A Return to Reason and Sanity

The rational truth of God, the immortality of the soul, and the natural law as the foundation of ethics and morality presented as the antidote to the irrationality of the "new atheism", moral relativism, and cultural subjectivsim of our age. Your civil, courteous, and thoughtful comments and ideas are welcome. This blog is a forum to discuss ideas not personalities. Thank you.







Tuesday, June 28, 2011

God, Aquinas, and Dawkins: The Three Ages of Science

The Three Ages of Science.

The historical development of science can be divided into three stages in two different ways, within science itself and also against the background of the beliefs of society.

Within science, we can distinguish three distinct views of the world, as an organism, as a mechanism and as a mathematical formalism. The ancient Greeks, anxious to preserve human values, viewed the world as an organism, but this was a failure. In the Renaissance, when science came to maturity with Newton, the world became a mechanism, following precise mathematical equations. If we know the initial conditions, these enable us to calculate all subsequent motions, and the results are in precise agreement with our measurements. Finally, in the present century, mechanistic physics proved inadequate, and now for much of our work, we rely mainly on the mathematical equations, although physical understanding is still essential.

The relation between science and the society in which it lives also passes through three stages. In the first stage, most of the beliefs about the material world prevented or hindered the growth of science. Eventually science struggled into existence in the High Middle Ages when the Christian beliefs about the world provided the necessary conditions for its birth. It came to maturity in the Renaissance, and at that time most of the pioneer scientists were believing Christians who saw their work as showing forth the glory of God. At this point science became an autonomous self-sustaining enterprise that develops in accord with its own internal criteria, although it was still within a broadly Christian society. It needed the material support of society, and the relations between science and society were not always smooth. There have been from the beginning tensions between the scientists on the one hand and the theologians, the Church and the State authorities on the other, and among scientists between Christians and secularists. These can be a stimulating and healthy tensions, but they often degenerate into mutual incomprehension and hostility. Examples abound: Luther and Melanchthon attacked the Copernican theory, and Galileo was punished for his views. Nowadays the tension continues: many theologians are apprehensive of science, scientists like Hawking and Dawkins attack and pour scorn on theology, and there are continual battles with Government agencies to obtain sufficient support for scientific research.

In the present century we have moved into the third stage, when science more and more frequently finds itself in a society that is no longer broadly Christian, but indifferent or anti-Christian, either in its ideological roots or through the authority of the State. Science has spread rapidly over the world to non-Christian societies, as people become aware of its technological applications. But there is an important distinction; technology is easily exported and readily welcomed, but science is extremely difficult to export. Schools and universities all over the world teach science, but in most cases this has proved rather difficult, and it is not at all easy to establish really fruitful research programmes. Twice in Europe science has come under totalitarian regimes that have treated science as a slave or as a god, in Nazi Germany and in Soviet Russia. In both cases the effect on science has been disastrous, and science withered. Can science survive in a post-Christian society?

References

J. Barbour, Absolute or Relative Motion: 1. The Discovery of Dynamics. Cambridge, 1989.
E.A. Burtt, The Metaphysical Foundations of Modern Physical Science . Routledge and Kegan Paul, 1932
S. Chandrasekhar, Truth and Beauty. Chicago, 1990.
R. Feynman, Surely You're Joking, Mr. Feynman?
A.R. Hall, The Scientific Revolution 1500-1800. Longmans, 1954.
G. Holton, Thematic Origins of Scientific Thought: Kepler to Einstein. Harvard, 1973.
A. Koestler, The Watershed: A Biography of Johannes Kepler. Doubleday, 1959.
D.C. Lindberg, The Beginnings of Western Science. Chicago, 1992.
W.R. Shea, Galileo's Intellectual Revolution. Science History Publications, 1977.
C.S. Singleton (Ed), Art, Science and History in the Renaissance. Johns Hopkins Press, Baltimore, 1967.
R.S. Westfall, Never at Rest: A Biography of Isaac Newton. Cambridge, 1980.

God, Aquinas, and Dawkins: The Christian Origin of Science

The Christian Origin of Science

During the Middle Ages, the thought of Europe was moulded and dominated by Christian theology and philosophy. It is therefore interesting to see how the beliefs that we have seen are necessary for science are related to Christian beliefs about the world. There is indeed a close relation between them, so Christian theology prepared the way for science by teaching that particular attitude to the world that provides the basis of science.

