© Colin W. Mitchell, Ph. D.
Binfield, England

PRE-CONDITIONS IN THE WESTERN WORLD-VIEW

Evolutionary theory could only gain acceptance where certain basic assumptions about the cosmos, and certain socio-economic conditions, themselves largely a result of those assumptions, were present. Two such assumptions were: a. that the universe was rational and governed by unchanging and predictable natural laws in which the linkage of cause and effect was automatic and observable, and. b. that ethical questions were separate from scientific and that the latter could be pursued without reference to the former.

The belief in a rational universe derived from Hebrew and Greek roots which saw it as created and regulated by rational and knowable deities. Beyond this, these two world-views differed profoundly. Hebrew religion was monotheistic and required absolute moral response. Greek religion was polytheistic and required reason and moderation to approach a pantheon of anthropomorphic and sometimes inharmonious deities. The former gave rise to a dominantly ethical and religious, and the latter to a dominantly rational and scientific, world-view. This difference had long-term repercussions in the reception of the evolutionary theory.

Attempts have been made to synthesize the two. The final pre-Christian endeavour in this direction was that by Philo of Alexandria (c20BC-AD50). Philo was a devout and learned Jew who was also deeply imbued with Greek culture, although as a Platonist the tendency of his philosophy was away from observational science.¹ His chief aim was to recommend Judaism to the respect, and if possible the acceptance of the Greeks. His method was to use a twofold interpretation of the Scriptures the literal and the allegorical. He believed that the literal must be held fast, but sometimes the allegorical gave a truer sense. He allegorized Scripture to make it speak the language of Greek philosophy. Perhaps his best known allegory, because it is a defence of the use of pagan philosophy in Hebrew and Christian theology, is the one concerning the newly emancipated Jewish slaves who borrowed or asked jewels of the Egyptians before marching eastwards. Egyptian, explains Philo, means Greeks; and since jewels are precious possessions, they represent the precious Greek philosophy; that the Jews asked for and took them means that any child of God may make use of Greek philosophy.² Such a far-fetched interpretation underlines the difficulty of harmonizing the two systems.

Philo also developed the Stoic doctrine of the logos as a cosmic principle of order and harmony, seeing it as the pattern or power by which God impinged on the world, and the unifying principle behind the diversity of natural phenomena. Although a contemporary of Christ, his writings completely omit the changed concept of the logos which resulted from its application to Jesus as both the Creator³ and the one who 'was made flesh and dwelt among us'.⁴

After Philo, the task of harmonizing the Scriptures with science fell on the Church, while Eastern Judaism moved farther and farther away from the direction which the New Testament had taken up in unfolding the spiritual elements of the Old.

The acceptance of Christianity as the religion of the Roman Empire was accompanied by a continuing decline in scientific effort. This seems to have been largely due to the influence of Augustine of Hippo (AD354-430). His immense theological prestige, derived from his systematization of Catholic doctrine, brought acceptance of his scientific views. These were derived largely from Neo-Platonism, a philosophy developed by Plotinus (AD207-270). As its name suggests, its main emphasis was on reviving Plato's philosophical ideas. These were distinctive in seeing introspection as the path to truth and in disdaining scientific observation. Plato saw mathematics as superior to other types of study because it was abstract and underived from anything in the visible world. Through Augustine's influence Neo-platonism came to dominate the Christian view of the natural world.

It viewed the world as a circle with man ('microcosm') at the centre and other circles concentrically outside this, m order: the four humours, the four seasons, and the four elements, the extremity being the universe ('macrocosm'). All were bonded together into a synthesis as shown here. The centre contains the 'Idea', or 'Form', which is almost personified. This controls the natural world which, like all matter, is evil. This is almost personified. Matter is evil. It may at times break away from Idea and become involved in discord, strife, or even chaos, from which it can only return by further contact with Idea. Thus mankind must seek to free itself from contamination with matter.

The natural creation was seen as only a background to the human spiritual pilgrimage, not meriting independent enquiry. This view remained dominant for over 1,200 years, until the seventeenth century. It had the effect of subordinating scientific observation to ancient authority, causing it to be neglected.

