Consciousness

This page brings together my views on consciousness: why it matters, how our common-sense picture of it is mistaken, and why the mystery of how it arises remains so important.

I approach consciousness from three angles: its central importance, the ways in which science and philosophy have overturned common sense, and the still-open question of how consciousness arises.

Consciousness as Pivotal

Consciousness is pivotal to our place in the universe. We each inhabit two worlds: the subjective world of our conscious experience and the objective world that exists beyond it.

Our thinking should respect both perspectives, rather than trying to reduce one to the other. The subjective world is where life is lived from within; the objective world is the wider reality in which that life takes place. Our anxiety about mortality partly reflects the contrast between the brief duration of our own subjective world and the continuing existence of the objective world.

Consciousness arises within the physical universe, but it seems to be only through consciousness that anything is experienced, and in conscious life that value has its clearest home. Space and rocks do not matter in themselves; what matters is the quality, valence, and shape of conscious life. Our practical reasoning and morality are therefore largely directed towards improving subjective experience.

If the aim of life is, in broad terms, good conscious experience, then a better understanding of consciousness and its hedonic tone is critical. We need to understand not only how experience arises, but also how it becomes positive or negative. This matters both for our own lives and for morality more generally, because improving the world largely means improving the quality of conscious experience within it.

Each conscious creature has its own subjective world. The objective world therefore contains a vast number of parallel subjective worlds, each shaped by a creature’s body, senses, needs, capacities, and environment. Human beings are only one case within this wider field of conscious life.

Yet we know little about what experience is like for non-human creatures. This ignorance matters because it limits our understanding of how much good and bad conscious experience exists in the world, where it exists, and what would improve it. We may often not know what is best for animals, or how much weight to give their interests. Reducing our ignorance about animal consciousness is therefore important not only scientifically, but also morally, because it bears directly on how we should treat other conscious beings.

New Scientific Understanding

Science and philosophy are already showing that consciousness is very different from what common sense assumes. We have evolved to think about consciousness in certain ways, but a different picture is emerging. I see five critical points:

First, dominance: common sense treats consciousness as the dominant part of the brain. This is not true. Almost all of what the brain does is non-conscious, including motor control, intuitive reactions, language, face recognition and learned behaviours. Consciousness is better understood as a limited subsystem within the wider brain: not the whole operating system, but more like a special-purpose smartphone app that presents selected information in a useful form. We naturally think consciousness is foremost because it is what we experience, but the rest of the brain is doing vast amounts of impressive work beneath the surface.

Second, perception: we may think that in consciousness we directly perceive the world, but the brain is better understood as constructing a model of the world. This world-model is a real-time simulation that gives us a strong sense of presence. It is selective and sometimes distorting, representing in user-friendly ways the aspects of reality that have mattered for survival and action. The model is also ‘transparent’: it is designed not to appear as a model, but simply as the world itself.

Third, self: we have strong intuitions that consciousness includes an unchanging ‘self’ that has our thoughts and perceptions. But neither introspection nor neuroscience reveals such a fixed experiencer. As Hume put it, we are closer to a ‘bundle of perceptions’ than to a simple inner subject. A person is unified by psychological continuity, not by an unchanging essence.

Fourth, will: we think of ourselves as exercising free will from outside nature, as if the conscious self stands apart from the physical world and directs the brain. A better view is that the brain controls action through natural processes, while consciousness models aspects of that control from within. The experience of willing is real, but not evidence of a separate power outside nature.

Fifth, self-knowledge: we assume that we know our conscious minds directly and infallibly, but we are mistaken. We think we see the whole visual field in detail, although most of it is only sketched in. We move in and out of conscious attention without noticing the transitions. And other people may sometimes read our expressions more accurately than we can introspect our own feelings. Our access to consciousness is therefore real but fallible.

These five points are important, but still not widely enough appreciated. Part of the task is therefore to make this newer understanding part of our ordinary picture of ourselves.

The Mystery of How Consciousness Arises

Even after these common-sense mistakes have been corrected, the deepest question remains: ‘How does the brain produce conscious experience?’ This is the so-called hard problem of consciousness and may be the greatest unanswered question in science and philosophy. Subjective experience seems unlike anything else in the physical world. It is therefore understandable that some conclude that we will never reach a purely materialist explanation.

But there are reasons to think progress is possible. We are learning that consciousness is less powerful, less unified, and a smaller part of brain activity than common sense assumes. At the same time, neuroscience is increasingly mapping conscious experience onto processes in the brain. It may be that, over time, our idea of what consciousness is will come into line with our understanding of how it is produced. The mystery may then be reduced, or partly dissolved, much as the mystery of life was dissolved by biology.

This would still leave consciousness as pivotal. It is the most significant trick of nature: a process through which the physical world acquires a further dimension. Consciousness is an organism talking to itself, modelling its world, its body, its actions, and its place among other conscious beings. Understanding consciousness therefore matters not only for science and philosophy, but for understanding value, ethics, and ourselves.