German economy. Often they have the need to explain that they are in a certain way; they need to recognize and assert themselves as ambitious and hard workers. It could be all fake, but they need to self-represent a unitary framewotk of their own personality. Only if you accept the aforementioned facts the anxiety of living disappears: you are what you are.
The personality problem is amazing to me. Even more, however, there is a point in your theory that intrigues and upsets me. Exactly when you say that the difference between mind and brain is a difference within the phenomenal world (thus an apparent, not real, difference). Can you explain it better?
As a neurobiologist I explain how the brain produces the mind: I make experiments on the brain. What I see from the experiment is, however, a brain that my brain has created. I see it in front of me, but you can instead show, through another experiment, that is my visual cortex that has created the brain I'm observing. What I do, like my hand when I see it, is a construction of my brain. All I see is a construction of my brain. Through fMRI I can see my brain, which actually is not my brain, but a brain built by my brain. My Ego also is a construction of my brain! All my experience is a construction of my brain. The brain that creates me does not exist in my experience.
No neurologist would doubt that it is so. I see my hand and ask the neurologist where the image I see is formed and he answers: in the brain. I feel something and wonder where it is happening? In the brain, of course! Then the logical conclusion is that there is a real world outside where there are humans, where I also exist (a man called with my name and a brain): this is reality (hopefully)! The world where I exist (as a self-perception) was instead built by that man with that brain and my name, but I will never see it! Everything I see and feel is a brain construction. We have to admit that there is a real world where there are humans and animals with brains that build actual worlds (phenomenal), but for us this actual world is the only world that exists, the only one we can know without being able to see beyond. Even if I study my brain I can not transcend the phenomenal reality because what I see is built by my brain. I can not go beyond this world. Logically too, it is not possible. At this time, as we are speaking, two constructions speak in a mind that brings my name, and when you perceive yourself talking, there is a creature with your name in whose mind the conversation takes place and associates the word I and the word You with our constructs.
How is it possible that two constructions which are in two minds (ours) that are individual, separated, come into contact? How can we have a discussion between us if we are each in the mind of the other?
In my book Bildung braucht Persönlichkeit (Education Needs Personality) I have treated this issue again. Once again I wondered how, if everyone is imprisoned within themselves, it is possible to understand each other. Understanding the other is a result of a long process. We understand each other because we are human beings. This means that we can understand the expression of the face, the gestures, the emotional aspects of others, these are things we understand spontaneously. There is comprehension even without words. Moreover, we can speak the same language, for example Italian. It is worth pointing out that there will always be some differences in the use of language, for example between me and you, because I was educated in Germany and you in Italy. Even after forty years of confrontation with Italians there are always things I do not understand. Between Italians themselves there are differences: two Italians born both in Milan understand each other better than one born in Milan and one in Rome, because they received the same kind of education. It is difficult to understand one another even if we come from different social classes. The more the education is similar and the easier it is to understand each other. This explains how comprehension is not a direct mechanism, from the stimuli of a brain to another. It is your brain that rebuilds the perceived stimuli and, at the same time, each brain rebuilds more or less the same stimuli since the mechanisms that carry out this process are the same.
Even if you live in close contact for years you can never be sure of understanding what is happening in the mind of another. For example, my aunt used to say about my uncle, after he was dead, that he was a good man, but this was actually her construction, because she never understood what was occurring in his mind. So one might argue that understanding is a construction that two brains make in parallel with each other, without however being able to end with a real mutual conprehension and interpenetration. Everyone sees the world according to their experience and if the experiences are very similar, then two people see the world almost likewise, but if the experiences are different the world is seen in a very different way. It is difficult for one coming from the working class to understand one coming from the capitalist class, and if this happens it is because they have a background of common knowledge and experience.
In our contemporary world we talk so much about objectivity, but in light of what has been said so far, how do you answer the question: what is truth?
