I fully agree with Louis Brassard’s statement ''It is not possible to prove consciousness because it is a subjective perception.”   This subjective perception acquired in the traditional way is called “subjective science” since anybody can have same experience following that tradition. I have currently an RG article dealing with this issue, “Science and Spirituality are complimentary ----“

The well-treaded path for subjective investigation  mentioned above belongs to age-old Indian Vedanta Philosophy which any sincere seeker of Truth can pursue and experience himself or herself the state of “pure consciousness”. Numerous spiritual seekers (Yogis) of Truth as well as Armchair-scientists (like Albert Einstein and Richard Feynman) and Mathematicians (like farsighted mathematician Ramanujan) have experienced the state of pure consciousness and have expressed this singular experience in various distinctive ways due to a lack of analogy in our visible universe.  But none can define this unique experience to others due to lack of any analogy. It is like trying to explain someone the taste of a fruit that he never tested before. No matter how articulated I am it is impossible for me or anyone to convey the taste of that fruit to this person. The answer is “taste it yourself”.  

This question actually raises a number of issues that have plagued us for centuries. Not being able to define something though, tends not to prevent us studying it. Some (classicaly the behaviourists) have denied that conscious states even exist. And for a while their research programme still proceeded to generate interesting results (about other aspects of function, if not consciousness). There are aspects of consciousness (ie aspects of conscious experience) that while subjective, have been and are being studied successfully (eg perception, illusion effects etc). This doesn't tell us everything about inner mental life, but it does tells us something. And studies of cognition (eg attention, memory etc) are also successfully revealing other aspects of what previous generations would have considered subjective, inner and unknowable states. So my basic answer to the question is "maybe - but let's not hang around for it"!

Hi Wilfried!

Your question as I intepret it identifies two different , perspective-dependent kinds of definition, an ontogenic/ ontological one and a functional one.

Regarding an ontogenic/ontological definition i am not at all clear as to what benefit, epistemological or otherwise, such defining could offer: wouldn't any terms deployed necessarily be grounded in begged premisses, and hence tautological? If so, then, no, we don't need any such definition. Which prompts me to wonder (as others have): what exactly is the philosophical "Hard Problem of Consciousness" (which is ontogenically and ontologically concerned) Is it perhaps a pseudo-problem? If so, we'd surely benefit by ousting such attempted definitions.

As to defining consciousness from a functional perspective, I think that is a project of absolutely fundamental scientific and humanitarian importance. The whole domain of the intellect, mental skills, cognition, the status and practical value of perceptual knowledge, theory of expertise and its acquisition, of learning, of controlled vs automatic processing etc.etc. fall within the scope of such defining. Nowhere is progress in this direction more needed than in formal child education, where  a basic and constantly catered-for objective from the first day of schooling should be to nurture children's awareness of the means by which we understand the world and ourselves and so empower them.

Unlike ontogenic/ontological defining, functionally-focused defining is a feasible project. Key to its feasability is the insight that consciousness necessarily involves content - i,e. is conditional upon neural representations of encoded information as expressed at a certain (necessarily abstracted) level of processing. The functional defining of consciousness does not require understanding how those mechanisms work or why their products should be conscious states, but merely a consideration of what is represented and what kinds of processes are active at the moment of representing it consciously. A black-box methodology for determining the defining parameters of consciousness suggests itself to me as the most likely, and the only realistically feasible way forward. Consciousness is potentially definable, in functional terms, on the basis of identifying the input(s) that result in a consciously experienced representation and identifying the consequence (or general kind of consequence) of its output on the behaviour and/or (neuro)physiological state of the experiencer. Eventually, with a sufficiently large and broad-ranging database about  such events, commonalities might become observable, from which possible parameters for a functional definition could be proposed.

The previous answer and mine amount to more or less the same. But there is one caveat. It's possible that once we have a lot more information about what consciousness does (or at least what possessors of consciousness do) we might be closer to understanding the "it" that the word "consciousness" names. But I'm not so sure. I think this is to confuse levels of analysis, and possibly to conflate ontologically different things. Some philosophers argue that actually this is fuss about nothing (although John Searle and the Churchlands come at this from very different standpoints). Others have argued that consciousness (at least of others) is fundamentally closed to us, because we're trying to use consciousness to understand consciousness, and that can't work. I think there's general agreement, that there's lot to get on with, while we're trying to work this stuff out.

