Explaining how something as complicated as consciousness can arise from a gray, jelly-like tissue in the head is arguably the greatest scientific challenge of our time. The brain is an extremely complex complex organ made up of nearly 100 billion cells – known as neurons – each linked to 10,000 others, providing about 10 trillion nerve connections.
We have made a lot of progress in understanding brain activity and how it contributes to human behavior. But what no one has so far been able to explain is how all this results in feelings, feelings and experiences. How does the transmission of electrical and chemical signals between nerve cells lead to a feeling of pain or an experience of red?
During much of the 20th century there was a great taboo against asking the mysterious inner world of consciousness – it was not considered an appropriate subject for "serious science." Things have changed a lot, and there is now a broad consensus that the problem of consciousness is a serious scientific issue. But many consciousness researchers underestimate the depth of the challenge and believe that we only need to continue investigating the physical structures of the brain to find out how they produce consciousness.
However, the problem of consciousness is radically different from any other scientific problem. One reason is that consciousness is unobserved. You can't look into someone's head and see their feelings and experiences. If we were to just get rid of what we can observe from a third person perspective, we would have no reason to pose consciousness at all.
Of course, scientists are used to dealing with unnoticeable things. For example, electrons are too small to see them. But scientists post unobtrusive devices to explain what we observe, such as lightning or steam traces in cloud chambers. But in the unique case of consciousness, what is to be explained cannot be observed. We know that consciousness is not through experimentation but through our immediate awareness of our feelings and experiences.
So how can science ever explain it? When we are dealing with observational data, we can do experiments to test whether what we are observing is in line with what the theory predicts. But when we are dealing with the unobservable consciousness tasks, this method breaks down. The best thing researchers can do is to correlate unsupervised experiences with observable processes by scanning people's brains and relying on their reports on their private conscious experiences.
For example, with this method we can establish that the invisible feeling of hunger is correlated with visible activity in the hypothalamus of the brain. But the accumulation of such correlations does not correspond to a theory of consciousness. What we ultimately want is to explain why conscious experiences are related to brain activity. Why is it that such an activity in the hypothalamus brings with it a feeling of hunger?
Indeed, we should not be surprised that our standard scientific method struggles to deal with consciousness. As I explore in my new book, Galileo's Error: Foundations for a New Science of Consciousness, modern science was explicitly designed to exclude consciousness.
Before the "father of modern science" Galileo Galilei scientists believed that the physical world was full of qualities, such as colors and scents. But Galileo wanted a purely quantitative science of the physical world, and he therefore suggested that these properties were not really in the physical world but in the consciousness, which he prescribed to be outside the realm of science.
This worldview forms the background for science to this day. And as long as we work within it, the best thing we can do is establish correlations between the quantitative brain processes we can see and the qualitative experiences we can't, but ways to explain why they go together.
Mind is a question
I think there is a way forward, a strategy that originated in the work of the 1920s by the philosopher Bertrand Russell and the researcher Arthur Eddington . Their point of departure was that physical science does not really tell what matter is.
This may seem bizarre, but it turns out that physics is limited to telling about the behavior of matter . For example, matter has mass and charge, properties that are completely characterized by behavior – attraction, rejection and resistance to acceleration. Physics tells us nothing about what philosophers like to call "the inner nature of matter", how matter is in itself.
It turns out that there is a huge hole in our scientific worldview – physics leaves us completely in the dark about what really is. Russell and Eddington's suggestion was to fill that gap with consciousness.
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The result is a kind of " panpsychism " – an old notion that consciousness is a fundamental and ubiquitous presence in the physical world. But "new wave" of panpsychism lacks the mysterious connotations of earlier forms of the view. There is only matter – nothing spiritual or supernatural – but matter can be described from two perspectives. Physical science describes matter "from the outside", in terms of its behavior, but matter "from the inside" consists of forms of consciousness.
This means that the mind is matter, and that even elementary particles exhibit incredibly basic forms of consciousness. Think about this before you write it off. Consciousness can vary in complexity . We have good reason to think that the conscious experiences of a horse are much less complex than those of a human, and that the conscious experiences of a rabbit are less sophisticated than a horse. When organisms become easier, there may be a point where consciousness is suddenly shut off – but it is also possible that it only fades but never completely disappears, which means that even an electron has a small element of consciousness.
What panpsychism offers us is a simple, elegant way to integrate consciousness into our scientific worldview. Strictly speaking, it cannot be tested; the unobservable nature of consciousness means that any theory of consciousness that goes beyond just correlations is not strictly testable. But I think it can be justified by a form of conclusions about the best explanation: panpsychism is the simplest theory about how consciousness fits into our scientific story.
While our current scientific strategy offers no theory at all – only correlations – the traditional alternative of claiming that consciousness is in the soul leads to a neglected image of nature where mind and body are distinct. Panpsychism avoids both of these extremes, which is why some of our leading neuroscientists now embrace it as the best framework for building a science of consciousness.
I am optimistic that one day we will have a science of consciousness, but it will not be science as we know it today. Nothing less than a revolution is required, and it is already on its way.
This article was originally published on The Conversation. The publication contributed the article to Live Science Expert Voices: Op-Ed & Insights .