Just what is science anyway?

In 1633, Galileo Galilei, the greatest scientist of his age, indeed one of the towering figures of all history, was summoned to appear before the Inquisition in Rome, the dreaded Holy Office. The Church suspected him of heresy. Today, it is hard to imagine just how serious a crime heresy was, but it is fair to say that it was then regarded as far more serious than murder or that favourite bête noire of the modern secular state - treason. It was, I suppose, treason of a sort, but treason against God. And the punishment was only fitting - to be burned at the stake.

And what had he done? He had shown scientifically that the earth must rotate about the sun and not vice versa. More importantly, for this theologically inconvenient fact has been known since the time of Copernicus a century before, Galileo had published his ideas not in the Latin accessible only to the ruling classes, but in common Italian and thus available to all who could read. Today he would have used the World Wide Web!

Galileo's prestige saved him from the stake. He wisely retracted his statements and spent the rest of his years under house arrest, even if, after his recantation, he made a larrikin, but sotto voce rejoinder: 'Eppur si muove' - 'But it does move'.

Galileo's trial was the most notorious episode in the continuing battle between religion and science: it was essentially an argument about the degree to which the church would concede to science the power to interpret the world.

I tell this story to make the point that science was a problem for our ancestors. They struggled with the issue of what to do with science, on the one hand, offering so much power to control the world, on the other, offering so much trouble to those who wish to control the world.

I also tell it to make the point that things have not changed much in the intervening three and a half centuries. Indeed they may have become more acute: science now offers undreamt of power in controlling the world, but it also offers those who seek control unimagined trouble and strife. Science has encroached, it has spread, there is no part of our world that this thing called science does not offer an argument on.

So the main purpose of my talk is to look at just how science relates to all the other things we humans do, and to see why it is still such a problem today. In doing so, I want to demonstrate perhaps the most important thing there is to know about science: science is not important because it is useful, rather it is useful because it is important.

To see this, we must first understand just what science actually is. And to see that, I perhaps should make a few comments about what science is not.

First, science is not the truth. It is rather a body of knowledge about the world and a recipe for growing that body of knowledge and a bunch of people busying themselves with that knowledge and that recipe all mixed up together. In today's computer-literate world, we usually call such recipes 'algorithms' or 'programs', and the knowledge 'outputs'. But it is important to realise that science is neither just the algorithm nor the output, but the whole lot including the people. It is also important to realise that we can push this analogy too far, that science is a special mix. Each part can change the other. The knowledge can change the recipe, the recipe can change the people.

I need to make it clear that this recipe is not what is often called 'the scientific method' - the approach used by most scientists since the seventeenth century. It is instead a recipe for discovering 'the scientific method', and all the other methods that achieve the same ends which are to increase the body of scientific knowledge, to improve the recipe and to change the people.

This whole thing called science can best be understood by using some of the latest thinking coming out of science itself, the idea of 'complex adaptive systems'. Parenthetically, such recursiveness - describing things in terms of themselves - is very much part of the way we are coming to understand such complexity. From this perspective, science is not some mechanical process - turn the handle and out pops science. Indeed, even the recipe part, the most likely candidate for being a mechanism, is not really mechanical, since it is constantly being changed on the fly. Instead science is a complex, interacting, adapting, evolving system made up of living things and their ideas. What sets it apart from other such systems, such as art, religion or politics, is that the idea of belief is deliberately and persistently winnowed out of science, despite the persistent human tendency to keep putting it back in. Each of those other human enterprises has at its base a kernel of some fundamental and fundamentally unprovable, and hence illogical belief, whether it be belief in a god, an aesthetic or a manifesto, on which it then constructs the logic of itself. Even mathematics has this character, and is thus not scientific.

Science works both because of and despite its human part.

Thus our first problem with science is that it is too simply subtle - not simply too subtle, and that lots of people, including many scientists, actually misunderstand it. That this is so is no great shakes, since the science algorithm is supremely adaptive and robust, and can cope with lots, even many people misunderstanding it. The body of scientific knowledge is also supremely adaptive in that it can cope with and self-correct lots of mistakes and errors, which really amounts to coping with the frailty, the humanity, of people.

The second thing that science is not is relative. Now it might have seemed from the previous discussion that if science is not the truth, then it might not offer absolutes, and hence the best it might be would be some sort of relative description of the world, some sort of contingent or culturally-bound knowledge. Thus at best all it might be is one view of the world among many, and competing with the many for its place in the sun. The 'science is relative' view says that science is but one way of knowing the world and that it is not superior to or more valuable than other ways of knowledge. This is a sad misreading of science, because it confuses, sometimes mischievously, a part of science, its body of knowledge, with the whole - the knowledge, the algorithm and the people.

The body of scientific knowledge is not, and cannot be, 'the truth', since it is always subject to revision. It is at best, our best guess at the truth, whatever that is. The knowledge is not absolute, but that is not the same as saying that science itself is relative - that it is no more than any other way of knowledge - and that anything goes. In fact, science is quite muscular and assertive in saying that some ideas about the world are just rubbish, and it says this independently of the sincerity or saintliness, or even the nuttiness, of those who cleave to these ideas.

No, what science is most like is a modern airport. It is always under construction, destined never to be completed, a place of great confusion and chaos, and yet a place where things get done, where progress is made every day. In this analogy, knowledge is constructed rather than discovered as a fully human activity, but constructed through the application of the most powerful recipe we know. Part of the power of the recipe resides in the way its constructive, creative part is always offset by its destructive, critical part. We can see the power in the edifice it has created, an edifice that can withstand the essentially trivial destructive forces from outside science as well as the formidable destructive forces from within. It is a feature of science that the external forces wax and wane, but the internal ones never abate. All of science, the whole edifice, is a work in draft, subject to revision and reconsideration.