Dear Wilfried,

''It is not possible to prove consciousness because it is a subjective perception. ''

The question of the ''existence'' of consciousness is non-existent.  Doubting consciousness is like someone calling me on the phone and telling me that he doubt the existence of a phone!!!!  CONSCIOUSNESS IS EXISTENCE FOR US and anything that exist in the world apart from ourself exists as a modification in our consciousness content.  So ''consciousness'' is the only thing in the world which we do not need a proof because it is our existence and the its content is the condition of existence for us of everything else.  

'' We also are not able to express our inner states, for example when we precept the color of red. ''

YES and NO.

We can express a lot of aspects of our inner states and learning a language is learning how to do that and how to interpret the expression of other.  We cannot express fully all aspects of our inner states for multiple reasons.  Human languages are social constructs and they have been design to express what is usefull socially.  For example if you look at the snow and tries to tell someone what is the colour of the snow and that your language is English and both of you are European you will not achieve a precision equivalent to two Inuits whose language has 78 different words for different types of snow and associated experience in using this vocabularies.  Hawaiians have 65 words alone for describing fishing nets, 108 for sweet potato, 42 for sugarcane and 47 for bananas.  We should not assume that when an urban european look at the snow , his consciousness's content is probably not as rich than the consciousness's content of an inuit, so culture which include language is integral to consciousness.  The enculturation process of a person shapes the type of consciousness a person will have and the type of aspects of that consciousness that are expressable.  Languages and all forms of arts are possible because we can express and understand the consciousness state within a certain cultural context.  

Our culture trained us in being sensitive to certain aspect of the world and communicate about it but this very training hide other aspect of the world to us. A lot of problem in human relations come from the fact that we speak from within different culture and sometime because we learn a foreigh language.  Some realities are common knowledge in some culture and totally absent and invisible in other cultures. The problem is great given that our own culture is totally invisible to us in the sense that it is through it we understand, it structured our consciousness and what fit this structure can be understood and what does not fit it is not understood.  It is why so many human communication are failing.   Enculturation is the Structuration of our consciousness and since all culture is the result of an historical process it means that the structure of our consciousness embodied the structural history of our own culture.  So if we would be conscious of how we are conscious we would realize that we structure our  social understanding in ways that are parallel to our own culture structure itself.  There is an historicism structural dimension to consciousness.  Our personal consciousness is intrinsically a social consciousness and because of that communication which is intrinsically social is possible at even a deeper level that the our language because we can develop our own language when we feel the social need to do it.  

To your question: ''Do we need a definition of consciousness?''

Trying to define consciousness is trying to define who we are as individual and as a species. Trying to do that is tryin to know thyself and as I emphisized earlier ''Know thyself'' is also a ''Know thy history''.  Do we need to know thyself ?  Yes according  to the famous Delphic maximswas inscribed in the pronaos (forecourt) of the Temple of Apollo at Delphi. http://en.wikipedia.org/wiki/Know_thyself

I fully agree with Louis Brassard’s statement ''It is not possible to prove consciousness because it is a subjective perception.”   This subjective perception acquired in the traditional way is called “subjective science” since anybody can have same experience following that tradition. I have currently an RG article dealing with this issue, “Science and Spirituality are complimentary ----“

The well-treaded path for subjective investigation  mentioned above belongs to age-old Indian Vedanta Philosophy which any sincere seeker of Truth can pursue and experience himself or herself the state of “pure consciousness”. Numerous spiritual seekers (Yogis) of Truth as well as Armchair-scientists (like Albert Einstein and Richard Feynman) and Mathematicians (like farsighted mathematician Ramanujan) have experienced the state of pure consciousness and have expressed this singular experience in various distinctive ways due to a lack of analogy in our visible universe.  But none can define this unique experience to others due to lack of any analogy. It is like trying to explain someone the taste of a fruit that he never tested before. No matter how articulated I am it is impossible for me or anyone to convey the taste of that fruit to this person. The answer is “taste it yourself”.  

Tushar,

do I understand your above answer right that your opinion to my question is: "no", because it is impossible to define what consciousness is?

