Despite the success of neuroscience in establishing a wide range of correlations between brain processes and conscious experience, there is at least one question about the relationship between the brain and consciousness that continues to appear unanswerable, even in principle. This is the question of why we have conscious experience at all.
The problem is that there could conceivably be brains that perform all the same sensory and decision-making functions as ours but in which there is no conscious experience. That is, there could be brains that react as though sad but that don’t feel sadness, brains that can discriminate between wavelengths of light but that don’t see red or yellow or blue or any other color, brains that direct their bodies to eat certain foods but that don’t taste them. So why is there nevertheless something that it’s like to be us?
What is more, why do our experiences have the particular qualities that they do? Why does red look red and not blue? Why do rotten eggs smell the way they do, instead of like roses, or ripe strawberries? And how do we know that these things look and smell the same to everyone? What if, when I see the objects that we all call “red,” I experience the color that you experience when you see the objects we all call “blue,” and vice versa?
Some researchers hold on to the hope that, if we just continue to investigate the brain’s physical properties, we will eventually be able to explain why conscious experience exists and why it has the intrinsic qualities it does. But the problem is more intractable than that.
The issue is that physical properties are by their nature relational, dispositional properties. That is, they describe the way that something is related to other things and/or has the disposition to affect or be affected by those other things. Most notably, physical properties describe the way that something affects an outside observer of that thing. But there is something going on in conscious experience that goes beyond how that conscious experience affects people looking at it from the outside. For this reason, the “what it’s like” to be a conscious mind can’t be described in the purely relational, dispositional terms accessible to science. There’s just no way to get there from here.
This explanatory gap is what is now commonly referred to as the “hard problem” of consciousness, thanks to a paper and book written by philosopher of mind David Chalmers some 20 years ago (1995, 1996). The decades since Chalmers’ statement of the problem have seen plenty of solutions proposed (Weisberg n.d.), but none of them has dealt satisfactorily with the core issue outlined above: that no physical property or set of properties can explain what it’s like to be conscious.
There is, however, one elegant solution to the riddle of how to explain the relationship between consciousness and physical properties. Many illustrious philosophers throughout history have held to this view, and if it is rarely considered today, this is likely because it requires such a radical shift in perspective. Nevertheless, if we are ever going to understand consciousness and its relationship to the physical world, I believe this is a shift we are going to have to make.
The key to resolving the hard problem of consciousness lies in the following observation. While physical properties cannot explain consciousness, consciousness is needed to explain physical properties.
As previously noted, physical properties are purely relational/dispositional. They don’t tell us what physical things are in themselves, only how they are related to other things (and how they are disposed to be related to them in the future). However, if all we ever have is relational/dispositional properties—that is, if everything is only defined in terms of other things—then, ultimately, we have defined nothing at all.
It’s as though someone created a very elaborate spreadsheet and carefully defined how the values in every cell would be related to the values in all of the other cells. However, if no one enters a definite value for at least one of these cells, then none of the cells will have values.
In the same way, if the universe is to actually exist, its properties can’t be exclusively relational/dispositional. Something in the universe has to have some kind of quality in and of itself to give all the other relational/dispositional properties any meaning. Something has to get the ball rolling.
That something (at least in our universe) is consciousness.
If we look carefully, we can see that all of the physical properties that science has so carefully measured and cataloged ultimately derive their meaning from the effects they produce on a conscious observer: the person who’s holding the yardstick or looking at the fMRI or gazing at the interference pattern produced by the double-slit experiment. Even the properties of the basic particles of physics derive their meaning from the ways that these particles ultimately affect the conscious observations we make of them. Scientific experiments cannot tell us what a photon or an electron is in itself. Science can only tell us that, when a photon or electron is present, our conscious experience of the equipment detecting these particles will be affected in a certain way. (In fact, a large number of quantum physicists believe that consciousness is even more central to the operation of the physical world than this, but we’ll have to save that for another time!)
Ultimately, the hard problem of consciousness is the result of a category mistake. We have been trying to reduce consciousness to physical properties when it is consciousness that is the more comprehensive category, and it is only in terms of consciousness that physical properties themselves can be understood. For example, it was the great 18th-century philosopher Immanuel Kant who pointed out that, rather than consciousness being located inside of space and time, it is space and time that are themselves part of consciousness (1781).
One can see how our having gotten this basic ontological relationship the wrong way around could be at the root of many of our frustrations in understanding, not only the relationship between consciousness and the physical world, but also the nature of consciousness itself. Recognizing the ontological primacy of consciousness could finally open the door to the kind of research that promises answers to some of our most pressing questions: not just scientific ones, but ethical and existential ones as well. Rather than trying to reduce consciousness to fit into the box of relational/dispositional properties, it is time that we begin to explore it for what it is—and for the answers that studying it on its own terms, in its full splendor and variety, stands to provide.