Those who love literature rather take for granted the idea of a literary tradition. In part, it is a temporal map, a means of negotiating the centuries and the connections between writers. It helps to know that Shakespeare preceded Keats who preceded Wilfred Owen because lines of influence might be traced. And in part, a tradition implies a hierarchy, a canon; most conventionally, it has Shakespeare dominant, like a lonely figurine on top of a wedding cake, and all the other writers arranged on descending tiers. In recent years, the canon has been attacked for being too male, too middle class, too Euro-centric; what remains untouched is the value of a canon itself: clearly, if it did not exist, it could not be challenged.

But above all, a literary tradition implies an active historical sense of the past, living in and shaping the present. And reciprocally, a work of literature produced now infinitesimally shifts our understanding of what has gone before. You cannot value a poet alone, TS Eliot argued in his famous essay, "Tradition and the Individual Talent", "you must set him, for contrast and comparison, among the dead." Eliot did not find it preposterous "that the past should be altered by the present as much as the present is directed by the past." We might discern the ghost of Auden in the lines of a poem by James Fenton, or hear echoes of Wordsworth in Seamus Heaney, or Donne in Craig Raine. Ideally, having read our contemporaries, we return to re-read the dead poets with a fresh understanding. In a living artistic tradition, the dead never quite lie down.

Can science and science writing, a vast and half forgotten accumulation over the centuries, offer us a parallel living tradition? If it can, how do we begin to describe it? The problems of choice are equalled only by those of criteria. Literature does not improve; it simply changes. Science, on the other hand, as an intricate, self-correcting thought system, advances and refines its understanding of the thousands of objects of its study. This is how it derives it power and status. Science prefers to forget much of its past - it is constitutionally bound to a form of selective amnesia.

Is accuracy, being on the right track, or some approximation of it, the most important criterion for selection? Or is style the final arbiter? The writings of Thomas Browne or Francis Bacon or Robert Burton contain many fine passages that we now know to be factually wrong - but we would surely not wish to exclude them. The tradition must keep a place for Aristotle and Galen because of the hold they had over people's minds for centuries. We have to beware of implying a Whig history of science, a history of the lonely road that leads to the present. We need to remember the various discarded toys of science - the humours, the four elements, phlogiston, the ether and, more recently, protoplasm. Modern chemistry was born out of the futile ambitions of alchemy. Scientists who hurl themselves down blind alleys perform a service - they save everyone a great deal of trouble. They may also refine techniques along the way, and offer points of resistance, intellectual cantilevers, to their contemporaries.

I say all this somewhat dutifully, because there actually is a special pleasure to be shared, when a scientist or science writer leads us towards the light of a powerful idea which in turn opens avenues of exploration and discovery leading far into the future, binding many different phenomena in many different fields of study. Some might call this truth. It has an aesthetic value that is not to be found in Galen's confident and muddled assertions about the nature of disease. For example, there is something of the luminous quality of great literature when the 29-year-old Charles Darwin, just two years back from his Beagle voyage and 21 years before he will publish The Origin of Species, confides to a pocket note-book the first hints of a simple, beautiful idea: "Origin of man now proved ... He who understands baboon would do more towards metaphysics than Locke."

Far better, perhaps, to set aside issues of truth and inaccuracy, criteria and definitions. We know what we like when we taste it. Until recently, the purely literary tradition was never obliged to set out its terms. The work came first, and then the talk about it. In a sense, I am merely making an appeal for a grand parlour game: what might a scientific literary tradition be? Which books are going on our shelves? To propose is to ask to be challenged; already, I suspect my own suggestions are too male, too middle class, too Eurocentric.

Here is the opening of an essay - strictly speaking, a letter - on immunology.

"It is whispered in Christian Europe that the English are mad and maniacs: mad because they give their children smallpox to prevent their getting it, and maniacs because they cheerfully communicate to their children a certain and terrible illness with the object of preventing an uncertain one. The English on their side say: 'The other Europeans are cowardly and unnatural: cowardly in that they are afraid of giving a little pain to their children, and unnatural because they expose them to death from smallpox some time in the future'. To judge who is right in this dispute, here is the history of this famous inoculation which is spoken of with such horror outside England."

