Download Conscious Experience

Conscious Experience
edited by
Thomas Metzinger
Imprint Academic
Schöningh
1995
Cover photograph: Sense of Sight/Superimposed brain image by Bassem Mora and George
Carman, ©Joseph McNally Photography/National Geographic
British Library Cataloguing in Publication Data:
A catalogue record for this book is available from the British Library.
© 1995 Ferdinand Schöningh, Paderborn
English language edition published in association with Imprint Academic
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Printed in the USA by Allen Press, Lawrence, Kansas
ISBN 0 907845 05 3 (paperback)
ISBN 0 907845 10 X (hardback)
Editor's Introduction
Thomas Metzinger
T[lze Problem of Consciousness
I. Do we need a new science of consciousness?
How can consciousness arise in a physical universe? Is it at all imaginable
that something like conscious experience could emerge from a purely
physical basis? Is it conceivable that subjective sensations and the emergence of an inner perspective are part of the natural order - or are we now
confronted with an ultimate mystery, a grey area an the scientific map of
the world that may in principle have to remain grey?
Today, the problem of consciousness - perhaps together with the question
of the origin of the universe - inarks the very limit of human striving for
understanding. It appears to many to be the last great puzzle and the greatest
theoretical challenge of our time. A solution of this puzzle through empirical research would bring about a scientific revolution of the first order.
However, in this case meeting the challenge may require a completely new
type of intellectual revolution, for a number of reasons. To begin with, when
we look closely, it is not at all clear what the puzzle of consciousness
actually is, and what we would accept as a convincing solution. Second, the
problem in a strong sense concerns ourselves: it is always our own consciousness, among others, that we want to understand. Therefore the problem of consciousness is also a problem of self-knowledge. It affects all of
us, not just philosophers or scientists. Third, such a revolution - if it
actually took place - might for this reason have greater social and cultural
ramifications than any previous theoretical upheaval. This could be due to
the consequences of a radically changed picture of ourselves, or to the
impact of new technologies that might result, for instance, from progress in
the neurosciences or in artificial intelligence research. These three reasons
have recently led to an increasing restlessness in the sciences as well as to
a growing interest among the general public in questions concerning the
connection between consciousness and the brain.
It has become obvious that, for quite some time, we have been reaching
for a new theory of mind. Such a new theory will, among other things, be a
THOMAS METZINGER
theory about the nature of conscious experience. It also has the potential to
be the first such theory in the history of mankind to rest on a solid empirical
basis. There seems to be a theoretical revolution in the air, which can be
expected to affect the way in which we see ourselves in a hitherto unknown
fashion. Although empirical research has given only a few indications of
this so far, the puzzle of consciousness has already advanced to become the
`secret research frontier' in a number of scientific disciplines. This development in turn has met with great interest among philosophers.
For the last ten or fifteen years philosophers have shown a rapidly
increasing interest in the problem of consciousness. A number of new
journals and academic organisations have been founded, and large meetings
on the subject are taking place with increasing frequency. Interest has been
further stimulated by the emergence of serious claims about consciousness
in disciplines ranging from quantum physics through neurobiology to cognitive science. In the philosophy of mind many ofthese proposals have been
watched closely. At the same time, more and more empirical researchers are
beginning to realize that philosophers have been dealing with this theoretical problem for many centuries, and that philosophical analysis has a central
role to play in its resolution. In its origins the concept of consciousness is a
philosophical concept. As a consequence, there is now increasing interest in
a serious and empirically-informed philosophy of mied in the general public
and in the neuro- and cognitive sciences. This is also revealed by the simple
fact that a number of prominent scientists researching the brain have
published popular books with philosophical content.'
This rising interest is also shown in the increasingly firm connections
between philosophy and the adjoining areas of research in neuroscience,
cognitive science and computer science. Many hold that the necessary
revolution can only occur when our understanding of the subject transcends
disciplinary boundaries and links between the relevant areas of research are
drastically increased. However, it has also become obvious that a systematic integration of research activities is necessary as well. This situation has
led to a call for a new science, the science of consciousness, 2 both from
empirical and theoretical researchers. In considering this fascinating idea,
one must bear in mind two caveats. First, the idea of a `science of consciousness' is anything but a new idea, especially from the viewpont of the
philosopher. For example, the whole phenomenological movement (and its
demise) can be understood in these terms. In a more general sense, philosophy
— as the love of wisdom and queen of the sciences — has always been the
science of consciousness. The ideal of self-knowledge is a classic ideal of
1
A selection of these can be found in section 1.3 of the bibliography in Appendix I of this book.
Cf. Penrose 1994: 7 ff. Further important contributions to the debate concerning an independent
science of consciousness are Baars 1988, Chalmers 1996, Flanagan 1992: 213 ff., Revonsuo
1994: 249 ff., the collection of texts by Hameroff et al. 1996 and the ongoing discussion
subsequent to Chalmers 1995. Sec also Greenfield 1995, Scott 1995 and Velmans in press.