Wilfried,

Science cannot reach to the realm of experience, tasting an apple, experience colour, feeling pain in your finger, all that is beyond science.  It is not to say that science has nothing to say about what is going on in our body that support these experience.  But there is an unbringing gap between a 3th person view of what is going on in the body and experiencing as this body.  A third person scientific description is not about the experience but about what we can observed from the outside.  The first person experience is what exist for the person while the third person knowledge is what can be observed by everyone else.  The two perspective are different.  The first person perspective is not knowledge but what existence is while the third person perspective is knowledge/model of process in the body.  It is limited to different perspective that can be observed externally while the first perpective is not partial, is not knowledge but IS.  Science is not about IS but about model of aspect that exist as observed and it can only exist as a communication artefact of a community of scientist.  It cannot exist outside of it.

Louis,

no doubt, you are right and I agree totally with your point of view.

There is also no doubt if science do understand what is going on in a mind we can build an artificial model which is able to have experience like states. This is the challenge.

Wilfried,

Strickly speaking I do not think that ''we can build an artificial model which is able to have expererience like states.''  Here is why:

1.  A model is never strickly speaking identical with reality.  A model is an approximation of an aspect of reality.

2. Your and my consciousness are not a model, nor an approximation , but is what it is like to be me.  

3. A machine is the sum of its parts and this include software.

4. A humanoid robot is a machine design to operate in human-like environement to to perform human-like tasks.

5. A humanoid robot as above defined while acting in the world will have some internal states reflecting the state of its action in relation with its body and environment.

6. Can we say that a humanoid robot 's internal state that it is equivalent to our consciousness?  The humanoid robot has a body totally different than our body and its goals and purposes are very different from ours and so we can understand that their consciousness as defined as their internal state is very different from our consciousness.  But can we say that our consciousness is an internal state of our body?  If one answer yes then the humanoid is conscious in its own way.  

7.  I define the consciousness of my body as the dynamic nexus of its growth/learning of its interaction.  It is what construct the body from the time of its conception.  The whole body is thus a mirror of the interaction with the world that come to exist through  my conscious choices that built my life and body.  So consciousness is the constructor, As long as i build my life and body I am conscious, I am alife.  

8.  Can the constructor be constructed?  To construct something we need to know it.  Can we know consciousness?  My consciousness is where my attention is and this depend on the state of my body but I assume that the growth at the nexus of interaction is not a deterrmistic process but involve a radical emergence for the choosing of the direction of growth.    

9.  A humanoid robot that is not build through an irreductive growth is a zombie.  The state of the body alone is not sufficient for consciousness. 

I came away from reading Damasio's "Self Comes To Mind" vastly informed and with a clear and productive scientific perspective on the subject of consciousness. The book is a tour de force, wonderfully developed and thouroughly comprehensible, and I'd recommend it wholeheartedly to anyone at all interested in the topic we are currently discussing.

Richard,

what is so fascinating in Damasios book? My impression is not so euphoric.

Wilfried,

It was me who just endorsed Richard's appraisal of Damasio's book! I am also very much inspired by it. Read my essay on page 27 if you like.

Ursula

Wilfried,

What fascinated, inspired and educated me is that everything in Damasio's account makes reference to aspects that I can identify with subjectively. That is a far cry from works like Gerald Edelman's "Bright Air, Brilliant Fire", a book far too advanced for me to take in when I first attempted it. I came to Damasio's far more approachable book at the precise "critical period" that was right for me, and thus it inspired me.

I am not suggesting that Damasio has the last interesting thing to say on consciousness.- Edelman has a great deal besides. It is an intelligent beginner's. course, a bridge to further possible exploration and understanding. As I said, it sufficed to help me understand the rudiiments suffiiciently to make useful progress with. Damasio provided me with a meaningful account that worked - and still does work - for me as a solid grounding. 

Maybe in the course of time Damasio will be forgotten. As regards the scientific and technological means to investigate the mechanisms of consciousness, we should not forget we are in our earliest infancy of making progress after thousands of years of pure, irresolvable, and sometimes ludicrous speculation. As I said in an earlier post, there are some definitions of consciousness we can be pretty sure we don't need. There are some recent attempts that seem helpful. Then there are those yet to be offered, and until they are, we shall never know their value.   

I'd also state my opinion that no  theoretical account of any natural process or phenomenon has ever captured the "essence" of it  as an active, energetic entity. Why should we expect any definition of consciousness to be an exceptional case? If we do, should we discard all theories on the grounds of their sheer "Grauheit"? That would constitute the kind of radical skepticism that fascinated Descartes, and which has hindered scientific thinking about Mind and consciousness  down to our own time. 