We can see this by recalling the beliefs already listed. The Christian believes that the world is good because God made it so: "And God saw all that He had made, and indeed it was very good" (Genesis 1.31). Matter was further ennobled by the Incarnation: "The Word was made flesh and he lived among us" (John 1.14). The world is rational and orderly because it is made and kept in being by a rational God. It is contingent because it depends on the divine fiat: God could have chosen to make the world in a different way. There is here a delicate balance between the freedom and the rationality of God: tip the balance one way or the other and you have a belief in a chaotic or a necessary world, both inimical to the growth of science. Finally the Christian believes that the world can be apprehended by the human mind because God commanded man to subdue the earth, and he does not command the impossible: "Be fruitful, multiply, fill the earth and conquer it. Be masters of the fish of the sea, the birds of heaven and all living animals on the earth" (Genesis 1.28). Thus the Christian mind is steeped through and through with the beliefs about the material world that are necessary for the development of science.

The Christian also has the strongest motivation to study the world. Christ himself reiterates the divine command to subdue the earth when by the parable of the talents he urges us to make full use of all our faculties and powers. Furthermore, as soon as it becomes clear that scientific knowledge can be applied to grow more food and improve his medical care, to provide better clothes and housing, it becomes a special obligation on man to do this in view of the injunction to feed the hungry, to give drink to the thirsty and to clothe the naked.

The remaining condition for the development of science, the belief that knowledge must be freely shared, is enjoined by the Book of Wisdom: "What I have learned without self-interest, I pass on without reserve; I do not intend to hide her riches. For she is an inexhaustible treasure to men, and those who acquire it win God's friendship" (Wisdom 7.13-14). The Book of Wisdom also contains the declaration that the Creator ordered everything in measure, number and weight (11.20), the most frequently quoted Biblical phrase in medieval times.

We thus find that during the critical centuries before the birth of science the collective mind of Europe was moulded by a system of beliefs that included just those special elements that are necessary for the birth and growth of science. There is thus a living organic continuity between the Christian revelation and modern science. Christianity provided just those beliefs about the material world that are essential for science, and the moral climate that encouraged its growth.

It might however be said that the medieval origin of science is just a historical coincidence: how can we know that there is a real causal influence operating? This can indeed be found if we examine the work of some of the philosophers of the Middle Ages.

At that time the prevailing ideas of the nature of the world were derived from the Greek philosopher Aristotle. He believed in the eternity of the world, in a cyclic universe and in a world of purpose even in material things. He also believed that celestial matter, the world of the stars and the planets, is incorruptible, unlike terrestrial matter that can undergo change. These beliefs in effect prevented the development of science for two thousand years, This stranglehold had to be broken before science could develop into its modern form.
So great was the prestige of Aristotle that the philosophers of the medieval schools taught by commenting on his texts. Some of Aristotle's teaching, however, was inconsistent with the Christian faith, and the philosophers did not hesitate to differ from Aristotle when it seemed necessary. In 1215 the Fourth Lateran Council decreed that all creation, spiritual and material, took place out of nothing and in time. This is directly contrary to Aristotle's belief in the eternity of the world accepted as a self-evident truth. There was intense discussion on a variety of topics, notably concerning the creation of the world and the motion of bodies. In 1277 the bishop of Paris, Etienne Tempier, found it necessary to condemn 219 philosophical propositions as contrary to the Christian belief. His main purpose was to defend God's absolute power against any attempt by the Aristotelian philosophers to set limits to it. Several of the condemned propositions set limits to God's power, saying for instance that He cannot make more than one world or to move the world so as to produce a vacuum. Tempier thus reasserted the belief that God can freely create any world, just as He chooses. This was a turning point in the history of thought, as it liberated philosophers from bondage to Aristotle and channelled philosophical speculations about motion in a direction that led eventually to the destruction of Aristotelian physics, thus opening the way to modern science.

The theology of divine omnipotence had important consequences for the development of science as a result of Aquinas' distinction between God's absolute and ordained powers. God always has absolute power over all things, but he endows the natural world with specific natures, according to His plan for creation. These normally determine the behaviour of natural phenomena. It thus becomes a reasonable activity to try to find out about the world. Normally, by virtue of God's ordained power, the natural world strictly follows God's laws, and yet this does not prevent God from doing whatever he chooses by virtue of his absolute power. This reinforces the stability of nature as a sign of God's faithfulness so frequently expressed in the Old Testament (Jer 31:35-36; 33:25-26), while leaving open the possibility of miracles.

