Inner Presence by Nigel Leary

Consciousness as a Biological Phenomenon
by Antti Revonsuo
MIT Press, 2005
Review by Nigel Leary
Nov 7th 2006 (Volume 10, Issue 45)

While I found Revonsuo’s style engaging and the subject matter fascinating — although I must admit to having a vested interest in this type of consciousness research — I found myself somewhat disappointed with the philosophical meat of Inner Presence. Revonsuo’s main thesis concerns the development of a new metaphorical framework for consciousness, the ‘world-simulation metaphor’ (p. 119), which, allegedly, provides us with a new internalist conception of experience. However, I am getting ahead of myself.

Revonsuo’s project, or at least his intended project, is to provide an account of consciousness as a biological phenomenon within the brain, and to go some way to unifying what has become a melting pot of philosophical, psychological, neuroscientific and cognitive scientific research — much of which, like ships passing in the night, fails to receive significant, if any, recognition from the other respective disciplines. Revonsuo’s view is that cognitive neuroscience is the vehicle for the empirical study of consciousness, and that ‘it should be a biological research problem after all’ (p. 9, original emphasis). This may or may not be true, but what is admirable about Revonsuo’s book is that he is trying to take some account of all these positions.

Chapter two, for example, has a good section entitled ‘Basic Concepts of Consciousness’ which offers a clear introductory explanation of some key concepts deployed in the consciousness debate. That being said, even at this early stage Revonsuo gives particular weight and overall significance to the concepts he intends to employ in a fashion which is more assumption that vigorous justification. In this case I am referring to ‘Presence’ and Revonsuo’s statement that it is ‘perhaps the most fundamental feature of all the elements in phenomenal consciousness’ (p 33). While I agree with the author that phenomenal experience does need to be occurent, which is what he means by present: actually occurring, for it to have an impact on my subjective, personal experience, that is not the same as the somewhat larger claim Revonsuo makes that presence is the most fundamental feature of conscious experience (a claim that I believe needs far more justification than it receives). On the positive side chapter two does make some headway in mapping the conceptual territory, as its title suggests, which would provide a decent starting point for anyone interested in consciousness studies, but I remain unconvinced that this apparent benefit outweighs the remainder of the books quality.

The overly brief and hasty dismissal of some alternative approaches to consciousness, in chapter eight, is profoundly disappointing to say the least; to see robust philosophical approaches dismissed within two to three pages never inspires confidence and, as anyone who is even slightly familiar with the literature will tell you, fails to do justices to the rich and vibrant theoretical approaches available. There are also certain consequences to such brief rebuttals: the first being that a two page account is often insufficient to even represent a given theory accurately, let alone argue effectively against it. As a result, Revonsuo’s account of the alternative theories trades accuracy for brevity, resulting in the incorrect representation of certain approaches to the problem of consciousness (in particular the section on HOT theories of consciousness is inaccurate and conflates at least two variations of this position). This, to the discerning eye, leaches the book of authority: why should the reader have confidence in a thesis which misrepresents its opponents? While this section is certainly laudable for its scope the lack of accuracy dictates that its application is at best introductory, which is unfortunate as the motivation behind such an endeavour is well founded but, it would seem, overly ambitious.

Revonsuo’s positive thesis employs dreams (and dreaming) as a model system for the exploration of phenomenal consciousness, purporting to justify the employment of dreaming as a model system (although perhaps not successfully) through the observation that phenomenal consciousness is all there is in dreams. The central claim is that the dreaming brain reveals phenomenal consciousness in a ‘very special, pure, and isolated form’ (p. 75). Furthermore Revonsuo goes on to argue for the following three theses:

1. The dreaming brain generates (or supports) phenomenal consciousness.
2. Phenomenal consciousness generated by the dreaming brain includes the full range of phenomenal contents.
3. Phenomenal consciousness generated by the dreaming brain has similar overall form as phenomenal consciousness during wakefulness.

