Daniel Dennett's Sweet Dreams: Philosophical Obstacles to a Science of Consciousness is published as part of The Jean Nicod Lectures series. Jean Nicod lectures are an annual event in Paris delivered by philosopher-cognitive scientists. This book contains the lectures that Dennett delivered as part of the Jean Nicod lectures in 2001 along with others delivered as part of the Daewoo Lectures in Seoul, London lecture of 1999, a short essay on Consciousness from Richard Gregory's revised edition of the Oxford Companion to the Mind and a paper reprinted from Cognition 79: 221-237(2001). Sweet Dreams represents Dennett's thoughts on consciousness about a decade after his Consciousness Explained (1991). He says 'It is time for some revision and renewal' (p.ix)

Dennett comments that thinking about consciousness has changed in the last century due to progress in science. He claims that a majority of scientists and philosophers hold dualism to be simply false. What we are made of and from what consciousness emerges are mere physical cells. However at the cellular level there is no sign of consciousness. '…not a single one of the cells that compose you knows who you are, or cares' (p. 2). Hence the mystery that haunts many philosophers and scientists is the emergence of consciousness. Dennett seems optimistic about the strain of work being done in biology and cognitive science as leading to a mechanistic explanation of consciousness. He considers with cynicism the suggestion of some (e.g. David Chalmers) that the solution lies in physics rather than in biology. Dennett points out that the physics of the brain cells is no different from that of the yeast cell. Even if the brain cells are supposed to be different, containing consciousness, then the puzzle would be to explain how the myriad cells produce higher order thoughts such as those of art and so on. This he calls the topic-of-consciousness question. He argues that this question cannot be tackled by 'a "theory" that postulates some fundamental and irreducible sentience-field' (p.11).

There is a fear among some philosophers that any mechanistic understanding of consciousness would fail to differentiate between a conscious human and a perfect zombie. Dennett thinks that to take this zombic hunch as a serious impediment to naturalism one needs a good argument that seems to be lacking. He says that the fear of the zombie is an illusion that we will grow out of. However I think that it is the prerogative of the naturalists to give an argument to nullify the zombic hunch which sadly is absent in Dennett.

In the second chapter he argues that consciousness can very well be studied from a third person perspective or even from a Martian perspective and that such a study would not leave out anything significant. He questions the supposition that Martians intending to study human consciousness would necessarily leave something out. Is there something about Francophone consciousness that non-Francophones cannot grasp or about right-handers that left-handers cannot make sense of? Then there are difficult cases: can a colour blind person understand what colour is? But Dennett thinks that we should not start with such cases. Rather a better strategy would be to understand all our answers to such questions as parts of folk theories of consciousness.

Folk theories are based on intuitions and Philosophy of mind seems to be especially harsh towards theories with counter-intuitive results which lead to a certain kind of unhealthy conservatism. This is more so when the intuitions are native to the philosopher.

Dennett mentions heterophenomenology as a method of studying consciousness where the raw behavioral and internal events in a human subject are recorded and interpreted taking an intentional stance. He says that heterophenomenology prepares a catalogue of what must be explained.  The catalogue also includes a first-person report of the experiences, granting that there might be some experiences which are ineffable. This method, he contends, works for zombies as well as for genuinely conscious beings and hence helps us to put the difficulty of the zombic hunch at bay for the time being. However the situation doesn't seem to me to be that simple. The method presupposes that behavior is generated by an intentional individual. In that sense it presupposes that the behaving agent is not a zombie. This presupposition seems to be philosophically difficult to sustain. But then Dennett questions the zombic hunch itself as a philosopher's illusion.

Then he considers the second-person point of view which takes into account trust and empathy, as distinct from the neutrality or agnosticism of heterophenomenology. Philosophers like Evan Thompson argue that 'sensual empathy' is required for studying consciousness for which one must have similar body types. Martians are not suitable for studying human consciousness. Dennett thinks that we should not start with this assumption.

In chapter three he defies the magical conception of consciousness and says that it is just another physical, biological phenomenon like metabolism or reproduction. Someone trying to explain away the magic of consciousness is taken to be a spoil sport. Dennett talks at length about card tricks and the Indian Rope Trick to understand the element of magic in them, what makes them magical and how it is very much within the limits of natural scientific explanation. He is especially suspicious of Chalmer's Hard Problem. Though he admits that it cannot be proved that there is no Hard Problem, one can hardly prove that there is one.

In chapter four Dennett tackles the qualia issue. He says that it is difficult to deny that there are qualia but that is because the concept itself is elusive. He brings in the case of change blindness in order to show that we are often confused or in the dark about our own experiences. If the qualia are not even available for first-person verification then a science of such a state becomes impossible. Thus he argues that heterophenomenology is the best available method for studying consciousness. The concept of qualia, he remarks, is in a mess and philosophers are not clear about what they mean by it. However his argument against the position that a change in qualia takes place only when the change is noticed seems unclear.

In chapter five Dennett discusses Frank Jackson's 'Mary in a B&W world' thought experiment. He proposes an alternative to the hypothetical Mary being surprised on encountering colors situation by suggesting that it is similarly possible that she is not surprised as she has all the physical information about the colors as per the thought experiment. Dennett as an exponent of thin materialism contends that Mary doesn't learn anything new on encountering color. He says 'that Mary had figured out, using her vast knowledge of color science, exactly what it would be like for her to see something red, something yellow, something blue in advance of having those experiences' (p.106). According to him the idea that you cannot deduce what a color looks like if you have never seen one is an interesting folk theorem without any scientific backing.

In chapter six, Dennett takes on the issue of explaining consciousness, something termed as a 'hard problem' by Chalmers. Dennett however thinks that the notion of 'hard problem' is a theorist's illusion. He compares consciousness to fame characterizing it as a phenomenon that needs some actualization of the potential (p. 141). This 'fame in the brain' theory contends that different happenings in the brain form a clout and gain attention just like any celebrity does. Now the question is how does this take place? Hence one cannot duck the so-called 'hard problem' but needs to tackle it and that, Dennett believes, can be done following heterophenomenology. 

In the seventh chapter Dennett talks about his fancily named 'fantasy echo theory of Consciousness'. Here he argues that the most important characteristic of consciousness is its ability of self reflection, to produce an echo of an experience. In the eighth chapter he mentions this ability as that of being able to 'notice that we notice things' (p.174). He compares the notion of qualia with that of vitalism and thinks that understanding consciousness in terms of qualia is a mistaken move.

As a collection of pieces written over a period on issues relating to consciousness Dennett's Sweet Dreams is refreshing and challenging without being philosophically heavy. In this sense it should be accessible to a wider audience interested in reading about philosophical issues in understanding consciousness.

© 2007 Anirban Mukherjee

Anirban Mukherjee is a PhD student at the Department of Philosophy, University of Reading, UK and Lecturer in Philosophy, University of North Bengal, India

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Categories: Philosophical, Psychology