One of the medieval philosophers, Jean Buridan, was particularly interested in the nature of motion. This is the most fundamental problem of physics, and so if science is to begin it must begin here. In full consistency with his belief in creation, he wrote that 'God, when He created the world, moved each of the celestial orbs as he pleased, and in moving them He impressed upon them impetuses which moved them without Him having to move them any more except by the method of general influence whereby He concurs as co-agent in all things which take place'.

This shows a clear break with Aristotle, who required the continuing action of the mover throughout the motion. What Buridan called impetus was later refined into the concept of momentum, and the idea in the above passage became Newton's first law of motion. Buridan's works were widely published and his ideas became known throughout Europe, and in particular to Leonardo da Vinci and hence to the scientists of Renaissance times.

The Christian belief in the creation of the world by God also undermined Aristotle's sharp distinction between celestial and terrestrial matter. Since they are both created, why should they be different? Indeed, Buridan illustrated his concept of impetus with reference to the long jump; thus implicitly presupposing that celestial and terrestrial motions are similar. This made it possible for Newton to see that the same force that pulls an apple to the ground also keeps the moon in its orbit.

A vital component in the rise of science is the belief in the order of the world, that is the idea that every event is the precise result of preceding events. This implies that whatever measurements we make should correspond exactly, that is within the uncertainties of measurement, with our theories. A corollary is that if we want to test out theories we should make the most accurate measurements we can. This insistence on precision is essential for the progress of science, and it was made possible by the strong belief in the order of nature. It led Whitehead to say, in his Lowell lectures in 1925 on Science and the Modern World that 'the Middle Ages formed one long training of the intellect of Western Europe in the sense of order.' This by itself is not enough,and he went on:

I do not think that I have even yet brought out the greatest contribution of medievalism to the formation of the scientific movement. I mean the inexpungable belief that every detailed occurrence can be correlated with its antecedents in a perfectly definite manner, exemplifying general principles. Without this belief the incredible labours of scientists would be without hope. It is this instinctive conviction, vividly poised before the imagination, which is the motive power of research: -- that there is a secret, a secret which can be unveiled.
He went on to ask how was this conviction so vividly implanted on the European mind, and concluded: 'My explanation is that the faith in the possibility of science, generated antecedently to the development of modern scientific theory, is an unconscious derivative from medieval theology.'

One might indeed query whether unconscious is the right word, for many of the medievals explicitly saw their work as showing forth the works of the Creator. Furthermore, explicitly Christian beliefs played a decisive part in making modern science possible. Thus the debilitating belief in a cyclic universe was decisively broken by the Christian belief in the uniqueness of the Incarnation. Henceforth history was no longer an infinite series of dreary cycles, but a linear story with a beginning and an end.

The transition from Greek to modern physics has been graphically described by Pierre Duhem: 'The demolition of Aristotelian physics was not a sudden collapse; the construction of modern physics did not take place on a terrain where nothing was left standing. From one to the other the passage takes place by a long sequence of partial transformations of which each pretended to retouch or enlarge some piece of the edifice without changing anything of the ensemble. But when all these modifications of detail had been made, the human mind perceived, as it sized up with a single look the result of all that long work, that nothing remained of that ancient palace and that a new palace rose in its place. Those who in the sixteenth century took stock of this substitution of one science for another were seized by a strange illusion. They imagined that this substitution was sudden and that it was their work. They proclaimed that Peripatetic physics had just collapsed under their blows and that on the ruins of that physics they had built, as if by magic, the clear abode of truth. About the sincere illusion of arrogantly wilful error of these men, the men of subsequent centuries were either the unsuspecting victims or sheer accomplices. The physicists of the sixteenth century were celebrated as creators to whom the world owed the renaissance of science. They were very often but continuers and sometimes plagiarisers.'

The Work of Pierre Duhem

These Christian roots of modern science are not generally known. The man primarily responsible for uncovering the evidence for the Christian origin of science was the French physicist Pierre Duhem. He was a theoretical physicist working mainly in the field of thermodynamics, but had always been interested in the history of physics. He was asked to write a series of articles on the history of mechanics, and easily wrote the first one on the ideas of the ancient Greeks. Like most historians of science, he expected to pass rapidly over the Middle Ages to the giants of the Renaissance. But he was a careful man, not content to rely on secondhand sources. He found obscure references to earlier work, and following them up, primarily in the archives in Paris, he discovered the work of Buridan and his pupil Orseme, and of many other medievals who contributed to the origin of science.

