Complexity Seminar, 5 December 1998 - 1998 - 1995 to 1999 - Events - LSE Complexity Group - units - Research and expertise

Dr Jack Cohen is an internationally-renowned reproductive biologist, who has been a consultant to a number of fertility clinics. He currently works in the Mathematics Department at Warwick University, exploring issues of complexity, chaos, and simplicity with Professor Ian Stewart. Dr Cohen has written many books, both factual and science fiction (see Bibliography), as well as numerous research papers. He has also advised top science fiction writers on designing credible creatures and ecologies. His latest science fiction venture is The Round World Project, a collaboration with Professor Stewart and Terry Pratchett, author of the popular 'Discworld' science fantasy series.

Dr Cohen gave the keynote speech which concluded OACES. In it, he drew on his collaborations with Professor Stewart to provide insights into how an understanding of emergence and the complicit interactions between intelligence and culture can help to explain how beings as complex and adaptive as humans evolved from much simpler life forms.

This report was edited by London-based Editorial Consultant Malcolm Peltu, using material from Figments of Reality (Stewart and Cohen 1997) to fill out some areas Dr Cohen did not have time to cover in his OACES keynote talk.

Nature's strange ways

In the 1970s, Art Winfree and I developed an instructive game for demonstrating something which seemed to break the 'laws of nature'. It is based on the Belousov-Zhabotinskii (B-Z) recursive reaction. For this, we developed a mixture consisting of an oxidising agent and a reducing agent, together with a dye which goes blue when oxidised and red when reduced. This sets up a cycle of alternating oxidisation-reduction changes which cause periodic colour changes as the chemicals organise themselves. At first, the liquid is uniformly orange-brown. Suddenly, little blue points start to appear because of random events in the liquid. The points spread like a forest fire, changing colour as they make a pattern of expanding concentric red and blue rings. Like a forest fire, the reaction can't go back to where it has been, so must proceed in one direction once it gets started.

The second law of thermodynamics says that chemistry must go downhill. In this case, it is going down hill in a series of steps, where the riser is red and the tread is blue, as it cycles recursively through the same sequence of changes when the reducing agent oxidises and the oxidising agent reduces. Chemists disbelieved this kind of reaction for many years because it seemed to produce its own order and organisation out of disorder, which apparently contradicted the second law. Yet far from breaking any natural law, this kind of self-organisation into emergent phenomena is essential to understanding how life on earth evolved ¾ as advances in our knowledge through disciplines like Complexity Theory now clearly show.

Processes such as the B-Z reaction also seem disturbing because of the chicken-and-egg problem: it is difficult to understand how they ever start. Nevertheless, biologists have developed some pretty good ideas about the way life got started. It seems that the cell arose by a process of symbiosis involving various kinds of independent bacteria. In other words, cells emerged from the coevolution of bacteria. Such emergent phenomena form systems characterised by behaviour that appears to transcend anything that can be found in its components. The B-Z demonstration is one example of the natural world's numerous ways of surprising us and changing our preconceptions about it.

Life on earth depends on molecules bound by carbon atoms. The organisms we call 'life' might, in principle, also arise in other ways, say from silicon-based molecules or trains of electrons in metallic crystals. The idea that our own life forms might seem to be peculiar from other perspectives is the theme of a book I recently wrote with Ian Stewart and Terry Pratchett, author of the popular Discworld science fantasies (Pratchett et al 1999).

Discworld is a flat planet. It sits on the back of four giant elephants, which sit on the back of a star turtle called Great A'Tuin. In our book, the wizards of Discworld's Unseen University are making a universe. When the money runs out, they moan: "How can we be expected make 100 elements out of nothing? You are going to get a very cheap universe in which a third of the elements will come to bits. They won't last. We have none of the Discworld elements which go to make proper flat planets. So we will have to make the thing round. That means it will get hot in the middle, the bottom of the sea will crack, the continents will wander all over the place …"

