Evolving the Mind: On the Nature of Matter and the Origin of Consciousness [Paperback]

Cairns-Smith is a reader in Chemistry at the University of Glasgow and so understandably his approach to the topic of consciousness is a very chemical one. The book starts with a discussion of chemistry and physics, moves on to DNA and cellular mechanics, then primitive organisms, before discussing neural behaviour and consciousness itself. Everything is presented in a clear, fluent way with plenty of diagrams, so this book is easy to read and understand - but at the same time doesn't skimp on detail.

The author presents us with the idea that an increasing complexity of behaviour, the pinnacle of which is human consciousness, is a result of an increase in the complexity of the underlying chemical machinery. But when it comes to our brain Cairns-Smith claims that there is more going on here than merely massive interaction between a huge number of specialised neural cells. He claims that neurons are so precisely specialised that they are capable of tapping into some of the most basic physical properties of matter - namely quantum effects - bringing the book back to its opening chapters' discussion of the physical nature of matter. While this is an elegant argument, ultimately I believe it does not convince - it seems overly fashionable and lacking evidence. The history of the philosophy of mind is littered with metaphors for consciousness based on the topical technology of the day. The brain has been seen as a hydraulic device, a telephone exchange, a digital computer and now Cairns-Smith proposes the metaphor of the very latest quantum physical phenomenon - a Bose-Einstein condensate. This weak conclusion does not detract from the rest of the interesting discussion in the book and anyone with an interest in cognitive science or the philosophy of mind would enjoy it.

"Evolving the Mind" is an excellent book about the material basis of consciousness from an unorthodox but thoroughly clear-headed and scientific point of view. The style is conversational, accessible, and entertaining. The discussion focuses on the essential concepts and questions, avoiding various philosophical "isms" (e.g. functionalism, dualism, etc.) that tend to inflame intellectual prejudices and cloud the real issues.

There are many recent books about scientific theories of consciousness (some very good), but frankly many of them are saying nearly the same thing: consciousness is to be identified or associated with some particular aspects of computation (e.g. planning, decision-making, self-representation, etc.) among neurons in the brain. In these theories, while random noise is understood to affect processes at the sub-cellular level, the brain at the functional level is assumed to operate as a deterministic computing machine. This assumption is present even in current sophisticated theories involving chaotic dynamics, parallel distributed processing, or feedback (a.k.a. "re-entrant connections").

Because Cairns-Smith's writing style is conversational, open-minded, and non-confrontational, some experts (e.g. neuroscientists, cognitive psychologists, computer scientists) are liable to miss the powerful challenge to mainstream approaches to a fundamental theory of consciousness running through his book. This main point has two parts. First, based on the correspondence between conscious experiences and evolutionary fitness (e.g. fire feels bad, food tastes good), consciousness must have evolved. If it evolved, that means (according to evolutionary theory) it must have some effect on the organism's physical body or behavior. Second, since in contemporary neuroscience models the dynamics of the brain are completely determined by the local "mechanical" action (by electro-chemical signals) of neurons, conscious feelings cannot have any effect on the brain's behavior. Various ways have been tried to wiggle out of this, but it's a real problem--conscious feelings aren't allowed to have any effects on the organism's structure or behavior, but that's inconsistent with their evolution by natural selection. As Cairns-Smith details, this problem was clearly spelled out by William James before the solution favored by Cairns-Smith, using 20th century physics, was even conceivable.

To arrive at his outline of a solution to his impasse, Cairns-Smith starts from a lovely historical introduction to relevant ideas from physics, chemistry and neurobiology. Another reviewer dismissed this approach as a mere bias due to Cairns-Smith's background in chemistry. That's an unfair conclusion, because Cairns-Smith builds a strong case that the physical composition of the brain, and not just its functional organization, is important for understanding consciousness. Ultimately Cairns-Smith proposes that large-scale quantum states may provide a substrate for consciousness in the brain together with a resolution to the problems faced by classical models. Again, another reviewer dismisses this as merely the latest in a line of "fad...metaphors" for the mind in terms of the latest technological device. I disagree; I don't think that reviewer fully engaged the arguments put forward in the book.