This is a question I always ask as I carry out my researches. When the world's conception is quite stable, one believes, for example, in the truths of the church, in the Pope's word, in government affirmations, then a concept of truth can be developed. Believing in God, in heaven, in institutions in general, allows you to believe in certain truths. But the world is constantly changing and there is no truth. Every day, each and every one of us makes new and different experiences that make our knowledge continuously renewable. Even in my science (neurobiology) is so. Ten years ago, for example, some experiments led to believe in a certain truth, which, according to new experiments, has been proven to be false. However, after some time, scientists have come back to the first interpretation and assumed that that was the truth and not the other. For example, with regard to intelligence, in England Cyril Burt had experimented with monozygotic twins, discovering that 50% of intelligence comes from hereditary characters. This did not please the community of psychologists of the time, who were happy with the lack of data supporting this thesis, so that even his disciple Hans Eysenck had to deny his teacher's truth. Surprisingly, years later he discovered that Burt was just right! There is nothing to prevent, however, that in the future we may find out that he was really wrong.
Whenever I open a scientific journal, above all, I read that many of the truths we have and the things we think are no longer justified. This is a very common experience among scientists in my field; then what would be the truth? Through which process could we find the truth? The press says the truth, the Pope says the truth, but if I publish a scientific article I can not say, «this is the truth». I can only carry out experiments that are not stupid and, if compared with brain studies of neuroscientific experiences over the last hundred years, are consistent and have plausible results. The truth does not exist because there is no way to find it. Some articles can deny other articles; it can be shown that some experiments have been done badly and that the results are therefore not reliable, but never assert that that is the truth. There are logical truths, but what we are concerned about are empirical truths and these can only be sought through plausibility, coherence and consistency of data.
Truth then is an ongoing process that is always renewed according to new data?
No, you can not even speak about truth. A philosopher might, by absurdity, claim to believe in Thomas Aquinas and reject the claims of science by saying that they are all wrong. We believe that science is incessantly increasing our knowledge, but we do not know it with certainty. (Ironically) It could be a total error, and Thomas or Aristotle or Jesus may have been right. Often my students ask me: Professor Roth, is there a life after life? I answer: I do not know. What I can say is that there is no evidence of the existence of a life, similar to the one we are living now, after death. If there is another life, it can only be totally different from the experience we live on the Earth. We can not know. For example, the dogma of Mary's virginity is an empirically unproven statement: no case of conception without insemination has ever occurred. The church nevertheless continues to support the dogma of virginity, which still stands on a translation mistake. Indeed, in the original text it is written a young woman, not a virgin woman. In the subsequent translations, after the mistake, this translation has been preserved. Every theologian knows this mistake, even the Pope, but despite this they continue to support the illogical dogma of virginity. In any case, this is a truth that is not part of the world investigated by natural sciences, that is, of this world. You could also develop a concept of soul within the natural sciences by identifying it with the psyche, but if you talk of an immortal soul then I wonder what is the empirical evidence which allows to affirm this truth.
After death I know how my body ends, I know how the body's decomposition processes occur, but I have no idea about what happens to my psyche, my thoughts and my memories, in fact these have never even existed as physical entities.
Why not? Of course they existed, they were produced by the brain. Thinking is a physical state. It's a bit strange, but emotions exist physically. If you study under what conditions the brain produces the thoughts, you can describe such processes. Thought, mind, are physical entities. It sounds strange, but there is no doubt about that. This is proved by the fact that when we think intensely our brain consumes more energy, oxygen and sugar. Thoughts, mind, are physical entities because they follow the laws of physics and evolution, and if this machine, the brain, disappears then the mind too disappears in the sense of how we feel it. As a theologian, one can think that the mind is something different, but as a scientist I can only wonder what are the evidences to support such statements. All the evidence is that when the brain dies, the mind too dies. This can also be seen with the decline of the brain in the old age, that corresponds to a deterioration of the mind, such as in Alzheimer's cases and senile dementia, for example. If there was a soul surviving death, it should be a soul that does not exist in our empirical world. I can say, as an agnostic: I do not know. As a philosopher of constructivism I can not say, «God does not exist». It is forbidden. If you wanted to give God an empirical conception, then I could say that God does not exist because there is no evidence of such an entity, but if you give me a non-empirical conception of God, I could just say, «I do not know». To talk about God is to say that there is a planet that has so many interesting aspects but is not perceivable. It therefore depends on the given concept of God, if you want to embrace a constructive point of view.
