The Illusion of a Boundary: Life, Consciousness and the Self

I have no particular scientific or philosophical justification for believing this, but I have increasingly found myself comfortable with a simple possibility: perhaps the universe just exists. There may be no ultimate reason for it, no mission it is trying to fulfil, and no purpose towards which everything is moving. The same may be true of what we call the laws of the universe. They may simply be our way of describing what reality does.

As humans, we seem to be uncomfortable with things having no reason. When we encounter something sufficiently complicated, our instinct is to ask why it exists, what it is for, and what lies underneath it. This instinct is extremely useful. It is probably one of the reasons we have science in the first place. But I am not sure that the fact that we can keep asking why means that reality owes us an answer at every level.

I often think about life as an analogy.

At some point on the early Earth there were inorganic atoms and molecules. Under certain conditions, increasingly complicated chemistry occurred, eventually leading to self-replicating systems and, over an enormous amount of time, to cells and organisms. From there came increasingly complex life, nervous systems, brains and eventually us.

Now look at what exists at our scale. We have entire fields devoted to understanding cells, organs, diseases, cancer, autophagy, ageing, genetics and thousands of other phenomena. These are real and useful concepts. Understanding them saves lives. But none of this means that “autophagy,” for example, was sitting somewhere among the fundamental ingredients of the early universe waiting to appear. It is a name we have given to a particular process that becomes meaningful at a particular level of biological organization.

I wonder whether something similar happens much more broadly in the way we understand reality.

Going downward

Suppose we start with biology and keep asking what lies underneath it. Biology becomes chemistry. Chemistry becomes interactions between atoms and molecules. Atoms take us into quantum mechanics and quantum field theory. Perhaps our present theories themselves emerge from something deeper that we have not discovered yet.

We can keep going down conceptually:\[ \text{life} \rightarrow \text{chemistry} \rightarrow \text{atoms} \rightarrow \text{particles and fields} \rightarrow \text{?} \]

Maybe there are many more layers beneath what we currently consider fundamental.

But I suspect that if we could somehow continue all the way down, eventually we would arrive at something for which there simply isn’t another explanation. Something exists, or something happens, because that is simply how reality is.

We sometimes use ideas such as fluctuations and symmetry breaking to explain how one state can arise from another. But these don’t ultimately solve this problem. A fluctuation requires something capable of fluctuating. A symmetry-breaking process requires some underlying structure and dynamics. We can always ask why those exist.

Eventually either this chain continues forever or we reach something that simply is.

I am quite comfortable with the second possibility.

This is also how I tend to think about the laws of physics. The universe does what it does, and we observe regularities in its behaviour. We construct mathematical models that describe those regularities remarkably well, and we call them laws.

This does not mean the regularities are imaginary. Clearly they are not. But our descriptions of them are human constructions and can change.

Newton’s theory of gravity described nature extraordinarily well within its domain. General relativity gave us a very different and deeper description. The planets did not change their behaviour when Einstein published his theory. What changed was our model of what they had been doing all along.

Perhaps, then, there is an important distinction between reality behaving consistently and the laws through which humans describe that consistency.

Now go in the other direction

Instead of reducing things, suppose we start from simple physical systems and move upward.

Atoms form molecules. Molecules form increasingly complicated structures. Some chemical systems eventually become capable of replication. Cells appear. Multicellular organisms emerge. Nervous systems develop. Brains become increasingly sophisticated.

As this happens, new words become useful.

At some stage we call something life. We distinguish organisms into species. Much later we talk about intelligence, memory, emotion, self and consciousness.

This does not make these concepts useless or unreal. Quite the opposite. They are useful precisely because describing a human being as an arrangement of elementary particles would tell us almost nothing useful about being human.

But usefulness at one scale does not necessarily make something fundamental to reality.

Species are a nice example. Evolution is continuous. If we could line up every generation connecting some ancient ancestor to a modern organism, neighbouring generations would be almost indistinguishable. There was not necessarily one magical birth at which one species suddenly stopped existing and another appeared.

After enough evolutionary change has accumulated, however, the organisms at distant points in that chain can be sufficiently different that giving them different names becomes extremely useful.

The categories are meaningful. The underlying process remains continuous.

I think something similar may be happening with life and consciousness.

Where exactly does consciousness begin?

This is where I find a little test useful whenever I get confused about these questions: I try to find the boundary.

Start with us and move backward through evolution.

Modern humans came from earlier humans, which came from earlier hominins, then earlier primates, mammals, vertebrates and increasingly simpler organisms. Keep going and eventually we reach organisms with very primitive nervous systems, then life without anything resembling a brain, and eventually the boundary between biology and prebiotic chemistry itself becomes difficult to define.

At what exact point in this continuous history did consciousness appear?

Was there an organism whose parents were unconscious but which suddenly became conscious?

That seems strange to me.

A more natural picture, at least to my mind, is that capacities accumulated gradually. Organisms became better at sensing their environment. Nervous systems became capable of integrating more information. Memory became more sophisticated. Brains developed increasingly elaborate representations of the world, their bodies and eventually aspects of their own internal states.

After enough of these capacities accumulated, the resulting phenomenon became sufficiently distinctive that we gave it a name: consciousness.

That doesn’t mean consciousness is meaningless. It means I don’t see a reason to introduce consciousness as an additional fundamental ingredient of reality.

This is similar to saying that a person is running. There isn’t a separate substance called “running” that enters the body. Muscles contract, limbs move, the nervous system coordinates them, forces act between the feet and the ground, and the whole organized system behaves in a way for which running is the useful description.