Duhem wrote two volumes on the history of mechanics, three on Leonardo da Vinci, and then began a monumental account of the history of science in several volumes, the Systeme du Monde. The first volume, devoted to the Greeks, was published in 1913, and was highly praised by George Sarton, the founder and editor of the journal Isis, who said that he looked forward eagerly to the second volume. When however he read the second volume, he realised what Duhem had found was highly uncongenial to his secularist beliefs. Duhem left him in no doubt whatever. Writing on the doctrine of the Great Year, the belief that history continually repeats itself, he said: 'To the construction of that system all disciples of Hellenic philosophy -- Peripatetics, Stoics, Neo-Platonists -- contributed; to that system Abu Masar offered the homage of the Arabs; the most illustrious rabbis, from Philo of Alexandria to Maimonides, have accepted it. To condenm it and to throw it overboard as a monstrous superstition, Christianity had to come.'

Sarton did not try to refute Duhem; that would have been impossible. Instead he used the one remaining weapon, that of silence. None of the following volumes was reviewed in Isis, and the name of Duhem was thereafter hardly ever mentioned. In Sarton's own vast volumes on the history of science Duhem receives but a few mentions, whereas quite minor figures receive extensive discussion.

Tragically, Duhem died in 1916 when only five volumes of his Systeme du Monde, had been published. Duhem left the text of the remaining five volumes in MSS, and the publisher was bound by the terms of the contract to publish them in successive years. The secularist establishment however was bitterly opposed to their publication, and succeeded in preventing this for forty years. Only the death of his most determined opponent, and the threat of legal action, finally forced the publishers to act.

It is not surprising that secularists should be so determined to prevent the publication of books of massive scholarship that completely undermine their view of the development of science, and show that science as we know it is built on Christian foundations. What is surprising is that Christians have been so slow to recognise and to publish his work. Even today, after many decades of scholarly work on medieval science, the name of Duhem is hardly known outside specialist circles. It deserves to be familiar to all Christians, particularly those concerned with the education of the young, who are still taught that there is a fundamental opposition between science and the Christian faith.

Science in Eastern Christendom

This explanation of the rise of science in Western Europe during the High Middle Ages as due to the beliefs concerning the material world inherent in Christian theology raises the question why it happened in Western Europe and not in Eastern Europe, where Christianity also flourishes. One might indeed have expected science to arise first in the east, because it was the heir to the wisdom of ancient Greece, preserved and to some extent developed by Arab scholars. Thus from the eighth to the fourteenth centuries mathematics, astronomy, optics, physics and medicine were far more developed in Islamic countries than in Western Europe. In one vital area, for example, Arabic astronomers had so improved the Ptolemaic system that it was mathematically equivalent to the Copernican system, although it was still geocentric. And yet the lead was lost in one area after another as the West surged ahead and Arabic science decayed. This learning came to the West not via Eastern Christendom, but mainly through translations from the Arabic made in Spain. The Byzantine scientific tradition lacked originality, being content with the achievements of the Greeks and the Romans. They were thus unable to develop technology and to apply their theoretical knowledge for practical purposes.

Could the explanation of the difference between the vitality of science in the West and its virtual absence in the East be due to a difference between Eastern and Western theologies, or are there other explanations, perhaps in terms of sociological factors, which themselves may or may not have their origin in theology?

The theological beliefs of Eastern and Western Christendom are essentially the same, but there are important differences at the conceptual and practical levels. These differences are difficult to describe, because there are many counter-examples to any general statement that can be made. Thus both attach high value to reason and to prayer, but the emphasis is different. In the West, scholarly work is itself considered to be a form of prayer. Orders of friars, such as the Dominicans, were founded to preach, and to teach in schools and in universities, and their times of prayer are regulated to allow time for study. Dominicans such as Thomas Aquinas taught in the universities and used reason to find out what they could about God, thus developing scholastic theology. In the monasteries of the east, the monks spend long hours in prayer, but as a result they have less time for study and for writing.

Of great importance for the origin of science is the concept of time. Before the advent of science our activities followed biological time, governed by the natural processes of night and day, the phases of the moon and the progression of the seasons. In contrast, scientific time is a regular sequence, and to each instant there corresponds a number, measurable to high accuracy. Monasteries need to have a way of marking the time to regulate the hours of prayer and work and initially they followed biological time, supplemented by sand and water clocks. In the Western monasteries, clocks of high sophistication were developed as early as the twelfth century, whereas clocks, imported from the West, were not used on Mount Athos until the eighteenth century. Even now, the east has a more relaxed sense of time.