Jose,

do I understand you right, that your example is an attempt to define conditions where consciousness is necessary.

This would be an approach for diagnosis of consciousness as we do to other persons. We do not know if they are conscious but their activity is a strong indicator that they are. If there is no clear counter-example, you could work with it. 

Hello Wilfred and all

I endorse Richard's endorsement of Edelman - well worth reading imho. But my perspective on this question is that unconsciousness is just as interesting and that the two cannot be separated - see Lakoff and Johnson's 'cognitive unconscious'.

When I was teaching McLuhan's Media - the extensions of man some years ago, the smartest comment I got was a female student who asked 'why are men so preoccupied with their extensions?' I mean no offense, but are we preoccupied with consciousness because its so obvious?

Wilfried,

While many of your responders have answered from perspectives that do not represent original products of their mental considerations of consciousness, but ones long-standing and thoroughly entrenched in our particular cultural inheritances, I would like to offer a home-grown alternative of my own, long in the making, and devised for the reason that those entrenched perspectives have never satisfied me intellectually or helped me understand the world - or address the challenges to my abilities that I confront as a musician - practically. The conclusions drawn from those perspectives are inevitably ensnared by their own premisses, and, regardless of the sophistication and beauty of the creative reasoning towards such conclusions, they cannot reach beyond their bounds to provide the forms of elucidation and erudition I myself have needed. My own following answer - extremely compacted - is of course, likewise ensnared by its premisses, which will strike some as willfully impersonal in character. Nevertheless, such premisses are ones that I can readily translate into personally meaningful and empirically fertile imagery.

My summarization assumes (1) that consciousness is necessarily "consciousness of certain things" and that consciousness of nothing implies unconsciousness; and (2) that as obligated exploiters of the content of consciousness, we can, on the basis of subjective experience, only define consciousness in functionally and contextually related terms - that is, in terms of the circumstances in which we exploit it, what of its content we exploit, to what ends, and how we refer to it and back to it in attempting to attain those ends. So to my account:

At any given moment, consciousness is defined by a variety of qualia that represent the outcome of sufficient structural processing by currently active subperceptual levels in early sensory cortices. It is at this perceptual level of primitive consciousness that higher levels of informational organization become able to infer the significance of the sub-perceptual activity to the individual's current needs or wishes. Cognitive processes that, through previous context-dependent learning, have formed long-term memory representations coupling a particular qualium with a particular need, are able to recognize, compare and thus decide which of the diverse current sub-perceptual sensory activity would be most advantageous to select as input for motor acts that satisfy the individual's state of need and to be given attentional focus while the duly-configured motor-act is attempted, and if necessary, reattempted. Since selective attention filters out unselected qualia, consciousness becomes duly re-defined.

Since the above process whereby consciousness becomes dictated by and subservient to a state of need is essential for the satisfying of needs, and satisfying of needs is imperative for survival, it is obvious that we - i.e. our brains ("we" being just one of its more complexly integrated sets of selected qualia) - need to define consciousness as a continual, moment-by moment occupation. Since healthy, intact brains consist of mechanisms that ensure such defining of consciousness happens inevitably, I'm inclined to think that any intellectual need to define consciousness  is entirely redundant. Except, that is,  for didactic purposes - as I noted in an earlier post, it  is vitally important for every individual to appreciate consciousness and its content in terms of its significant implications for his/ her (and others') aims, and not as mere decorative colouring of our existence that we can allow ourselves habitually not to pay attention to.

Jose,

Thanks for your question!

First, by "qualia" I am not referring to "thoughts" (the products of cognitive mechanisms and their operations), but to the phenomena we experience consciously either in direct response to sensory input (environmental stimuli) or as recalled images of previously experienced phenomena. Your experiencing of the sight of a chair, a dog, or a mountain is a qualium. Other qualia relate to other sensory modalities - a particular sound, smell, taste, felt texture, bodily sensation. In short, a qualium is any experienced entity that exhibits qualities of some kind. The classical notion of qualia, however, specifically excludes "internally" generated qualities that are associated with the experiencing of a phenomena, such as emotional feelings, context-related implications, goal-concepts, and ideas or thoughts that are triggered in response.