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THE PROBLEM OF CONSCIOUSNESS
philosophy. So professional philosophers may well regard the current
euphoria over consciousness with a degree of scepticism, seeing it as
merely the Tatest intellectual fashion. Secondly, the success of such an
undertaking is by no means assured. One has to ask: does the concept
`consciousness' really define an independent and coherent domain, a subject area that could correspond to an autonomous area of research ? 3
What would be the subject, methodology and aim of such a research area?
This brings us back to our starting point: what is the real problem of
consciousness? Can it be approached by means of the natural sciences at
all? What exactly do we wart to know? These questions — especially the
last one, the setting of the epistemic goal — are typical philosophical
questions. As philosophers we also want to know how it is possible that a
phenomenon as complex as consciousness could arise in a physical Universe: we are looking for a conceptually convincing analysis of the phenomenon and its relationship to the objective world. The first aim,
therefore, is conceptual clarity and freedom from contradiction. As empirical researchers, on the other hand, we warst to know how all this actually
happened: we are interested in the history of the phenomenon in our own
world. Is there a neural correlate of consciousness? Which forms of information processing in the brain lead to those states which we call conscious
experiences? Such questions are central to the second goal on our way to a
better understanding of the phenomenon of conscious experience. This goal
is the achievement of an empirically meaningful and informative theory of
consciousness.
How can the emergence of conscious experience be reconciled with the
laws of nature that dominate this world? As far as we know, consciousness
is a very recent phenomenon in the physical history of the Universe. Once
again we can say, in a certain sense, that we ourselves are the phenomenon
in question. The emergence of organisms with highly organized nervous
systems, and soon afterwards of human beings, are events that from a
cosmological viewpoint have only just occurred. The idea that, in a strong
sense, we ourselves are the phenomenon in question, leads to a third
provisional answer to the question what we actually expect from a satisfactory theory of consciousness. To be convincing, such a theory raust not only
be conceptually coherent and empirically plausible: we must also be able to
accept this theory as a theory about our own inner experiences. It raust
account for the subtlety and phenomenological wealth of this experience
and take seriously the inner perspective of the experiencing subject. Above
all, it must explain the connection between one's own first-person perspective and the third-person perspective of science operating from the outside.
If it turns out that our intuitions about consciousness and the interpretation
of these intuitions by folk psychology prove radically wrong, then such a
Concerning sceptical considerations of this point, cf the papers by Kathy Wilkes, Martin
Kurthen and David 1'apineau in Part 2 of this book.
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THOMAS METZINGER
theory raust offer a detailed explanation of why we are so wrong about the
matter. Fortunately, there is a wide consensus that a serious theory of
consciousness must account for the phenomenological wealth, colourfulness and variety of our inner life. In the philosophy of mind at least, there
are only a few examples of naive and ideological forms of reductionism: it
has long been clear that a primitive scientism, attempting to bulldoze the
subtlety and depth of our conscious experience simply by introducing new
materialistic jargon, would be evading the real problems.
The problems on the path to a convincing theory of consciousness differ
fundamentally from other unsolved problems in the natural sciences.
Although physics, chemistry and biology have solved many of the fundamental puzzles in their respective domains, a considerable number of grey
areas on the map have remained. These sciences are far from being able to
describe exhaustively the parts of reality which form their own subjects of
research. However, where there are liragering mysteries in physics, chemistry and biology, it is at least clear what would be accepted as a solution of
the problems. This is not so for the problem of consciousness, for a number
of reasons.
To be able to speak seriously about a science of consciousness, a number
of fundamental questions would have to be answered. It is interesting to
note that with the emergence of consciousness, private worlds — spaces of
inner experience — are opened up. These spaces, however, are individual
spaces: ego-centres of experience that suddenly appear in a centreless
universe. 4 Each such centre of consciousness constitutes its own perspective on the world. This perspective is what philosophers sometimes like to
call the 'first-person perspective'. A phenomenal world of its own is tied to
each of these perspectives. These individual worlds of experience also
possess a historical dimension: almost always a psychological biography
emerges together with them — what we call our `inner life'. This too can
be seen as the history of the genesis of a world, or aphenomenal cosmology:
within each of us a cosmos of consciousness unfolds temporarily, a subjective universe develops. The first part of the problem is to understand how
such a variety of subjective universes can constantly form and disappear in
our objective universe. Empirical research on the evolution and neurobiological genesis of consciousness is relevant here, but there is also a philosophical aspect to the problem. This consists in understanding how we our
selves can be such subjective universes, and above all in understanding the
meaning of it all. Do we really understand what we are saying when we describe ourselves as dynamic subjective universes, that have something like a
centre and temporarily light up in an objective universe? I do not think we do.
Before our general ideas and epistemic goals can be turned into concrete
research projects, we need a careful conceptual analysis of the problem.
In the more recent discussion no one has highlighted this point as clearly as Thomas Nagel.
Cf. Nagel 1974, 1979, 1980, 1986.
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