The use of biological time is associated with primitive technology, whereas more developed technology comes with scientific time. Thus the larger western monasteries made many technological advances for domestic and industrial purposes, such as water mills and saws. This is of crucial importance for the development of science.

There are also several sociological reasons why science arose in the west and not in the east. It is essential for creative intellectual work that there are places where it can be carried on without external interference, so that the people there are free to think what they like and to follow wherever their reason leads them. Such opportunities are provided by universities, and many were founded in the West from the twelfth century onwards. The crucial steps that led to the birth of modern science took place in the university of Paris.
In the east, there was a spectacular intellectual and artistic revival in the ninth century after the end of the iconoclastic controversy, and the university of Constantinople attracted many distinguished scholars. There was, however, little interest in science or technology.

Byzantine society was rigidly authoritarian, with Church and State closely linked. The Emperor was considered the vicegerent of God, and as ruler of both church and state his word was law. There was a highly centralised state organisation with a well-developed civil service, so that practically all activities were controlled by the Emperor. Trade and commerce were rigidly controlled, not to serve the interests of the merchants but to subordinate economic life to the interests of the state. There were indeed schools, but they did not encourage independent discussion, and the static conception of life was not conducive to the development of science. In the west, on the other hand, the universities were centres of intellectual discussions, where novel views were expounded and discussed.

People speak and discuss freely when they are personally secure, when they know that they can say what they like without danger of any kind. This security can be provided by belonging to an organisation, such as a university, which encourages free discussions, or by a society that respects the right of private property. In the west this is legally established, whereas in the east property was held subject to the will of the ruler, and may at any time be revoked. If one lives in perpetual fear that the ruler will suddenly take away one's house, one is hardly likely to indulge in any activity that may incur his wrath.

In the twelfth century the Crusaders caused consternation in Byzantium as they passed through on their way to the Holy Land, exacerbating the age-old tensions between east and west. These came to a head with the sack of Constantinople in 1204. Byzantium survived another two hundred years, but was fatally weakened and finally fell to the Turks in 1453.

Such sociological factors are sufficient to explain why science did not arise in Eastern Christendom, and it seems that these are more important than any theological differences.

An instructive example of the effect of sociological factors on intellectual activity is provided by the contrast between the English, French and Spanish colonies in north and central America on the one hand, and the Dutch colony in South Africa on the other. In America, there was from the first a thriving intellectual activity, with printing presses and newspapers, and great Colleges and universities were founded within a few decades of the arrival of the colonists. Mexico was conquered in 1521, and by 1553 had a university. In North America, the colonists arrived in 1619, and Harvard was founded in 1636. In South Africa, on the other hand, everything was controlled by the Dutch East India Company, and profit was the only motive. There were no printing presses, newspapers, colleges or universities. The Church was also partly to blame for this situation, because they insisted that their ministers be trained in Holland, and were not willing to establish Colleges in South Africa.

 Islam and Science

The wisdom of ancient Greece was transmitted to Europe by the Arabs. They saved and copied the Greek manuscripts, and published extensive commentaries on them. It was just these works of the Greeks that had such a seminal influence on the Middle Ages and profoundly modified European thought. The Arabs made important advances in may areas, notably in algebra, optics and ophthalmology. From the eighth to the fourteenth centuries, astronomy, optics, physics and medicine were far more developed in Islamic countries than in Western Europe. Arabic astronomers, to take one instance, had so improved the Ptolemaic system that it was mathematically equivalent to the Copernican system, although it was still geocentric. And yet the lead was lost in one area after another as the West surged ahead and Arabic science decayed.

We may well pause and ask ourselves what would have been the consequences for world history if they, and not the medievals, had developed our modern scientific knowledge of the world. It was one of the most monumental failures of history. They had a start of five hundred years, and a great Empire stretching from Cordoba to Baghdad. What was missing? It is simply that Islamic theology emphasises the freedom of Allah at the expense of His rationality, so that their grasp of the order of the world is not strong enough for science to develop.