To conclude, I would like to go back to the concept of «speaking» as an internal brain processing, what is the substrate that allows us to elaborate an interpretation of the intentions of the speaker?
We have a genetic basis to understand human language. This ability develops in the brain's left hemisphere. If I meet a man who speaks a foreign language, even though I do not understand what he says, I know that he is a man and that he is speaking a human language because this possibility of comprehension is genetically determined. If I spend some time with him, I will slowly understand the meanings that he attributes to certain words, until I reach the understanding of his linguistic circle, in an almost spiraling movement.
Realität is instead the physical reality?
No, this can not be said, because if we say that physical reality is the true reality we do not realize that even physics is a construction of our brain. We can only hope that there is a true reality, because otherwise it becomes difficult to explain many things, but it is definitely unknowable. We can not describe the reality because we have to use ours language that derives from our mind and thus from our Wirklichkeit (phenomenal reality). For example, if we say that colors do not really exist, then we must ask what exists? The frequencies of light, we could answer, but what are light and frequencies then? They are physical concepts. They are constructions. We can write a formula to describe the trend of light frequencies, but a formula is an exclusive construction of the mind. There is no way to describe reality regardless of our experience. Even if I reduce physics to mathematical formulas, these formulas need to be learned from a human mind, and it requires a study of many years. It's a construction I do for myself, even though I think the world follows these natural laws. We must realize that the concept of natural law is also a a built concept.
However this construction, let's be careful, is not an invention, because in natural sciences we have developed a method that maximizes the plausibility of statements. If someone said to have seen Jesus, I would ask him how he realized that he was really Jesus, and if he replied that he could feel it, I could not but ask him to give me a clear proof of what he claims, that proof that in science is required to justify every statement. Science, however, has nothing to do with the truth, but only with degrees of plausibility. No physicist I know would say that the description of the world of physics is identical to reality. No physicist can explain the reason of causality, no physicist can explain why gravitation exists. How can we say that physics is the reality, if the basis of physics is not known? Nobody knows if this world is extended, no one knows if light travels: it is not understood how unsubstantial light has a speed, albeit great. There are Einstein's paradoxes for which the speed of light is not additive. There is probably no speed, it seems to exist only when we measure it. No one can explain whether the light is corpuscular or a wave. Certain experiments assume light is a wave, others it is made of particles. This is not truth. This is not reality.
There is only the world of people: konsensuelle Bereichs...
Yes, sure. The consensual world tells us that sometimes there are particles and sometimes waves. Sometimes it tells us that light travels, that has a speed. On the other hand, there are Einstein's paradoxes, quantum mechanics are full of paradoxes.
Reality is full of paradoxes!
My comment (November 2023): After reading again this interesting interview with prof. Roth (died in April 2023), I would like to highlight two particularly important aspects of his elaborations on the topics covered. The first is that sometimes his interpretations of the data obtained from the experiences on the brain functioning are affected by his scientific education, which leads him to objectify the results of observations and experiments conducted on individual organisms and individual brain organs: Roth seems to want to reach the conclusion – in my opinion hasty – that what can be found in a single brain regarding the relationship between the functioning of the brain and the mental experiences that derive from it, must then be valid for any individual. But the fact remains that the vast range of experiences induced by the psyche suggests that also the opposite can happen, that is, phenomena of mental origin can influence the brain functioning: in fact, from an anatomical and physiological perspective, human brains are not very different from each other, while the experiences determined by the psyche can lead to enormous differences between the way of feeling and behaving of one person and that of another person. The second aspect is that Roth's philosophical and cognitive orientation leads him to be well aware of the problems that must be faced when it comes to interpreting reality in light of one's own mental dynamics (which may show subjective differences between one person and another), to the point of making him deny the very possibility that human mind can arrive at the ascertainment of permanent and indisputable truths, except those intrinsically consistent (and metaphysical) of logic. And this is especially true with regards to knowledge on the correlation between brain functioning and mental activity, which should always be considered as two aspects of the same phenomenon.