The idea that science might be constructed rather than discovered is quite alarming to some scientists. But this need not be so. Their alarm is built on a misunderstanding, and a misplaced fear, that the deconstructionists of the humanities could have a field day deconstructing a constructed science. The idea that science may be threatened by such post-modernist nonsense has been beautifully put to rest by Alan Sokal in his delightful spoofs. Science's internal destructive forces, so essential for its proper working, are a far more potent source of criticism and hence renewal than any external fad can hope to be.

If this is what science is from the inside, as it were, then how does it look to those on the outside? How does science look to poets, priests and politicians? Or, to put it less personally, to the arts, religion and the body politic?

Poets have long been troubled by science. Since at least the time of Keats, they have accused science of robbing the world of beauty. Newton, thought Keats, had unwoven the rainbow with his optics and the world had lost a sense of wonder thereby. But this misconstrues the nature of science, as Richard Dawkins argues in his fine new book which takes 'unweaving the rainbow' as both its title and theme. It is true that science has shown us that we live in a purposeless cosmos, and that life itself has no grander purpose than to continue to exist. But that is not the same as saying that there is no beauty in the scientific view of the world. Indeed our contemplation of the beauty of a flower, say, is surely the more profound if we also understand something of the intricacies of its development, the history of its evolution, in short its remarkable place in the scheme of things. It is not going too far to say that much appreciation of beauty, of aesthetics, in poetry or any of the arts, is quite superficial and uncomprehending of the deeper aesthetics that a scientific understanding can give. We can be even more critical and remark that aesthetics is, after all, a construct, an artefact of human society, and as such can itself be the proper subject of scientific understanding.

Priests, whether from mainstream religions or from flaky cults, are at least united in their distrust of science. Since Galileo's time, science and religion have fought over the right to interpret the nature of the world. And since that time, religion has been on the back foot, as science has steadily encroached on its territory. Galileo's heresy was only the first. It pushed man from his privileged position at the geographic centre of God's universe. We now know that we inhabit a tiny planet, orbiting an average star in an unremarkable galaxy, adrift in a vast impersonal cosmos.

The science of Darwin showed that man was not unique among God's creatures, but, like all other living things, an accident of fate, evolved by chance through natural selection, a process that Darwin described in a letter to the botanist Joseph Hooker as one of 'the clumsy, wasteful, blundering, low and horribly cruel works of nature'.

Not content with showing that there is no god, no heaven, that man has no soul, science now takes the fight right up to religion's gates by seeing it, one of the more interesting social behaviours exhibited by human beings, as an object worthy of its attention. Religious behaviour itself is now the subject of analysis by evolutionary biologists keen to understand the survival value it seems to bestow on societies and individuals. Science was once in religion's dock, religion is now under science's microscope.

Politicians too have their reasons to fear science. Those of the left find the ideas of evolutionary biology confronting. They find unsettling science's conclusions that there are strongly inherited components to many ugly human behaviours, such as aggression, promiscuity, xenophobia, infanticide, and male dominance, let alone traits like intelligence and happiness. They would like to ignore the inconvenient fact that we are apes with a repertoire of behaviours that have been shaped by evolutionary forces. Such science is just not helpful to those on the left who wish to improve the world through social engineering - education, social welfare and the like. Politicians of the right fare little better at the hand of science, for they find that it has obliterated the core conservative belief in a proper order of things. With no god to provide order or meaning, no purpose in the universe, no reason for living things beyond their own existence, and no essential distinction between man and other living things, conservatives are left with little to conserve.

Beyond the disquiet, or even fear, that science raises in the breast of poets, priests and politicians, we can also see another sign of the steady encroach of science in the various human enterprises that appropriate its name. These put on the mantle of science to cover the fact that, at base, they are founded in belief. Indeed, I might even suggest in passing that one should be wary of any activity that needs to add the word 'science' to its name. Think of creation science, Christian Science, economic science or even sad cults like Heaven's Gate, the science-obsessed members of which, you will remember, 'shed their containers' so they could join a spacecraft hiding in the tail of Hale-Bopp comet. All such cults, religions and doctrines have a bedrock of belief, whether in astounding processes such as the transubstantiation of matter or the special creation of man, arbitrary phenomena such as the existence of a soul or a deity, or peculiar ideas such as 'the rational man' or 'the power of prayer'.

These enterprises are all sad parodies of science. They assume science's name and some of the trappings, but they really just do not get science's central, subversive message: science is that human activity that allows us to shed belief.

What poets, priests and politicians have really found is that science is subversive to belief, it undermines it at every turn.The arts, religion and the body politic each in their own way seek to control the way we understand the world. With varying degrees of subtlety and success, they each say: accept this belief, follow this logic, cleave to this world-view. Science subverts this by showing that there is another way of understanding the world that does not start with the assumption of belief. Instead, it draws its power from what a mathematician would call its 'piece-wise continuousness' - science is one continuous fabric, with holes and rips, frays and puckers to be sure, but a fabric where threads connect each part to every other. Thus each imperfect explanation of each bit of the world draws strength from all the other imperfect explanations of all the other bits. Neither the arts, nor religion, nor the body politic, even with their powerful logics and compelling beliefs encompassing their bits of the world, can compete with this magisterial thing called science.