It is also part of Muslim belief that scientific research should not be undertaken unless it can be shown that it will lead to a useful practical result. This error appears again in Marxism. At first it sounds plausible enough, even praiseworthy. Scientific research is very expensive, so why should society pay for it if it is not going to produce anything useful?

This argument is based on a misunderstanding of the very nature of scientific research, which can only develop in accord with its own internal criteria. It cannot, except in a very general way, be directed by external criteria, however laudable they may be. Scientists want to find out about the world; this is their motive and should be their only reward. If Roentgen had been interested in helping medical diagnosis he would never have found X-rays. If Madame Curie had started by looking for a cure for cancer she would never have found radium. As in these examples, it often happens that after the scientist has found some new property of the world, it is found to have great practical value and can be used to benefit society. Scientists welcome this, but the prospect of such applications cannot be allowed to affect the conduct of their research.

The reason why modern science never developed in Muslim countries is thus a theological one. They need European science and technology, and are willing to pay for it. Unfortunately however, that very science is alien to them as it is based on Christian beliefs about the world that they cannot share. There are of course many eminent Muslim scientists, but most of them have been trained in Western countries and so have come to share implicitly those Christian beliefs about the world on which Science is based. There do not as yet seem to be many indications that science has really taken root in Muslim countries.

References

M. Clagett, The Science of Mechanics in the Middle Ages. Madison, 1959.
A.C. Crombie, Augustine to Galileo, The History of Science 400-1650. Falcon, 1952.
A.C. Crombie, Robert Grosseteste and the Origins of Experimental Science 1100-1700. Oxford, 1953.
C. Dawson, Progress and Religion. Sheed and Ward, 1929.
C. Dawson, Religion and the Rise of Western Culture. Sheed and Ward, 1950.
E.Gilson, The Spirit of Medieval Philosophy. Sheed and Ward, 1936.
E. Gilson, The History of Christian Philosophy in the Middle Ages. Sheed and Ward, 1954.
J. Gimpel, The Medieval Machine. Pimlico, 1992.
E. Grant, Physical Science in the Middle Ages. Cambridge, 1977.
E. Grant, Planets, Stars and Orbs: The Medieval Cosmos 1200-1687. Cambridge, 1994.
F. Heer, The Medieval World. Wiedenfeld and Nicholson, 1961 (Ch. 12).
T.E. Huff, The Rise of Early Modern Science: Islam, China and the West. Cambridge, 1993.
S.L. Jaki, Science and Creation. Scottish Academic Press, 1986.
S.L. Jaki, Uneasy Genius: The Life and Work of Pierre Duhem. Martinus Nijhoff, 1984.
S.L. Jaki, "The Physics of Impetus and the Impetus of the Koran." "Science and Censorship: Helene Duhem and the Publication of the Systeme du Monde." Chapters 9 and 11 in The Absolute Beneath the Relative. University Press of America, 1988.
S.L. Jaki, Reluctant Heroine: The Life and Work of Helene Duhem. Scottish Academic Press, 1992.
S.L. Jaki, "Medieval Christianity: Its Inventiveness in Technology and Science." Article in: Technology in the Western Political Tradition. Ed. M.R. Zinman. Cornell U. Press,1993.
D.C. Lindberg (Ed), Science in the Middle Ages, Chicago, 1978.
J.A. Weisheipl. The Development of Physical Theory in the Middle Ages. Sheed & Ward,1959.
A.N. Whitehead, Science and the Modern World. Cambridge, 1926.

God, Aquinas, and Dawkins: The Origins of Science in Christian Europe

Science and Belief – The Origin of Science in Christian Europe

The following three posts contain excerpts from 8 lectures given by Peter Hodgson, a fellow of Corpus Christi College, Oxford University, England, where he is head of the Nuclear Physics Theoretical Group of the Nuclear Particle Physics Laboratory.  He has written 10 books on nuclear physics, 300 research articles and many popular articles on theology and science.  These lectures were first given at the University of Oxford in 1996 and 1998.

Why did science develop in our civilisation and not in any of the other great civilisations of the past? This is a complicated historical question that can be approached by listing the conditions that seem to be necessary for the rise of science and then seeing to what extent they are present in the different civilisations. If we find that the conditions necessary for the rise of science are present in only one civilisation then we have as full an explanation as it is possible to have for a historical phenomenon. We cannot of course expect to understand or explain the detailed history, for this depends on the presence of men of genius and other external circumstances.

