Consciousness is the ultimate hard problem of philosophy of science. As of today, there is absolutely no scientific solution to the problem. The nature of consciousness seems ineffable: first person experience appears to be a completely different category of existence than objective external
description.

This dilemma has led philosophers such as Daniel Dennett to use the ultimate solution: deny the problem exists. Unfortunately, that solution never worked for me at school. The objective reality of bad grades is quite hard to deny.

Yet, we need not resort to Daniel Dennett’s ultimate solution. There are concrete things we can say about consciousness if we use the “many worlds” interpretation of quantum physics and the computer science concept of Kolmogorov complexity.

Quantum physics arises from the fact that when we do not observe a particle, it can be in two different places at once, such that it interacts with itself. This result came from the famous double slit experiment.

Researchers discovered that when they fired a particle at two slits, and observed the particle, it would only go through a single slit. Mysteriously, when they did not observe the particle, it went through both slits and interfered with itself, generating an interference pattern on the screen.

Such strange results have led some scientists propose the even stranger theory: The reason why the particle exists in two states at once is because at that point in time there are two universes in existence. In fact, some believe that whenever there is a quantum event such that a particle must be in two different states, then the universe splits in two. And as a consequence, whenever we are faced with a choice, we actually pick both options. In other words, we can have our cake and eat it too. At least, according to the many worlds interpretation.

Whether such a theory is true or not, we can use it in a thought experiment to probe the nature of consciousness. In particular, we can place consciousness somewhere on the continuum from simplicity to complexity. We can determine whether it lies at one of the extremes or somewhere in the middle.

Let us begin at the simple end. The simplicity of a phenomenon is proportional to how concisely it can be described. It turns out that the phenomenon of describing all the possible worlds is extremely simple. This is because each possible world is a particular sequence of quantum states. We can write this as a sequence of variables: x0, x1, x2, x3, …, xN. Each x variable takes on the value of either 0 or 1. To then list all the possible worlds is a simple matter of writing out every possible sequence of 0/1 values, which can be done with a simple program. As a result, the set of all the possible worlds is a very simple phenomenon, since it can be described with a simple program.

However, we are not conscious of all these possible worlds at once. We are only conscious of a single world.

So, our particular consciousness is not the result of all possible worlds. It is consequently not at the simple end of the simple/complex continuum. Is consciousness at the complex end?

On first glance, our consciousness seems to be at the complex end. As stated, our consciousness lies within just one of the possible worlds, it corresponds to one of the 0/1 sequences. Most of these sequences are random, which we know from Kolmogorov complexity. Thus, if we were to pick one of the possible worlds at random, we would get a random sequence. Maximal complexity is achieved when we reach maximal randomness, and consequently, the randomly picked world is maximally complex.

Yet, while our conscious experience of the world is indeed complex, it is not random. We experience cause and effect, and the physical laws of our universe. The decisions we make, while not always perfectly reasonable, are also not perfectly random (usually).

We make decisions based on reasons and intentions, which correspond to an external reality. I press the brakes at a red light. I eat food to avoid going hungry. I wear a hat to keep my head warm and fashionable. This means the particular world in which our consciousness exists is not just any old random world, but one where the internal experience of our consciousness matches the external reality of the physical world. This means our consciousness does not lie at the purely complex and random end of the continuum. Our consciousness lies somewhere in the middle.

The middle is hard to define, but it is partly described by the match between internal experience and external reality. Only a very small portion of the middle has this well matched property. There are many worlds where the consciousness quantum states are uncorrelated with the external reality quantum states. At any given universe split point (recall our previous discussion of many worlds), according to the theory, one of the forks in the road may lead to a more correlated world, and the other fork may lead to a less correlated world. Based on Kolmogorov complexity, most of the forks lead to less correlated worlds.

Our conscious experience is characterized by this well-matched property. If our experience were to suddenly become random and unrelated to anything, as happens if we are hit in the head, then we lose consciousness. This means that being conscious consists of walking a very tight road between simplicity and complexity, characterizeable by the quantum physics multiple worlds hypothesis and Kolmogorov’s notion of complexity in computer science. So, contra Dennett and others who doubt their own conscious ability to doubt, we can indeed describe consciousness with scientific rigor.

Tune in next time for the close connection between our scientific theory of consciousness and intelligent design theory!

You may also enjoy this piece by Eric Holloway:

Did GPT-3 really write that essay without human help? Fortunately, there’s a way we can tell when the editors did the program’s thinking for it.

Also: Philosopher: Consciousness is not a problem. Dualism is!