You don't have to be a wizard of the Unseen University to think that life on earth turned out a bit strange. That life emerged from the sea. A fish was our ancestor, and that of the amphibians, reptiles, birds and other mammals. Swimming in that sea were a great variety of other fishes, some of which also made adventures to come out onto land. A characteristic of the one which became our ancestor is that it crossed its air way and food way. That's the best argument against creationism: no engineer would design a system like this. There were lots of fish in the primeval sea with dorsal lungs that allow separate breathing and digestion systems. It just happened that the one which succeeded, for all kinds of accidental and other reasons, had an air way crossing its food way. Another big design fault is that it mixes its excretory system with its sexual system. One of the consequences was that when some of its descendants invented books, some of the books were dirty books. If a different fish had first succeeded in moving out of the water, perhaps people wouldn't have thought sex was dirty.

The Grim Sower's evolutionary arithmetic

One of my basic interests as a sperm biologist is why which so many sperm are offered at a time, typically 200 million. This kind of profligacy is also reflected in a reproductory arithmetic among animals which should change some traditional views of biology. Take, say, the population of starlings around Warwick. It is currently more or less steady, going up and down by no more than about 10%. A female starling on average lays 16 eggs in her life. Only two of these go on to breed. This means a pair of parents in one generation makes a pair of parents in the next generation. For every pair of starlings that breed, 14 die. A female frog typically lays about 10,000 eggs in her life. Of those, 9,998 die before breeding. A female cod lays about 40 million eggs in her life, of which 39,9999,998 die before breeding.

Nearly all wild creatures actually die without ever breeding, mainly by becoming food for other creatures. This indicates that the ecology is a necessary part of reproduction, and the cod and frog and sparrow are necessary parts of the ecology. That speaks of a Grim Sower, as well as a Grim Reaper. The Grim Sower highlights why Maturana and Varela (1988) got the biology of reproduction amazingly wrong in their writings about autopoiesis, although a lot of other things they said are very clever. They think that reproduction is two parents producing two parents. It isn't. Reproduction is an acorn making an acorn, an oak tree making an oak tree ¾ and producing 100 million acorns in the process. It is a system in context in an ecology.

I want to go back to biblical time for an illustration of how context affects evolution. The Judeo-Christian philosophy has some reproductive biology in all those biblical 'begats'. We now know that the Cohens are really the descendants of Aaron. But there is an interesting question about why too many of us have Aaron's chromosomes. There is about 95% correlation in most societies between biologic and legal paternity. In our society, about 1 in 7 people don't know who their father is; among a tightly-knit community like the Amish it is about 5%. There is a hundred generations from me to Aaron, and if we assume my ancestors in this time were only 5% 'naughty', then there ought to be only less than 1% of Cohens with Aaron's chromosomes; in fact there are 70%. My suggestion is that women 'sin downwards' for sex and 'sin upwards in status' for having children. And if you are a Cohen, the only people you can go upwards to are other Cohens!

Where does the human mind come from?

As I biologist, I find it puzzling that creatures which were evolved for living out on the savannah ¾ perhaps living on seashores, perhaps shouting at each other and gossiping with each other ¾ could end up producing our kinds of brain, which can do algebra and invent jumbo jets and much else. It seems odd that a biological brain, by the ordinary processes of evolution, should be able to do so much more than it is required to do. You don't find that a fish, like a tuna, which developed to swim very fast eventually ends up flying and doing algebra.

It is easy to imagine how following an evolutionary instinct can generate a great variety of creatures. The difficult question is: 'What kind of journey made it possible for inanimate matter to turn into complex creatures like us, with selves, which can look at themselves, think, got to lectures and have their own inner worlds of mind and imagination?'. I would like to focus on answering this, as Ian Stewart and I did in greater depth in Figments of Reality (Stewart and Cohen 1997).

The self-organisation and emergence demonstrated by the B-Z reaction are vital concepts in helping to understand the origins of the human mind. Emergence occurs when low level rules generate high-level features. However, the self-organising ability of life becomes clear only over long time-scales: from atoms to molecules; from a rock to a mouse; from our first amphibian ancestor to you and me.