This is Voltaire, writing in the late 1720s during an extended visit to England, presenting a rare instance of a French intellectual impressed by English ideas. Voltaire wrote beautifully in his Lettres philosophiques - translated as Letters on England - on religion, politics, and literature. He was delighted by the degree of political freedom he found here, by the powers of parliament, the absence of religious absolutism and divine right. He attended Newton's funeral and was amazed that a humble scientist was buried like a king in Westminster Abbey. Crucially, he placed himself between a scientist and an interested public and offered superb expositions of Newton's theories of optics and gravitation, which still stand today. If you want to know what was daring and original in what Newton said, read Voltaire. He communicates the excitement of a new idea, and sets the highest standards of lucidity.

Last year, my son William completed an undergraduate biology course at UCL. When he came to study genetics, he was advised to read no papers written before 1997. One can see the point of this advice. In recent years, estimates of the size of the human genome have shrunk by a factor of three, or even four. Such is the headlong nature of contemporary science. But if we understand science merely as a band of light moving through time, advancing on the darkness, and leaving ignorant darkness behind it, always at its best only in the incandescent present, we turn our backs on an epic tale of ingenuity propelled by curiosity.

Here is a man who has ground up some lenses with infinite care and arranged them in a novel way. He has taken some water from a lake and has been studying it scrupulously, with an open mind: "I found floating therein divers earthy particles and some green streaks , spirally wound serpent-wise and orderly arranged ... Other particles had but the beginning of the foresaid streak; but all consisted of very small green globules joined together; and there were very many small green globules as well ... These animacules had divers colours, some being whitish and transparent, others with green and very glittering little scales ... And the motion of most of these animacules in the water was so swift, and so various upwards, downwards and roundabout, that 'twas wonderful to see: and I judge that some of these little creatures were above a thousand times smaller than the smallest ones I have ever yet seen ..."

This is Anton van Leeuwenhoek writing from Holland to the Royal Society in 1674, giving the first account of spirogyra, among other organisms. He sent his observations to the Royal Society over a period of 50 years, and it was no accident that he should have sent his letters there. At that time, in a small space, within a triangle formed by London, Cambridge, and Oxford, and within a couple of generations, there existed nearly all the world's science. Newton, Locke, (I think we need to include certain philosophers - Hume most certainly) Willis, Hooke, Boyle, Wren, Flamsteed, Halley - an incredible concentration of talent, and the core of our library - its classical moment, if you like.

This year marks the thirtieth anniversary of the publication of Richard Dawkins' The Selfish Gene. There has never been a science book quite like it. Drawing on the work of a handful of scientists, it bound together genetics and Darwinian natural selection in a creative synthesis that amazed even those few who were already familiar with the concepts. It hastened a sea change in evolutionary theory, it affected profoundly the teaching of biology, it enticed an enthusiastic younger generation into the subject, and spawned a huge literature, and eventually a new discipline - memetics. At the same time, and this is the measure of its achievement, it addressed itself without condescension to the layman. It did so provocatively, and with style.

"Individuals are not stable things, they are fleeting. Chromosomes too are shuffled into oblivion, like hands of cards soon after they are dealt. But the cards themselves survive the shuffling. The cards are the genes. The genes are not destroyed by crossing over, they merely change partners and march on. Of course they march on. That is their business. They are the replicators and we are their survival machines. When we have served our purpose, we are cast aside. But genes are the denizens of geological time: genes are forever."

It is a lovely phrase, "shuffled into oblivion", and the analogy with cards - the hand being the information, the cards themselves the genes - is apt, economical and informative: true eloquence. In the years since then, Dawkins' work might be seen as one extended invitation addressed to us non-scientists to enjoy science, to indulge ourselves at a feast of human ingenuity. Just as we can sit around the kitchen table and discuss operas, movies or novels without being composers, directors or novelists, so we can engage with this subject, one more sublime achievement of accumulated creativity. We can make it "ours" just as we might the music of Bach or Bill Evans.

A literary tradition in science would certainly help us in that, and one important contribution to the development of the idea of a living past is John Carey's Faber Book of Science, a magisterial anthology, superbly annotated. In it there is a long extract from Thomas Huxley's famous lecture "On a Piece of Chalk", delivered to a packed hall of working men in Norwich in 1868. The lecture contains the seductive sentence, "A great chapter in the history of the world is written in the chalk ..."