If we think about what is needed for the viable birth of science, we see first of all that it needs a fairly well-developed society, so that some of its members can spend most of their time just thinking about the world, without the constant preoccupation of finding the next meal. It needs some simple technology, so that the apparatus required for experiments can be constructed. There must also be a system of writing, so that the results can be recorded and sent to other scientists, and a mathematical notation for expressing the results of measurements in numerical form. These may be called the material necessities of science. Since they may be found to a greater or lesser degree in most of the major civilisations of antiquity, we must look elsewhere for the answer to our question about the unique birth of science.

If the answer does not lie in the material conditions, we must seek it in the realm of ideas. Is it not possible that whether science develops or not depends on the attitude of the people to the material world? We can imagine that certain attitudes would prevent anyone thinking about the world in a way likely to lead to a scientific understanding, while others might at least provide a fertile soil for its growth. The type of thinking carried out in the early stages of science is done by people who share the ideas and beliefs of their civilisation. It is only later when science is well-established that specialised languages and modes of thought grow up and are taught to students and young scientists.

If we think about science and the attitudes that are likely to help its growth we can see first of all that it is essential for people to be interested in the material world. This implies that they must believe in some sense that it is good, so that it is worthwhile and respectable to try to find out more about it. Some people have thought that matter is evil, and that we must have as little to do with it as possible. Some early mystery cults taught that the world is evil and transitory, so that perfection may be attained only by turning away from the things of this world towards the eternal spiritual realm. If you believe that, then there is no possibility at all that you will become a scientist.

Another essential belief is that matter is orderly, that it behaves in a consistent and rational way. This means that if we observe and measure something one day, we will get the same results if we do the same thing on another day, or at another place. If we did not get the same results, if things behaved in a chaotic or random way, it would be impossible to build up a body of knowledge and science would be impossible. Unless we believe that there is an order in nature we will never take the trouble to find out what it is.

Concerning the order in nature, there are two possibilities. We may believe that the order in nature is a necessary order, that the material world could not be made in any way except the way it is in fact made. If we believed this, we might then think that the order of nature can be discovered by pure thought, that science can be developed in much the same way as mathematics. Many people have indeed tried this, and have not got very far; their speculations turn out in the end to be either trivial or wrong. We know that the only way to find out about the world is by controlled observation and experiment, and this is not encouraged if we believe that the order of the world is a necessary order.

The other possibility is that the order of the world is one of many possible ones. In other words we could assume that the order is contingent, that it depends on something else, that it could be other than it is. If we believe this, then the only way to ascertain that order is by observation and experiment, and thus the way is open for the development of science.

Another requirement for the development of science is the belief that the whole enterprise is a practicable one. We must believe that the order in nature is in some degree open to the human mind, that if we try hard enough we can discover some of its secrets. If the order in nature is hidden from the human mind, if there is no way of discovering it, then there is no point in trying to find it.

To sum up so far, we can see by considering the nature of science that it can grow in a civilisation in which the people believe that the world is good, or at least morally neutral, that it is rational and orderly, that it is contingent in the sense that it could be other than it is, and that it is apprehensible by the human mind.
These beliefs are essential, but they are not enough on their own. Scientific research is difficult, and nature does not readily yield its secrets. There needs to be a strong motivation to carry the scientist through all the failures and disappointments that inevitably come his way. Without this we might never get down to work, even though we recognised the theoretical possibility of attaining some knowledge of the world.

Another important characteristic of science is that it is a communal endeavour, the work of many minds. Every scientist builds on the work of his predecessors and shares his results with his colleagues. If scientists kept their results secret, the knowledge they gained would die with them and an extensive coherent body of knowledge would never be established. The scientist must therefore believe that whatever knowledge he gains is not his alone, but must be shared with the whole community.

These are the main beliefs that must be held by the whole community before science can even begin. They need not be held consciously and explicitly, in the sense that they could write them down in an orderly list. Many of them are usually held unconsciously or implicitly. They are to us so obvious that we would never even think of formulating them. They are part of the very fabric of our thought and form the way we look at the world.

Yet when we do think about them we realise that they constitute a very special set of beliefs that is by no means universal in human history, In fact if we examine the beliefs of past civilisations we find that many of them are quite different from those that we have seen are essential for the development of science. The very special set of beliefs about the material world that is needed for the growth of science did exist in Europe in the seventeenth century and this is why science as we know it developed at that time. But what is the origin of those beliefs, and why were they present at that time? To answer this questions we must go back to the beginnings of our civilisation.