Neuroscience as Science of Thought?

Nowadays one can often hear that neuroscience can explain everything about a human being. The external physical world interacts with human sensory systems, natural neural nets in the brain get excited and this in turn causes excitation of muscles. Modern science has found nothing else in a human body, hence when we would like to understand us better, neuroscience seems to be the right way to go.

Stephen Hawking has recently stated in his Grand Design that philosophy is dead, this seems to be consistent with above. I am not sure if Stephen Hawking would completely agree that neuroscience can explain mathematics and physics, yet according to him

It is hard to imagine how free will can operate if our behavior is determined by physical law, so it seems that we are no more than biological machines and that free will is just an illusion.”

Thereafter it seems to be logical that neuroscience could be considered as an effective theory to explain thought.

Below I share my personal opinion why in spite of great progress in neuroscience in particular and physics in general, when I would like to reach systematic and orderly thinking, I still stick to philosophy. I will start with Collingwood’s An Essay on Metaphysics, then I will briefly present opinions on consciousness from two authors who know neuroscience from inside. Finally there will be my advice.

R. G. Collingwood was Waynflete Professor of Metaphysical Philosophy in the University of Oxford. He lived in a time (his book An Essay on Metaphysics was published 1940) when metaphysics did not enjoy widespread use among natural science, rather it was assumed to be dead. Collingwood has written his book “to explain what metaphysics is, why it is necessary to the well-being and advancement of knowledge, and how it is to be pursued.” In Part II of his book, he has considered what he has referred to as anti-metaphysics: psychology and positivism. First I will quote a discourse from that time that psychology is a science of thought

p. 102. “‘If you choose to employ the word metaphysics in that way I shall not try to prevent you, although I will remark that your idea of what metaphysicians are doing is a very eccentric one. The point is this. The work which you assign to metaphysics actually belongs to psychology. The inquiry you are desiderating is one which is being actively and profitably pursued by psychologists all over the world. You seem to be unaware of this; not a very creditable state of things for a person who professes to be a student of thought, but a natural consequence of the fact that you live in a University where it is bad form to recognize the existence of anything less than two thousand years old.”

If one replaces psychology by neuroscience, then it is clear that the idea stated at the beginning is not that new. Now there are quotes from Collingwood that explains how one could aim at body of systematic and orderly thinking.

p. 107. “If a mind is something which has opinions what it is trying to do, its possession of these opinions will in certain ways complicate its behavior. An organism unconsciously seeking its own preservation will simply on any given occasion either score another success or score for the first and last time a failure. A mind aiming at the discovery of a truth or the planning of a course of conduct will not only score a success or failure, it will also think of itself as scoring a success or a failure; and since a thought may either true or false its thought on this subject will not necessarily coincide with the facts. Any piece of thinking, theoretical or practical, includes as an integral part of itself the thought of a standard or criterion by reference to which it is judged a successful or unsuccessful piece of thinking. Unlike any kind of bodily or physiological functioning, thought is a self-criticizing activity.”

p. 108. “This demand was recognized by the Greeks; and in their attempts at a science of thought they tried to satisfy it. They constructed a science of theoretical thought called logic and a science of practical thought called ethics. In each case they paid great attention to the task of defining the criteria by reference to which theoretical and practical thought respectively judge of their own success.”

These two quotes show that orderly thinking was already possible at times when people were even not aware about neuroscience. The question would be what neuroscience could add to science of thought.

Quotes from Collingwood above implicitly require consciousness. To this end, let us consider opinions of two neuroscientists expressed in their books on consciousness: Jeffrey Gray Consciousness: Creeping up on the Hard Problem and Max Velmans Understanding Consciousness.

Interestingly enough both scientists in their books do not consider thoughts at all. They find enough internal problems in neuroscience with so called phenomenal consciousness, that is, conscious experience of the world and feelings. It happens that already at this level, modern science cannot explain these phenomena. Let me quote Jeffrey Gray

p.5. “To put this Hard Problem into a preliminary nut-shell: it arises because nothing in our current theoretical models of brain and behavior accounts for the existence of conscious experience, still less for its detailed properties.”

p. 40. “For the very reason that this type of theory building without reference to consciousness has been so successful, there is no reason to include conscious experience in the scientific story at all. It is an embarrassment for this story that consciousness should exist at all. Existing neuroscientific theory gets on very well, thank you, without consciousness, and can in any case offer no explanation for it.”

In his book after having analyzed available theories of consciousness, Jeffrey Gray concluded that in order to explain consciousness, a new scientific theory is required as existing normal science cannot do it. Let me now show you Hard Problem on an example of visual conscious experience.

We take for granted that we live in a three dimension physical world that we visually observe. However according to neuroscience such a picture that we consciously experience is the result of brain processing. A simple experiment: just look in the mirror and you see your image there. Let us now analyze this phenomenon by means of physics that we know.

  1. Photons are reflected by the mirror;
  2. Neurons in retina are excited;
  3. Natural neural nets in the brain starts information processing
  4. You see your image in the mirror that is constructed by the brain

The question immediately follows where in the physical world this image is located. If the brain constructs it, then it should actually be in the brain. It seems to be logical as we know that there is nothing after the mirror. However, to be consistent we should say that not only the image in the mirror is in the brain but rather everything that you see is also in your brain. After all visual information about the external physical world is obtained the same way. Let me repeat the logic

  1. There is a physical world where there is a human being with his brain in the skull.
  2. The visual information about the physical world comes by photons into retina.
  3. Natural neural nets get excited, brain starts information processing.
  4. You visually experience the three dimensional physical world.

Whether photons comes to retina reflecting from the mirror or not, it is unimportant.

The question is the same, where visual reports constructed by the brain are located in the physical world with which we have started in point 1. In the brain or outside of the brain? According to physics that we know everything should be in the brain. Yet, remember that this concerns everything that you consciously observe, so it follows a paradox. A physical world should be outside of the brain. A perceived world should be however in the brain. Hence is the brain in the world or the world in the brain?

Max Velmans in this book offers a new theory (reflexive monism) that visual conscious experience is outside of the brain as we experience it but the question how this happens remains open. Modern science cannot explain it.

Both books nicely show that at present neuroscience does not have a theory of consciousness not speaking about a theory of thought. Thereafter my advice would be as follows. Before we obtain a developed theory of thought from neuroscience, old-fashioned philosophy seems to be more reliable. The nice thing with philosophy is that you will find anything you like. If you like the viewpoint expressed in the beginning, take Daniell Dennett (some call his book Consciousness Explained as Consciousness Denied). However I personally would recommend Collingwood.