Many animals have brains, but few appear to have minds. A mind is a higher level of organisational complexity. In The Collapse of Chaos (Cohen and Stewart 1994), we introduced the concepts of simplexity and complicity to help explain our view of complex systems and their interactions. Simplexity is the tendency of a single, simple system to generate highly complex behaviour. This leads to the more subtle concept of complicity, which is when two or more systems interact in a mutual feedback that changes them both, leading to behaviour that is not present in either system on its own. This is also a characteristic of emergence through coevolution.

Humans are good at both thinking and doing. I have discovered the importance of this during more than 30 years as a theoretical and practical biologist. My field of reproductive biology has reached an advanced state of development, with lots of new ways of 'making people' using relatively good technology. In 'test tube baby' clinics where I am I consultant, I have seen that fertilisation involves about 60 processes, each of which requires 8 to 12 things to be done exactly right to achieve the required result. It isn't simply a question of mixing sperms and eggs together. We are getting good at doing this because we are good at thinking and doing. In a long life I have discovered that one way of getting good at 'doing' is to make lots of mistakes. I love mistakes to death, and was once goaded at a science fiction convention to invent Cohen's Law: 'Unless you fail at more than 10% of the things you try, you aren't trying enough things.'

Another things humans are good at is being able to see more than one way of looking at something, just by thinking differently. A lovely example of this was a sign I saw recently at Neufchatel railway station, on the way to a systems conference:

Objects Trouvé

Lost Property

The French for 'found' objects was taken to mean 'lost' property. I would now like to show how this ability to find another way of thinking about things can be applied to our ideas about evolution.

We are not our DNA made flesh

By and large, biologists nowadays tend to do things largely related to the notion that DNA is in the driving seat of evolution. This view has been popularised by 'neo-Darwinians' like Richard Dawkins, who has written so well and so persuasively about 'the selfish gene' (Dawkins 1989). Nevertheless, the belief that there is a mapping from genes to character, from a genome to a phenome, is nonsense: there are no genes for a hand, for example. Yet the notion that I am my DNA made flesh has pervaded everywhere. I am one of the many biologists who don't espouse this rather simple minded view. If you slice up my chromosomes you don't see Jack Cohen. A certain amount of what you are may be 'written in your genes'. But an awful lot more is not, like almost everything that is of real social and cultural importance.

DNA is not self-replicating, although many people believe it is. If you leave a mass of DNA in a beaker, you won't get more of it. The information in DNA is useful not because it is information, but because its information is stored in a form that other chemical machines can manipulate. DNA needs an entire support system to be able to replicate.

The neo-Darwinian viewpoint suggests that evolution happens through mutations, where good mutations go on to breed more and bad mutations die or breed less. That is wrong. You don't need more mutations for most evolution: we already have lots and lots of variety. Most change happens when there isn't much change in the genome; most genome change happens learning to live with a new way of life. The processes of evolution and mutation are simply dissociated. So, we need another way of thinking about evolution. I want to suggest why we should start to look for that in the nest.

From the nest to society: another way of thinking about evolution

The transition from brain to minds started when animals came up with tricks that opened up non-genetic routes to protect their offspring against the ravages of the Grim Sower. Babies are unlikely to thrive on their own. So, gnus, guinea-pigs, giraffes and other animals kept their babies inside until they could fend for themselves. As this imposed great strain on the mothers, some animals invented nests, where babies can be born premature and then protected. Mammals are among the best examples of animals which developed this kind of trick, which meant they needed to have fewer offspring. The young of such creatures were privileged by being given special protection at the parent's expense. This privilege afforded by parental protection gradually led to a new kind of intelligence, involving the new important tricks of learning and teaching.

Babies and parents form very close-knit systems. When a human baby throws an object on the floor, it will reward the parent with a smile when the object is picked up and returned, as part of the game of training Mummy to pick up and returns toys. Some other species who developed nests, such as otters, cats and dogs, have similarly exploited this kind of process to help their young learn tricks, like new ways of catching fish or scrounging food from people. There can be trial and error without penalty in the nest, which is why the appearance of the nest was an important step in evolution. The nest made it possible to get things wrong without dying, which is very important according to Cohen's Law of Mistakes.

