The Human Touch: Our part in the creation of the universe, by Michael Frayn FABER £20 £18 (P&P FREE) 08700 798 897

What we bring to the party

It is unfair of sceptics to dismiss psychology as mere alchemy. Whatever the deficiencies of Freud and his successors, the alchemical stage in our understanding of human beings was always that catalogue of speculation and dogma known as literature. Even today, a novelist can still round off a chapter with a grand pronouncement about life or men and women without fear that the reader might demand evidence or argument to support his claim. Such authorly "insights" are the currants that make the cake, for we like to think that a great work of literature is not just inspiring, but also contains eternal truths. We do not wonder about the writer's sample size or his controlled conditions, for to doubt his intuitive grasp of the world and his authentic vision would be philistine. However, this has not prevented scientists from trespassing on the novelist's territory at will; seeking to expose the conditions for happiness and the recipe for love itself. Were proper account to be taken of such research, then poets and novelists would be reduced to the status of upmarket entertainers. Their vaunted insights would at best provide illustrations with which to jazz up the papers in a scientific journal.

It is about time that a writer fought back, and few could hope to do so in as eloquent and well-informed a fashion as Michael Frayn. His latest book is the culmination of a lifetime's engagement with the central enigma of our existence: we are a speck of dust on a speck of dust in the cosmic scale, yet the world has no form before human beings impose a structure upon it. It should be said at the outset that any panic about our sheer tininess is misplaced, for it betrays an irrational fascination with size - as if fat people are inherently more significant than anorexics, or the sterile gas giant Jupiter should eclipse the planet Earth in anything other than girth. As for the brevity of our lives in the vastness of time, Bertrand Russell dispatched the problem when he pointed out that if nothing we do today will matter in 1,000 years, then nothing that will happen in 1,000 years matters today - including the fact that nothing we do today will matter at that point.

To Frayn, what we do now matters very much indeed, because "the world has no form or substance without you and me to provide them." We know that had there been no human beings, there would not have been any ecstasies or depressions. Whether there would have been any "beautiful" sunsets as opposed to just sunsets is a more difficult question. But according to Frayn, we should not think it obvious that there were any sunsets at all either. The means by which we describe and explain the setting of the sun are as peculiarly and inescapably human as the reverie it evokes.

With the help, he confesses, of his popular science library, he shows that there is too much artifice in science and philosophy to demote great literature. However, anyone hoping for a tidy explanation of the mysteries Frayn alludes to in his plays and books is in for a shock and a very tough ride. This is no gentle introduction to the issues. We are told that no prior philosophical training is required, but one will need more than a good dictionary. For example, not every educated reader will know what is meant by "phenomenalism". However, this is not a weakness. Many readers will be glad to cut to the chase, and the others can rest assured that their effort will be repaid.

The idea of an observer, he argues, is essential to the understanding of virtually all our scientific notions - and not just quantum mechanics. As he anticipates, his insistence might be dismissed as anthropomorphism. Human observations are a subset of the effects that things have on one another, so that whilst I might observe the weight of a boulder by trying to lift it, the soil beneath "observes" the same quality by being compressed. An object that had no effect on anything else could not properly be said to exist, but there is no need for all effects to be brought to bear on human beings in particular. Neither is one compelled to make a distinction between the "primary" qualities of the boulder - its weight and shape - and its "secondary" qualities (such as texture and colour) that seem to require a person to experience them. The boulder's weight is thought more "real" than its colour only because the soil beneath it is far longer lived than any observer's retina. Clearly, we cannot base our account of the physical world on a prejudice against short periods of time. However, it seems even more perverse to cultivate a prejudice in favour of them.

If a tree falls in a forest and no one hears it, then does it make a sound? It's easy to say no, but then did it make a sight if no one saw it, an impact if no one felt it, and so on? If you answer no to all these questions, then soon you will have denied that the tree actually fell, since its falling consists in making a sight, a sound, an impact. If you have got as far as accepting that a tree fell, then you have already accepted that it made a sound, observers or no observers. To the extent that we construct the world around us, we do not seem to have much choice in how we do so, which leaves us rather in the situation we once naively assumed - enveloped by an absolute, objective and unchangeable reality. Our immutable nature as human beings is part of the world too, after all.

In the final analysis, even scientists might not seem to have a particularly secure handle on the physical world. Yet we still seem to be able to do quite a lot - navigating the streets, sending rockets to the moon and curing diseases - so either our handle is rather firmer than we think, or else not having one does not matter. As the author himself concedes, "Soon I shall close my eyes not temporarily and experimentally, but permanently and in earnest... and we both know that the universe will go on exactly as before."