The title refers, of course, to Stephen Hawking’s well-known (~988) book, A Brief History of Time. There Hawking concludes that we are close to the moment when we shall read the mind of God, close to the end of science. Once the ‘complete theory’ of the universe is discovered, the only remaining question would be ‘why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason…’ Then we would know the mind of God.
Hawking’s conclusion reflects the traditional view of what should be the ultimate goal of physics. Already, three centuries ago, W. Leibniz, one of the founders of modern science, wrote that if we knew the ‘full causes’ and ‘entire’ effect, our knowledge would become comparable with God’s knowledge of the world He created. The idea ofa final theory – ‘a theory of everything’ – is quite alive today, as testified by two recent books, Dreams of a Final Theory by Steven Weinberg and The God Particle by Leon Lederman.
It is indeed a grandiose program. Again, to quote Leibniz, ‘In the least of substances, eyes as piercing as those of God could read the whole course of the universe’. There would be no distinction between past present and future; we would share the certitude of God.
No doubt the claim to certainty has been at the basis of the conviction that science expresses rationality at the highest level and that progress in social and political sciences should be linked to the application of scientific laws to society; however there is today a growing doubt about the ideology of science. In his book The Closing of the American Mind, (the late) Allan Bloom wrote: ‘The idea of culture was established in an attempt to find the dignity of man within the context of modern science. That science was materialistic, hence reductionist and deterministic’.
None of these qualifications applies to the present situation in science, but before coming to this point let us put the idea of certainty into its historical perspective. In his most interesting 1990 book Cosmopolis, Stephen Toulmin points out the tragedy of the ~7th Century, the religious wars, the political in stability. It was in the midst of this difficult situation that Rene’ Descartes formulated his quest for certainty, a certainty that all humans, independently of their religion, could share. A quest for certainty in philosophy is based in his famous ‘cogito,’ as well as in science based on mathematical proofs. Descartes programme proved to be immensely successful. It influenced Leibniz’s concept of ‘laws of nature’. It found its concrete realisation in Newton’s work, which has been the model for physics for more than three centuries…
For Einstein, also, science was a way to go beyond the turmoil of everyday existence. He compared scientific activity to the ‘longing that irresistibly pulls the town-dweller away from his noisy, cramped quarters and toward the silent, high mountains’. For him, also, certainty was the supreme ideal of science. Everyone knows his saying ‘God does not play dice’.
The idea of certainty, when seen in its historical perspective, is associated with a denial of time and novelty and therefore leads to a pessimistic outlook, which ultimately leads to alienation. It is often stated that science is neutral; this seems to me only partly true. How can science be neutral when it deals with our very position in nature? This feeling of alienation has not only been expressed by critics of science, philosophers and theologians, but we find it also in Weinberg’s oft-quoted remark, ‘The more the universe seems comprehensible, the more it seems pointless’.
Indeed, the ideal of certainty forces us to give up the notion of events and eliminates novelty and creativity, with out which our own lives would indeed be pointless. The denial of time makes us foreigners in the world we try to describe. The logical consequence is dualism. According to Descartes we have on one side matter viewed as pure extension following deterministic laws, on the other side intellectual activity radically separated from matter.
In The Emperor’s New Mind (1989), Roger Penrose wrote, ‘It is our present lack of understanding of the fundamental laws of physics that prevents us from coming to grips with the concept of “mind” in physical or logical terms’. I think that Penrose is right. We need a reappraisal of what we mean by the ‘fundamental laws of physics’.
This reappraisal is already starting. While president of the International Union of Theoretical and Applied Mechanics, Sir John Lighthill wrote in 1986 in the Proceedings of the Royal Society: ‘We are all deeply conscious today that the enthusiasm of our forebears for the marvellous achievement of Newtonian mechanics led them to make generalisations in this area of predictability that … we now recognise are false. We collectively want to apologise … for spreading ideas about determinism that after 1960 were to be proven incorrect.’
This is a quite unusual confession. Here, certainty, which for three centuries appeared as the key symbol of scientific intelligibility, is put into question. Lighthill refers to what is known as the theory of ‘chaos’, started by Henri Poincare’ at the end of the 19th Century. There can be no possibility in the framework of this short article to explain chaos. Innumerable books and articles are readily available. Chaos has many aspects, some of which we are only beginning to understand. However, I want to make a remark that arises from recent work by my groups in Austin and Brussels.
That is that chaos changes the formulation of the laws of physics. Instead of expressing certitudes, they express possibilities. At its start, the universe was like a new born child who can become a lawyer, an astronaut or an architect – but not all at the same time. As W. Thirring has written: ‘Our formulation of the laws of nature cannot contradict experience, otherwise they should be modified, but they will be far from determining everything. As the universe evolves, the circumstances create new laws’.
Giving up the ideal of certainty may appear to be a defeat of human reason. I don’t believe so. Once we replace the deterministic description with a description involving probability, we can introduce the arrow of time into our basic equations. We begin, then, to be able to describe an evolutionary universe in agreement with our present picture in which evolution plays an essential role on all levels of description, from cosmology to human history…
In his 1991 book The Passion of the Western Mind, Richard Tarnas wrote that ‘the deepest passion of the western world is to reunite with the ground of its being’. We need a science whose progress marks the solidarity of men with the world it describes.
The future is uncertain; this is true for the nature we describe and this is true on the level of our own existence. But this uncertainty is at the very heart of human creativity. Time becomes ‘construction’ and creativity a way to participate in this construction.