Some philosophers, notably Colin McGinn, have simply given up and declared that this is a question that cannot be answered by the human mind. For Seth this attitude is too defeatist. He is not certain that a fully satisfying answer can be found; perhaps we will have to accept that consciousness is simply a brute fact about the universe, or we may find an answer but not one that gives us a sense of completion. In the meantime, however, it may be better to avoid a frontal assault on the problem.
In this book he doesn't attack the hard problem directly but instead deals with what he calls the 'real problem'; if we can solve this, he believes, the hard problem may not be so much solved as dissolved, rather as the once widely accepted doctrine of vitalism, which held that there is a mystical life force animating all living systems, faded away as increasing knowledge of biology and biochemistry showed that it was an unnecessary hypothesis.
According to the real problem the primary goals of consciousness science are to explain, predict and control the phenomenological properties of conscious experience. This means explaining why a particular conscious experience is the way it is—why it has the phenomenological properties that it has—in terms of physical mechanisms and processes in the brain and body [author's emphases].So how does this work?
A key idea that appears again and again throughout the book is that consciousness is a form of controlled hallucination. Contrary to what we intuitively believe, when we open our eyes in the morning we don't see the world directly. It isn't a given; we construct it in a series of guesses about what is out there. There will be errors in this, and they are corrected by information arising via our senses. Hence what seems like a direct perception is actually a construction, which Seth refers to as a hallucination. As the philosopher Immanuel Kant believed, objects do exist but their true nature is hidden from us.
Normally we are unaware of this process but it can be revealed by visual illusions. A particularly striking example discussed by Seth is the picture published a few years ago on the internet showing a dress which half the population swear is blue and black in colour while the other half are equally certain it is gold and white. Experiments like this reveal what is really happening when we think we simply perceive an object.
Another even more profound intuition we have to give up is that there is a self behind our eyes which is somehow observing the world. In fact the self, like the outer world, is a hallucination, but instead of arising from the outer world it is based on our own bodies and the sensory information that emerges from the physiological changes occurring within us.
This way of thinking about the self is important because it shifts the focus from the brain alone to the brain plus the body. And that in turn leads to he idea of the 'beast machine'. This phrase was originally coined by Descartes to refer to his belief that animals lack rational souls and are therefore automata. Seth reverses this, to say that humans are also beast machines and that this is just what makes them conscious. We are machines that have been shaped by evolution to be aware of our own bodies and hence self-conscious.
Our conscious experiences of the world around us, our selves within it, happen with and through and because of our living bodies. Our animal constitution is not merely compatible with our conscious perception of self and world. My proposal is that we cannot understand the nature and origin of these conscious experiences except in the light of our nature as living creatures [author's emphasis].On this hypothesis humans are not unique in being conscious. How far back it goes in evolution is hard to know, but Seth has little doubt that at least all mammals possess some form of consciousness. And he has a quite extensive discussion of the octopus, which offers the nearest thing to an alien intelligence that we can meet on this planet.
What about non-living systems? Seth is unsure whether a machine could ever be conscious, though he doesn't rule it out. However, he makes an important point which I haven't seen discussed by anyone else. He distinguishes consciousness from intelligence. The assumption that they are the same underlies the widespread belief that as computers become ever more capable they will inevitably acquire consciousness. But this isn't true. We are intelligent organisms and our intelligence has enabled us to transform the world, which leads us to over-value intelligence. But consciousness and intelligence are not synonymous. For a machine to be conscious it would need to be specifically designed for that purpose.
Philosophically Seth favours physicalism (materialism), as he declares early on. "This is the idea that the universe is made of physical stuff, and that conscious states are either identical to, or somehow emerge from, particular arrangements of this physical stuff." He says that this is the default position of many neuroscientists. But it doesn't prevent him from ranging pretty widely in the conclusions he draws from his work.
What excites me most about this way of thinking is how far it may take us. Experiences of free will are a perception. The flow of time is a perception. Perhaps the three-dimensional structure of our experienced world and the sense that the contents of perceptual experience are objectively real—these may be aspects of perception too. The tools of consciousness science are allowing us to get ever closer to Kant's noumenon, the ultimate unknowable reality which we, too, are part of. All these ideas are testable, and whichever way the data come out, simply posing questions of this kind reshapes our understanding of what consciousness is, how it happens and what it is for. Every step chips away at the beguiling but unhelpful intuition that consciousness is one thing—one big scary mystery in search of one big scary solution.Ultimately, of course, consciousness research is about us.
All this being said, facing up to the mystery of awareness is, and always will be, a deeply personal journey. What good is a science of consciousness unless it sheds light on our individual mental lives, and on the inner lives of those around us?At the beginning of the book Seth writes about his experience of surgical anaesthesia as a temporary cessation of being. In the end, of course, we will all undergo this permanently, "when the controlled hallucination of being you finally breaks down into nothingness.... a return to the eternity that each of us at one time emerged from." We really don't know what, if anything, happens then. "At the end of this story, when life in the first person reaches its conclusion, perhaps it's not so bad if a little mystery remains."
This book is neuroscience as it should be written, with just the right blend of (mainly) science plus a seasoning of philosophy and the personal.