Consciousness may be enormously more complicated, but I suspect the conceptual situation is similar.

But why does it feel like something?

This is usually where the question becomes more difficult.

I see red. I feel pain. I remember yesterday. I know that I am thinking right now. These experiences seem qualitatively different from simply saying that neurons are processing signals.

But I am not convinced that we need to put another entity between the processing and the experience.

When I see something red, the outside world does not send “redness” into my mind. Physical signals reach my sensory system and are converted into neural signals. Those signals are processed by a brain shaped by biology, development, memories and previous experiences. What I experience is the result of this enormous integrated process.

A digital photograph provides a crude analogy. At one level it is an array of numerical values. Looking at one number tells you almost nothing about the image. But once millions of values are arranged and interpreted together, we see a face, a mountain or a sunset. The meaningful thing appears at the scale of the whole representation.

The brain is vastly more complicated than this. It doesn’t merely process incoming information. It has memory. It compares present signals with previous experience. It predicts. It pays attention. It models the body. And importantly, it can represent aspects of its own internal activity.

This last ability may have a lot to do with what we mean when we talk about being aware.

I can see my hand moving, but I can also notice that I am angry. I can then notice that I am thinking about why I am angry. The system is not merely constructing a model of the outside world; it is capable, in some sense, of including itself within its model.

To me, there does not need to be another observer somewhere inside the brain watching all this happen. In fact, that would only move the problem one step further. Who would be watching that observer?

Then what is the “I”?

I think the idea of self is related but slightly different.

Consider a country. What exactly is the country?

It isn’t only the land. It isn’t any particular citizen. It isn’t its government, because governments change. People are born and die, borders can change, institutions evolve, and yet we continue talking meaningfully about the same country.

Or consider a car. Replace a tyre and it remains the same car. Replace the battery and it remains the same car. Many of its components can eventually be replaced, yet at the scale at which we interact with it, treating the entire organized system as one thing is useful.

I think the “I” is somewhat like this.

There may not be one indivisible object somewhere inside my brain that is me. There is a body, memories, perceptions, learned behaviour, an internal model, a history and an enormous continuously changing biological system. Together they form something sufficiently coherent and persistent that it makes sense to treat it as one entity and give it a name.

Me.

Again, saying that the self may not be fundamental does not mean that a person isn’t real or important.

This distinction matters to me. Pain does not become irrelevant because pain is ultimately implemented through physical processes. Love doesn’t become meaningless because it depends on a biological brain. A person doesn’t become unimportant because the concept of a person exists at a much higher level than fundamental physics.

Things can be emergent and still matter enormously at the scale at which we live.

What about a conscious machine?

This way of thinking also changes how I think about artificial intelligence.

Imagine that one day we construct an artificial system sophisticated enough to continuously perceive its environment, remember its past, learn from experience, integrate different kinds of information, maintain an internal representation of itself and inspect aspects of its own internal state.

Suppose it tells us that it is thinking. It remembers what happened yesterday. It distinguishes itself from its environment. It reports internal states and reflects upon them.

Would it be conscious?

My inclination is yes.

People might say that it is merely processing electrical signals. But our brains are also physical systems processing signals. Someone could argue that biological chemistry has some special property necessary for consciousness, and perhaps future science will discover that it does. But then I would want to know what that property is and why it matters.

Otherwise we risk defining consciousness circularly as whatever humans possess.

I cannot directly access another human being’s subjective experience either. I infer that other people experience things because of their behaviour, their reports, their biology and their similarity to me. If an artificial system eventually possessed all the relevant functional capacities we associate with consciousness, deciding that its reports are somehow fundamentally different would require a reason beyond simply saying that it is artificial.

Maybe we mistake our categories for reality itself

This brings me back to where I started.

Life, species, consciousness, self and even physical laws are not identical concepts, and I don’t want to pretend they all work in precisely the same way. But I see a common pattern in how we think about them.

Reality develops structures and regularities. At particular scales, some patterns become sufficiently distinctive that treating them as separate things becomes useful. We give those patterns names. The names allow us to think, communicate and build entire fields of knowledge around them.

Sometimes, however, I think we make a subtle jump. Because a concept becomes so useful and familiar to us, we begin wondering where the corresponding thing exists fundamentally.

Where is life?

Where is consciousness?

Where is the self?

Where are the laws that tell the universe what to do?

Perhaps some of these questions arise because we have mistaken the categories through which we understand reality for fundamental divisions within reality itself.

That does not mean the categories are arbitrary. Nor does it mean that everything is an illusion. A cancer diagnosis is meaningful even though cancer is not a fundamental particle. Temperature is meaningful even though thermodynamics describes matter at a different level from microscopic physics. Consciousness can matter profoundly even if it ultimately describes what an extraordinarily sophisticated physical system is doing.

So I am left with a picture of reality that is surprisingly simple at its foundation, even though what emerges from it can become almost unimaginably complicated.

Something exists.

I don’t know why it exists, and perhaps asking why is ultimately a human demand rather than a demand reality has to satisfy. That something behaves in certain ways. Structures form. Some persist. Some reproduce. Complexity accumulates. Life appears. Nervous systems develop. Brains remember and model the world. Eventually some of those brains become capable of modelling themselves and asking what they are.

And then one of those brains looks at the universe from inside this enormous chain of emergence and asks:

Why is there consciousness? Why am I here? What is all this for?

Perhaps there is a deeper answer.

But I am increasingly comfortable with the possibility that, at the very bottom, there isn’t one.