Looking at this kind of cultural transmission of behaviour types is the only way we can properly understand how the human mind has evolved. Mind isn't just a matter of sophisticated brain structure. The cultural context that passes on tricks through learning and teaching is crucial, particularly for the most important and apparently unique features of human beings: imagination, creativity, and morality. These are all emergent phenomena of the complex processes of culture and evolution and cannot sensibly be traced back through a series of gradual steps leading from DNA, or any other simple precursor.

The privileged upbringing of a nest is relatively rare among animals. For example, the gnu is born knowing what a wild dog looks like and how it differ from its mummy. Baby gnus don't have to learn these things because their intelligence comes from internal circuitry they are born with. The learning cultivated in the secure environment of a nest is far more flexible than genetics in passing things between generations. It also has a much shorter response time. This creates a straight path from nests to human society. It explains why DNA molecules or chromosomes cannot explain how, say, my son Dan grew from a gurgling baby to become the Hewlett-Packard engineer and systems theorist he is now. That wasn't implicit in his DNA

The evolutionary significance of extelligence

To summarise where I have got so far: Evolution is a self-modifying game in which there is complicity between the rules and the overall state of the game; organisms learn to play the game while the game itself is changed by their moves. We carry with us the results of previous evolutionary actions, so that the complex strategies evolved by millions of previous generations can be written into, or out of, the fabric of the planet ¾ instead of the fabric of the genes. Complicit systems are organic because they involve recursion which feeds off itself.

One of the universal features of complicity is that it results in emergent phenomena of patterns, rules, structures and processes which were not present in the separate components of their coevolution, even in rudimentary forms. This is abundantly the case in the complicity between language and intelligence, which results in the collective experience of a 'tribe' becoming a cultural lexicon stored in the people that surround, and interact with, each child. This what Ian and I call extelligence. We believe the concept of extelligence opens a new view of the role of DNA in evolution. Instead of swallowing the seductive and popular image of DNA as a kind of blueprint for an organism, the genome DNA sequence for an organism can then be seen more like a partial recipe. In order to produce the things which end up as us, you have to add extelligence. 'Learning games' in the nest are one way in which babies insist that parents give them extelligence to tell them about the world.

Answers to the question of why humans are here, doing the kinds of things no other animals do, are usually answers about 'here': the environment where you find yourself. I want to give an answer which is more about 'you', as a member of a species that is a totally different kind of thing to other species because we have a trick that other species don't have. It is very difficult to see what that trick is because our notions of history have been so influenced by things like the Flintstones. When we consider the origins of thinking in the stone age, we tend to imagine one person invented fire, another invented the wheel, someone else invented laughter, yabba dabba doo! It wasn't like that at all.

What humans have which is different from all other creatures is extelligence. That is something other than intelligence. In the way that PCs have 'Intel inside', we all have 'intelligence inside'. But we also have 'extel outside': the cultural capital that is available for us to use in the form of legends, nursery tales, books, conference papers, videos, CDs, web sites, and so on, and on. Extelligence makes no sense without intelligence to interact with it; the two are complicit. Extelligence cannot get going without intelligent individuals to create it and respond to it, and creatures can't become intelligent unless there is something to be intelligent about. The intelligence of each individual allows them not only to access the cumulative body of extelligence, but to add to it or change it.

Our minds coevolve with everything that influences them and which mutually modify each other at every step, through feedback from each other. The developing mind of a child interacts with extelligence through language, and the two-way flow between individuals and their surrounding culture changes both. Intelligence is fostered in the child and extelligence is fostered in the culture. Thus, the evolution and structure of the brain cannot be divorced from the evolution and structure of human society and its environment. Language and writing are also inextricably linked to the development of culture and, therefore, extelligence.

Our definition of extelligence is different from other general concepts of 'culture' as a kind of passive tribal archive. Instead, we look at the external influence from the point of view of its interaction with each complicit individual. In contrast, most animals are one-man bands which conduct their own development. Seeing extelligence as functioning in both directions opens up the possibility of evolution, and makes it worth inventing a new word to describe it. Extelligence has a characteristic structure and behaviour that enables the knowledge of generations of intelligent beings to be accumulated, while constantly modifying and organising itself through continuing interactions with innumerable individuals. This process has made extelligence greater, more permanent, and for more capable than any individual intelligence.