I somewhat agree with the reviewer who complained that the book lacked a conclusive final chapter. The last chapter is a dialogue between a proponent and a critic (said to be based on a conversation with Francis Crick) rather than a summary and conclusion. This is in line with the atmosphere of the book as a free inquiry into the possibilities, as opposed to a dogmatic adherence to a pre-determined conclusion. Also, the book ends just at the point where one would hope to find a detailed neurobiological model. That's probably as it should be, though, given the variety of possibilities and the lack of specific evidence. But again experts are liable to think that this openness and vagueness justifies their belief that the quantum mind hypothesis is implausible or already ruled out. (A technical example: many scientists consider that macroscopic quantum effects cannot occur at room temperature in the brain, a viewpoint buttressed with calculations by Tegmark. These calculations apply under equilibrium conditions, but not under conditions when energy is pumped into a system, such as the ATP energy continually pumped through biological cells. A rigorous model by Frohlich shows how the kind of quantum states proposed by Cairns-Smith can arise in biological tissue at room temperature. Cairns-Smith covers the Frohlich model, but does not bog down his discussion by emphasizing that the Frohlich model effectively answers the brain temperature objection.)

The reputation of quantum theories of consciousness often suffers from an association with new age philosophies or anti-scientific mystical attitudes. Among the more reputable proponents of a quantum mind model is Roger Penrose. However, the complexity and subtlety of his argument can leave his conclusions in doubt even for readers with an open mind and some relevant math, physics, or logic background. Like Penrose, Cairns-Smith never wavers from scientific rigor. This is especially remarkable since a major thrust of his book is to make a historical case for boldly imaginative thinking, highlighting the controversial additions of "spooky" concepts to the scientific world-view. Ultimately, testing the quantum mind hypothesis will require models that specify the interaction between putative quantum states and the well-established neural machinery of action potentials and synaptic transmission. "Evolving the Mind" provides an excellent background for evaluating such specific neurobiological models.

I highly recommend this book, whether to introduce the issues to a novice, or to loosen up an expert who thinks he already has it all figured out.

There was a joke about a student who summarized the knowledge of a course into a series of sentences such as "Read only your good books in vacation" (Colors of the light spectrum in order: Red, orange, yellow, green, blue, indigo, and violet.) He then summarized these into words and continued this until one final word. It seems he got to final exams and forgot the word! Arrgh!

Well, I just finished reading this book and it managed to summarize and integrate all physics, evolution, chemistry and brain physiology into 300 pages without leaving out any detail however arcane. I will now reduce this to even less, so you will have something more convenient to forget.

The first 95% is background material starting with forces, fields, uncertainty, mass, etc. and leading up to electrons, atoms, water molecules, lipids, and arriving at life which, in the case of the E. coli, already has modest nerve-like capabilities so it can approach food and flee poisons. It goes on to show how nerve cells not much advanced from E. coli are constructed and act to assemble three dimensional images from eye signals, etc. This is to the painful detail of enumerating the parts of the brain and how they interact.

Now we are all familiar with nonsense philosophy where someone who has been exposed to little knowledge nevertheless comes to some fantastic conclusion such as "maybe the entire Universe is an electron in some larger scale Universe". Such speculation, although possibly true, is not interesting because it is not based on any evidence, however flawed and slight.

This book also proceeds to such a fantastic conclusion, but with evidence that is neither obviously flawed nor slight. The problem that it finally addresses is that there is no place in the brain which is connected to all others and which becomes significantly active during consciousness. Such a place would have a huge amount of computing to do to account for our feeling of awareness and would therefore be easily located.

The fantastic conclusion is that there is another kind of activity going on involving probably the white matter in the brain and the cell walls. This activity is at the sub-atomic level and, because of the fact that such activities (as shown by the first 95%) can act over large distances instantaneously, it has the potential of integrating all brain cells. The subconscious brain, i.e. the primitive part constructed of neurons using chemistry and electricity, does the work. It integrates the signals from our sensors and coordinates our movements. It wants food and revenge and fears predators. It spells words and remembers faces. But it has evolved in this environment of atomic forces and uses these for integration, just as the flower uses the bee for pollination. We perceive this as consciousness. This is required so we can plan, chose undesirable short-term actions for long-term gain, avoid the truck while riding the bike, etc.

The book then seems to end without a last chapter. I supply a possible summary of one here.

You can turn the gas off, and the flame will die. But when you turn it on again, the flame comes back to life. When the real brain feels the need for consciousness to resolve some fear, it can turn it on while suppressing input/output and benefit from having the dream engage in scenario evaluations. When it feels the need for more tangible results, all systems are go and we wake up. But to the consciousness this is not much different from the dream. Finally, all this takes energy and it becomes necessary to shut down to refuel and repair. You can't dream all the time.

Where does the consciousness go when it is off? The same place the flame goes. Out.

Where does the flame go when the stove is gone? Permanently out. (And it doesn't care.)