Huxley leads us, of course to Darwin. My particular favourite is The Expression of the Emotions in Man and Animals, in which he makes the case for emotions as human universals, shared across cultures. He also makes an anti-racist argument for a common human nature. This is one of the first science books to make use of photographs - in this case, one of the Darwin babies bawling in a high chair. The edition by Paul Ekman is unsurpassed.

When we come to the present, our parlour game intensifies, for we are wallowing in riches. The Selfish Gene stood at the beginning of a golden age of science writing. With a fine sense of literary tradition, the physicist Steven Weinberg, in his book Dreams of a Final Theory, revisited Huxley's lecture on chalk in order to make the case for reductionism. Steven Pinker's application of Darwinian thought to Chomskyan linguistics in The Language Instinct is one of the finest celebrations of language I know. Among many other indispensable "classics", I would propose EO Wilson's The Diversity of Life on the ecological wonders of the Amazon rain forest, and on the teeming micro-organisms in a handful of soil; David Deutsch's masterly account of the Many Worlds theory in The Fabric of Reality; Jared Diamond's melding of history with biological thought in Guns, Germs and Steel; Antonio Damasio's hypnotic account of the neuroscience of the emotions in The Feeling of What Happens; Matt Ridley, unweaving the opposition of nature and nurture in Nature via Nurture; and recently, the philosopher Daniel Dennett, conscious of Hume as well as Dawkins, laying out for us the memetics of faith in Breaking the Spell

An important part of Richard Dawkins' writing and public speaking has been devoted to religion - he has refused to gloss over the innate contradictions between reason and faith. Few of us, I think, in the mid-1970s, when The Selfish Gene was published, would have thought we would be dedicating so much mental space to discussing religious faith in this new century. We thought that since it has nothing useful at all to say about cosmology, the age of the earth, the origin of species, the curing of disease or any other aspect of the physical world, it had retreated finally to where it belongs, to the privacy of individual conscience. We were wrong. A variety of sky-god worshippers with their numerous, mutually exclusive certainties (all of which we must "respect") appears to be occupying more and more of the space of public discourse. Increasingly, they seem to want to tell us how to live and think, or inflict upon us the strictures they choose to impose upon themselves. This is a passage taken from Carey's anthology, and in my ideal science library I would want it carved in some special place - perhaps over the door as you go in. Here is a man who has just been threatened with torture and indefinite imprisonment, unless he signs on the dotted line: "... having before my eyes and touching with my hands the Holy Gospels, swear that I have always believed, do believe, and with God's help will in the future believe all that is held, preached and taught by the Holy Catholic and Apostolic Church ... I must altogether abandon the false opinion that the sun is the centre of the world and immovable, and that the earth is not the centre of the world and moves and that I must not hold, defend or teach in any way whatsoever, verbally and in writing the said false doctrine ..."

Or, as Orwell would have it, two plus two equals five. In 1632 Galileo might just have whispered to himself as he signed, "but it still moves" - we will never know. But his confession reminds us that open-minded rational enquiry has always had its enemies. We can take nothing for granted, for totalitarian thinking, religious or political, will always be with us in some form or other. For this reason alone, we should nurture a living scientific literary tradition.

© Ian McEwan 2006. This is an expanded version of a talk given by Ian McEwan at the London School of Economics to mark the 30th anniversary of The Selfish Gene.

A science canon

Francis Bacon Advancement of Learning

Antonio Damasio The Feeling of What Happens

Charles Darwin The Expression of the Emotions in Man and Animals (ed Ekman)

Richard Dawkins The Selfish Gene

David Deutsch The Fabric of Reality

Jared Diamond Guns, Germs and Steel

Galileo Galilei Dialogues Concerning Two New Sciences

Brian Green The Elegant Universe

David Hume A Treatise of Human Nature

Ernst Mayr This Is Biology

Steven Pinker The Language Instinct

Matt Ridley Nature Via Nurture

Voltaire Letters on England

Steven Weinberg Dreams of a Final Theory

EO Wilson The Diversity of Life