The Make-A-Human-Kit

Neo-Darwinianism focuses on organisms competing for how many progeny they pass their genes to. Our alternative theory involving extelligence emphasises how parents provide offspring with a head start, and how siblings compete for the privilege of growing up. The nest allowed the development of a 'Make-a-Human-Kit ' through the extelligence contained in the stories, ideas and other social learning we transmit to our children, say in the way Little Red Riding Hood has helped to give many people similar bad feelings about wolves.

Make-a-Human-Kits are derived from patterns which have universal similarities in all cultures, but with enormous parochial differences. They allow our offspring to pass through a succession of experiences that result in the kinds of adults who support the society that produces further human beings. The kit has been effective because it is flexible enough to keep evolutionary change going successfully, but not so flexible as to make it difficult to pass it to the next generation. Children brought up by animals are seriously disadvantaged because they are deprived of the cultural framework of a Make-a-Human-Kit.

An important way in which we build our mind is through the icons which permeate our cultures, such as the way animals are universally used to represent character. There is great variety in the meanings of these animal icons because different people involve different extelligence, different interaction, and different evolutionary recursion. For example, the extelligence of our culture has led us to think about foxes primarily in terms of two words: 'sly' and 'cunning'. A fox isn't either of these. An Inuit audience would actually think of a fox as being 'brave' and 'fast'. A Norwegian audience would think of a fox as a 'secretive', in the sense that it is a creature to whom you would want tell your secrets, and who would advise you on them. Different cultures have different iconic foxes which their children learn about.

Nursery stories and folk tales are important ways in which a society's Make-a-Human-Kit teach us to associate foxes with slyness. Similarly, we have learnt that owls are 'wise'. If we see a picture of baby owls whose appearance makes them look completely daft, we are thrown because the reality is totally different from the icon. Our minds, therefore, often get things wrong. The way we build minds doesn't come with a guarantee. We often get things wrong when we use animal images as icons of character, as in the depiction I have seen of a financial situation, in which bears are supposed to be cautious, bulls adventurous and stags speculative.

Extelligence can also shape our perceptions through well known narrative imperatives. For instance, a cartoon showing three princes seeking a princesses' hand with the caption 'Andrew is hesitant remembering his fiasco with the car of straw' derives its humour from two narrativian themes. One is likely to lead you to expect the next thing to be a car of bricks, because straw-wood-bricks is a series in the tale of three little piggies and a big bad wolf. There is also a narrativian 1-2-3: the first king's son, the second king's son, the third king's son. The first shows it is possible to fail; the second tells you what the problem is; the third gets it right.

A reductionist's nightmare

Our alternative to Neo-Darwinism emphasises the way a system is shaped by the circumstances in which it operates, or in which it has come into being. This contextualism contrasts with the reductionist conventional scientific viewpoint that explains a system's function by breaking it down into its fine-grained components and showing how they fit together. Contextualism will not replace reductionism, which has been very successful in its own sphere; but there are many other spheres where a contextualist viewpoint is needed.

The reductionist's view starts with nature as a whole at the top, then you discover what nature is like by mapping into lower levels of detail. Such conceptual maps of the reality around us are drawn to enable us to take decisions and change our minds because it can help to explain how things fit together, for example why gravity makes the moon follow a particular orbit and why the apple falls. Discovery and explanation are distinct paths in this model. As human beings have produced extelligence, we have created bigger and bigger reductionist maps. Some physicists even picture a convergent system at the bottom: a 'Theory of Everything' which will unify all the phenomena of the physical world into a single fundamental equation, which can then be reproduced on a T Shirt for all to admire.

Although a search for a Theory of Everything might be intellectually satisfying and give us a better understanding of subatomic physics, it will hardly explain anything else of importance about the world, let alone everything. Even the concept of a T-shirt cannot be properly explained in terms of the physical structure of its cloth alone; it can only be explained by also taking account of the cultural context in which it has a role in covering bodies and displaying cute or humorous phrases.