Secondly, qualia are composite re-presentations of sensory input, constructed over the course of several stages of non-conscious analysis and synthesis. Each pre-conscious stage of processing constitutes a more abstracted representation of the actually presented input from sensory end-organs. Stages of visual processing begin with a mere representation of the presence of certain stimuli; the second level integrates the output of the first so as to discriminate elementary features, which are then progressively synthesized by higher pre-conscious levels. Consciously experienced visual qualia represent the converging of processing by different sub-systems dedicated to representing shape, colour, location, motion, and spatial orientation of a given set of stimuli. Pre-conscious processing underlying auditory qualia is conducted in analogous terms.

To take the matter of qualia and conscious experience further, I can thoroughly recommend five of the short interviews from the following set (Ned Block, Joseph le Doux, Arnold Scheibel, Rodolfo Llinas, Alva Noe - watch in this order!)

What makes Brains Conscious?

I hope this helps!

http://www.closertotruth.com/series/what-makes-brains-conscious

What Makes Brains Conscious? | Closer to Truth

Thank you Richard for this highly interesting link! To me, I guess, it helps a lot!

As you might have read in my essay, for me consciousness and qualia are represented and made up by the multitude and variety of brain's waves and oscillations.

Ursula

A representation of sensory input is not enough for Qualia or consciousness. There must be a stable set of categories and their dynamic. There must be the coincidence of input and anticipation. 

Richard,

What you described is similar to what Susan Hurley called the classical sandwich model of the mind.

"1. The classical sandwich and how to resist it.

A familiar mainstream view of the mind has three aspects.

First, perception and action are seen as separate from each other and as

peripheral.

Second, thought or cognition is seen as the central core of the mind. The mind

decomposes vertically into modules: cognition interfaces between perception and

action. Perception and action are not just separate from one another, but also separate

from the higher processes of cognition. The mind is a kind of sandwich, and cognition

is the filling."

http://pacherie.free.fr/COURS/DEC/hurley.pdf

Louis,

what a funny metaphor. The mind as sandwich ...

Bon Appetit

Louis,

I wonder why you sub divide the mind in two (or more) parts. I thought your opinion would be the unity of mind and body (embodied mind). Why do you divide the mind in functional parts? What will be if you remove the bun - is there only cognition?

O.K. it was a metaphor. 

Well, there are some functional distinctions but there is only one mind.

Wilfried,

It was a quote from Susan Hurley paper.  She was critical of this way of looking at the nervous system: input (sense)--->processing(cognition)->outer action

If we simply take the example of touching a surface with our hand, the classical sandwich model of the mind does not seem to be applicable.  The impression we get from the touching of the hand seem to be intimatly connected to the active movement of the hand.  It does not seem that there is a clear input/cognition/action separation.

Hurley and myself think along the embodied cognition paradigm.  This is not a specific theoretical model but the name given to a large number of approaches which have in common to resist the classical sandwich model of the mind, a resistance to internally representing the world, etc... It began around the 1990's but all the ideas were old philosophical ideas that were forgotten for half a century.

Jose,

Animals have some imagination: young mammal play, all mamal and birds dreams.  But animals do not have those dream-like thought as we have.  When the lighting is low and the stimulus is ambigious, we often mis-interpret a part of a visual field for an animal which for a second seems very realm and the next second we realize it was simply a branch.  These are instances where we realize that imagination is part of the vision process.  The more you closely pay attention to your vision, and the more you realize that a lot that we think we perceive, we actually imagine.  Animals have the same type of imagination completing what is actually seen.  But human we are able to control this self-enact imagination and so create dream-like narrative while being awaked.  Our imagination is able to use narrative based sensory-motor system in a way independent of the actual stimulation of our sensory-motor system.  We are day-dreaming animals.

Louis,

"Hurley and myself think along the embodied cognition paradigm."

So do I. 

Jose,

emotions are an indicator for qualia.

Jose,

"babies (by observation!) are full of qualia"

Yes, but they do not understand what they perceive. The babies do not have categories of perception but they are working to build them.

Qualia. I see this term in this thread repeatedly. It bothers me. With Nagel, I agree that there is something(s) it is like to 'be', in the sense of being conscious, and something it is like to experience the color red or the fragrance of a rose. But I worry about what is implied by the use of the term here, in terms of  philosophical baggage. That is, in the Embodied Cognition community there are positions which I, along with Chemero, identify as retrogressive, or 'closet' Cartesianism.