Although I do not have the space in a review to argue constructively against any of these theses (and not wanting to fall foul of my own criticism that rebutting robust theories in a few pages is poor practice — if indeed Revonsuo’s theory can be construed as such) it seems to me that there are obvious problems with 2 and possibly 3. Take two, for example: it can only be true if, prior to dreaming, the brain has had access to the full range of phenomenal contents i.e. something already experienced. I am appealing to the common sense assumption that it is impossible to dream about totally unexperienced phenomenal contents. If I was unfortunate enough to experience, say, monochrome vision (I see only in shades of black, white and grey) then it should be fairly obvious, and uncontentious, to say that I could not dream in color (See Frank Jackson’s seminal work on ‘What Mary didn’t Know’, and the huge amount of accompanying literature) as I do not have access to that particular branch of phenomenal content. Thesis two, then, should be perhaps be more conservative and include the caveat that the phenomenal concepts available to the dreaming brain are only those delivered by experiences thus far enjoyed by the wakeful brain: the phenomenal content needs to originate somewhere. If we accept this it seems to me that the dreaming brain may indeed be an isolated form of phenomenal experience, but that it is wholly reliant on the wakeful brain for the phenomenal contents it employs, and thus not necessarily a good candidate as a model system. After all what use is a model system of phenomenal consciousness that inherently has no, or almost no, phenomenal content itself?    

Although I admit that the model of the dreaming brain does isolate phenomenal consciousness viewed in a certain light I am highly skeptical, and remain totally unconvinced in light of Revonsuo’s arguments, that its application as a model is in any way useful. Our only access to the dreaming brains of other people, in terms of phenomenal consciousness, is via their reports, and, as Revonsuo admits — although he argues in favour of the veracity of testimony as empirical data — these reports are likely to be assailed by a range of extrinsic influences to do with memory, interpretation and so on.

Whilst much contemporary opinion subscribes to the view that the brain and consciousness are inexorably tied together, although there are many diverse theories suggesting how this might be explained, and that consciousness is, somehow, reducible to the brain, Revonsuo’s metaphorical contribution to the debate seems to be wholly odd. His intention is to build on his dream model to construct a world-simulation metaphor that ‘captures the essential features of the phenomenon [consciousness] in a single, captivating picture’ (p. 99), his picture being something akin to virtual reality. Is he successful? Personally I think not. Although Revonsuo’s book does highlight some good points — for example that, thus far, empirical research has not achieved the reconstruction of phenomenal consciousness via the various scans and investigative resources, aimed at that brain, it has at its disposal — it seems to me too fanciful and problematic to gain real purchase within the contemporary philosophical debate. I have, the reader will notice, restricted myself to the ‘philosophical’ debate as I am a philosopher (or philosopher in training) and not a cognitive neuroscientist nor a psychologist, but I think that any theory that builds its explanatory force on the foundation of dream models is going to experience problems in gaining general acceptance, especially if you consider that the information we have about them is totally reliant on the testimony of the dreamer.

On the whole although the style and tone were engaging I found the brevity of what I took to be key discussions disappointing. The metaphor while innovative remains inadequate, and lacks, in my opinion, decent philosophical purchase. There are some positive elements to Revonsuo’s book, but these are, for me, overshadowed by the oddity of the positive thesis, and the lack of accuracy and depth on the dismissal of the alternatives. This book is an ambitious project to be sure, but one which I find unconvincing and, at times, incomplete.

© 2006 Nigel Leary

Nigel Leary is currently studying for a PhD at the University of Birmingham, working on the AHRC funded Metaphysics of Science Project. Broadly speaking his area of research is Natural Kinds as they appears both in post-Kripkean philosophy of language and in recent work in the philosophy of science and the metaphysics of laws. More specifically his research is focused on a metaphysics of mind question of whether Natural Kinds can be applied in any useful fashion to the problem of mental causation, and his intention is to argue that the mental can be causally efficacious.