Consider a problem like insulin-secreting cells. If I go to someone who knows about cells secreting things, she could say :'I can tell you certain things about your particular problem, but you should also talk to some chemists as chemistry underlies all this.' I could then find I need to talk to not just one chemist, but at least three specialising in different aspects of cell secretion. Then the chemists may tell me they can only go a certain distance in explaining the basis of cell secretion because a lot of physics is also involved. That means I have to talk to four or five different physicists who understand their particular segments of the whole picture. This process multiplies into a reductionist's nightmare because you need more and more specialists the further you go into understanding something.

Explanations do not simplify on the way down into detail, although they do simplify on the way up through emergence. My particular 'nightmare' example came from addressing a relatively small, simple problem about insulin and cells. Just think how much worse it becomes when looking at bigger questions, like how the universe began. That is why Ian and I argue that reductionism is contrary to experience.

Escaping from the nightmare through Ant Country

As the reductionist's nightmare marches into ever finer detail, its branches ramify indefinitely as it seeks in vain to try connect the everyday world at the top to the Theory of Everything which allegedly lies at the roots of all understanding. Making that connection is so complex that it is beyond human comprehension, so will never be done. Even Complexity Theory is unlikely to be enough, with its modelling of complex systems in terms of more or less simple interactions between very large numbers of more or less simple 'agents'.

Our ability to understand the universe can be likened to a chess game. You can know the first few moves and the end games really well. But all the stuff in the middle is so complicated that there a lot of intermediate positions where even a grandmaster wouldn't be able to tell who was winning. To do that, the grandmaster would have to know the plans and other things in the minds of the players, which are independent of the positions of the pieces. Ian and I call the complicated bit in the middle 'Ant Country': the gap between the bottom-up reductionist Theory of Everything and top-down reductionist's nightmare. Virtually all of nature's patterns are emergent phenomena generated from lower-level rules ¾ and all paths leading from patterns to the rules pass through the uncharted territory of Ant Country.

The behaviour of 'Langton's ant' illustrates how a path can be threaded through this tangled land. The 'ant' is actually a cellular automaton which lives in a grid of squares that can be either black or white. It moves through the grid following simple rules which determine the colour of a square and where the ant goes next. At first the ant keeps returning to the central square. Then the picture becomes chaotic. But eventually, as if it had finally made up its mind what to do, the ant builds a 'highway' that follows a sequence of precisely 104 steps. The only rigorous way we know to deduce how this large-scale feature emerges from the low-level rules is to write down the ten thousand or so steps that lead to the 104-step cycle.

Langton's ant is an example of simplexity because the ant's simple rules produce surprising complex behaviour. The way it builds a highway is a mathematical reproductive cycle which challenges sciences' claim that its bottom-up rules explain the top-down behaviour of nature. There are many examples of this in nature, games, and other things.

Keeping the evolutionary snooker break going

We don't know what difference seeing pictures of naked people make to someone's sex life. When I was growing up, it took a lot of work for me to find out what a naked young woman looked like. But now you can pick up a magazine or watch a video or TV to discover that our ways of transferring sexual expertise have been substantially changed, without any testing. This process of change without testing is usual in human society. My own paradigm is Fiddler on the Roof, in which all kinds of things are changing in a ghetto society because of wars, new technology, and other factors in the outside world that disrupt the ghetto's traditional way of life.

Now that we all live in changing societies, the key problem is to keep the snooker break going through good positional play that assists you to make the next pot. The evolutionary snooker break which has produced what now constitutes an Irishman, a violinist, a complexity researcher or any other human personality has been kept going for generation after generation, ever since the first crazy mixed-up fish slunk out of the ocean. Compared to this, reproducing the physical body is relatively easy.

What passes across the generations to reproduce, say, a violinist is only partly to do with DNA (Cohen 1977). A violinist could be created out of lots of different kinds of DNA. You also need all the cultural things with which DNA can interact in a variety of ways. Human beings are different from other animals because we have the extelligence of accumulating culture, as well as an in-built intelligence. When you change the extelligence, you have new knowledge.