Simon,

that' interesting.

Wilfried,

if you don't know it, I think Chemero's Radical Embodied Cognitive Science is a good synopsis. He is coming from a Gibsonian position and proposes a theoretical armature based on an updated, relational  Gibsonian ecological perspective.

Simon,

I just read the abstract of the book by Chemero.  I am very familiar with Gibson's approach and I now consider it as a low grade version of Von Uexkull theoretical biological position.  When one adopt an evolutionary biological interactionist position has to be primarily based on action.  It is why von Uexkull is the for-father of ethology: the study of the behavior of animals.  

Part of the puzzle of the fact that we cannot specify in any language what the feeling of red is.  Humans when they invented that word, did not worry that one of them might see blue while everybody else see red.  Those type of thinking game was a sport.  It was implicitly assumed that all of us perceive colour the same way.  And parents teach the word ''red' by pointing to a red object and repeat this a few time and the job is done and there is no metaphysical problem that arise from this. Language are invented to communicate effectively.  Now when we come to try to explain colour perception and to explain what is this red qualia, this what is like to see red, we cannot answer such question with science.  A what it feel like is not a scientific question. It exists but science does not investigate existence in general.  It only investigate relations between measurables.  Everything outside of that is outside of science as a method of investigation and expression of knowledge.  It is not a hard scientific problem, nor an easy scientific problem , it is not a scientific problem at all.  One would need to invent a experimental phenomenology which would extend science .

Louis,

I am also a great fan of von Uexküll, but I would not say Gibson's work is  "a low grade version of Von Uexkull theoretical biological position".

"...science does not investigate existence in general. It only investigate relations between measurables. Everything outside of that is outside of science as a method of investigation and expression of knowledge. It is not a hard scientific problem, nor an easy scientific problem , it is not a scientific problem at all. "

well said.

"One would need to invent a experimental phenomenology which would extend science"

What do you mean by this? Isn't what Husserl did? And which , in English, Don Ihde  (Experimental Phenomenology) has done a good job demystifying?

SP

Simon,

The more advance phenomelogue are the artists. They have too.  They learn by practice and most of their learning is not theoretical but intrinsic sub-conscious know how that developed by experimentation.  Visual scientists would learn so much if they would survey all the know how of the visual artists in the different visual arts.  What works in the cinema, in the animation and video games, what does not work.  Eventually the vision scientist should venture and following his insight and create new visual art techniques, new mode of expression.  Work primary on the artistic side as a way to explore its theoretical intuition.  He should monitor his vision and action with appropriate technology. Research should become a mode of self-exploration.  Even studying fiction should be fundamental for discovering the core archetypes of action narratives.  It seems to me that very little is done yet.  

Hello Louis,

" They learn by practice and most of their learning is not theoretical but intrinsic sub-conscious know how that developed by experimentation. Visual scientists would learn so much if they would survey all the know how of the visual artists in the different visual arts. What works in the cinema, in the animation and video games, what does not work."

Speaking as someone who has straddled the art-science world for decades, I have a complex reaction to your recent post. I am impressed by your respect for what artists do. The art-science relation is often characterised by hubris in both directions.

(see my Rigorous Interdisciplinary Pedagogy:

five years at ACE 

http://simonpenny.net/texts/rip.html)

"Eventually the vision scientist should venture and following his insight and create new visual art techniques, new mode of expression. "

This I think is the part that bothers me. At every level from cognitive scientists to software engineers I have heard this argument. But there are two (at least) problems with it. Many artists do not want 'technicians' to develop new 'tools' for them so they can do their art 'better'. And  in the art world (self) 'expression' is regarded as an anachronistic modality for art. Many theoretically sophisticated artists will think it naive and put in in the category of 'art therapy'.

Now this passage, on the other hand, is very stimulating and makes me think of Andy Pickering's work on the British Cyberneticians.

"Work primary on the artistic side as a way to explore its theoretical intuition. He should monitor his vision and action with appropriate technology. Research should become a mode of self-exploration. Even studying fiction should be fundamental for discovering the core archetypes of action narratives. "

see for instnce his New Ontologies paper at

http://lifeboat.com/papers2/andrew.pickering.pdf

best!

Simon

Dear all,

Merry Christmas to you and a happy new year.