We are much further advanced than the ancient Egyptians. I think we are a different kind of animal now because we interact differently to the way we used to, but not because there has been any intrinsic change in our biology. If you put us back in the stone age, with stone age people, we would behave like they did. And if you placed a stone age child among the Inuits, he would grow up believing that foxes were brave and fast because of his interaction with Inuit extelligence. So, when he sees the aliens at the bar in Star Wars, he wouldn't regard the foxy one as untrustworthy, he would think: 'I would go to that foxy-looking one if I were in trouble.'

Multiplex thinking for a multicultural future

The atoms making up the earth today are the same ones that were present four billenia ago, and humans are made from the same billenia-old atoms as rocks, water and air. It is not the ingredients which differ, but how they are now organised into much more diverse and complex molecules, some of which can perform the sophisticated tasks we call 'life'. The journey from the first carbon-bound molecules of life to modern man has been accomplished only through complicity with an extelligence that goes beyond individual intelligence by the enmeshing of the stories, knowledge, and culture of generation after generation.

Space travel provides a wonderful recent example of emergence. It once seemed that inescapable laws of physics and rocket technology determined the sum you would have to do to work out how much energy is needed to send a man into synchronous orbit. Then somebody invented the space bolas. A bolas originally consisted of heavy balls linked by a cord, which was used in South America to hurl at running quarry. Once money has been spent sending up a bolas space launcher, it can hurl more bolas pairs into orbit ¾ at a total of between a 15th and 25th of the energy needed if you were still using your 'inescapable' rocket sums. The Canadian-US BOLAS (Bistatic Observations with Low Altitude Satellites) project is planning a 2001 launch of a spacecraft based on the same 'cartwheeling missile' concept used by gauchos.

The greatest step so far in our cultural evolution has been the aggregation of different cultures to make multicultures. Today's multicultures are like the creatures of a colony, coexisting as more or less in isolated ghettos. If tomorrow's multicultures are to be more like genuine multi-cellular organisms, such as the tissues of a complex animal, rather the kind of competing multicultures which have caused turmoil in the Balkans, then we must order our perceptions to become what the science fiction author Chip Delaney (1966) called 'multiplex thinking'.

Multiplex thinking is typified by answering a question like: 'What is the most important thing in your world?' by saying something like: 'The following things are the most important ones for me. However, I have reasons to believe that others would have different arrays of important things, for perfectly good reasons.' The multiplex mind can work simultaneously with several conflicting paradigms and is comfortable with a mutable, adaptive, loosely coherent flux. Delaney contrasted this with two traditional way of thinking. He said 'simplex thinking' is to give a single answer to the 'What is important in you world?' question, while 'complex thinking' would be to respond: 'It depends. Sometimes its sex; sometimes its food; sometimes I want to know an answer to a question; sometimes I want to do other things.'

Complex thinking perceives many intertwined strands of cause and effect that combine in some kind of consistent worldview, which is roughly where we are today. We could afford to be simplex in the 1920s when it was still easy to put together coherent political majorities, before societies were fragmented into many minorities. We need now to move from complex to multiplex thinking if we are to break from today's competing cultures. Then, we will have a chance of creating new global multicultures that are like a coral reef: an ecology of interlocking species which all fit together, support each other, and are rich in diversity.

Bibliography

Cohen, J. (1977), Reproduction (London: Butterworths).

Cohen, J. (1989), The Privileged Ape: Cultural Capital in the Making of Man (London: Butterworths).

Cohen, J. and Stewart I. (1994), The Collapse of Chaos (New York: Viking).

Dawkins R. (1989), The Selfish Gene (Oxford: Oxford University Press)

Delaney S. R. (1966), Empire Star (New York: Ace Books).

Maturana, H. R. and Varela F. J. (1988), Tree of Knowledge: Biological Roots of Human Understanding (Boston: Shambhala).

Pratchett T., Cohen, J. and Stewart I. (1999), The Science of Discworld, London: Ebury Press

Stewart I. and Cohen J. (1997), Figments of Reality (Cambridge: Cambridge University Press)