The reversal of the medieval world-view was largely due to Thomas Aquinas (1227-74). He did two things. First, he completed the work of his teacher, Albertus Magnus, in reintroducing Aristotle into the University of Paris, then Europe's leading intellectual centre. Aristotle differed from Plato in being a keen observer, and some of his observations of phenomena such as climate and animals have remained of value to this day. His reintroduction reestablished observation as a path to scientific truth. This met severe theological opposition because of the threat it posed to the Augustinian synthesis.

Secondly, Aquinas contended that observations of nature could proceed independently of faith because human reason was unaffected by the Fall. This made reason autonomous, allowed unfettered thought, and brought scientific advances, but tended to detach science from ethical moorings. This concept of autonomous human reason paved the way for the Renaissance. This began in Italy in the fourteenth century, reviving the intellectual perspectives of the classical age. Science became a popular cultural activity. The Renaissance was not anti-religious, but it revived the distinction between religious and secular knowledge which had become obscured in the Middle Ages. The medieval world had seen natural phenomena as secondary and derivative aspects of spiritual realities. Even Aquinas' reintroduction of Aristotle had made relatively little impact because it only formed a part of his total theological system. As time passed, the formulation and verification of scientific hypotheses gradually reduced the role of supernatural agencies. Explanations were strictly in this-worldly terms. This reduced the practical utility of religion although many scientists still found their inspiration from it.

The Reformation, with its return to Bible study, revived the distinction between Christianity and culture which the medieval synthesis had obscured. It also encouraged a wider range of independent thought. This contributed to the advance of observational science and free enquiry rather than appeals to the classics. Far from emphasis on the Bible being restrictive on scientific thought, it is notable how many prominent scientists had a Protestant background. When the Royal Society, for instance, was established in 1662, 90 per cent of its foundation members were Puritans or had Puritan connections.⁵ No conflict was seen between science and Scripture.

The Enlightenment was the philosophical movement which followed in the eighteenth century. It came in the aftermath of the debilitating seventeenth century wars of religion, which had sunk the legal and moral authority of religious institutions and functionaries to a low ebb. It stressed the importance of reason and the critical reappraisal of existing ideas and social institutions. It witnessed significant scientific advances, notably Newton's theory of planetary motions. Newton was devoutly religious and wrote extensively on the Bible. But one consequence of these scientific discoveries was to emphasize a mechanical view of causation in nature. This tended to diminish the role of the supernatural in the popular estimation.

The Enlightenment further accelerated a separation of science from religious moorings by breaking the basic Christian consensus which the Reformation crisis had left fragile but intact. Christianity became not only ignored but actively contradicted. Critics such as Voltaire and Hume, although few in numbers, had a wide influence. The Christian world-view, although it remained dominant, ceased to be normative. The Enlightenment left a legacy of secular humanism, which has generally persisted as a dominant world-view to this day.⁶The effect of these historical processes was to leave an intellectual environment in which the Church had lost scientific influence and there was a weakened linkage between religious truth and scientific discovery. This further prepared the ground for the acceptance of the evolution theory.

THE BEGINNINGS OF THE EVOLUTION THEORY

We must now turn to the origins of the theory itself. The first person to set down an evolutionary explanation of the origin of species was Georges Buffon (1707-88). He saw geological strata as representing historical stages, and his idea that certain species had been lost allowed the study of palaeontology to proceed with a ready-made explanation of the large gaps between fossil and living forms.⁷

Lamarck (1744-1829) sought to discover a universal law which would incorporate all the various sciences into one great systematic materialistic framework. His central theme was that there were 'subtle and ever-moving fluids' which were 'excited' and by which the organs of animals were gradually adapted to their environment. These characteristics were then passed on to their offspring. He also believed that the continents had been built up by inundations of the sea and that nature had had unlimited time to accomplish her task of transforming living organisms. His view was thus materialistic. It differed both from the Darwinian theory and modern science in its belief in a speculative animal biochemistry which was able to effect the inheritance of acquired characteristics. For these reasons it has only historical interest today.

Georges Cuvier (1769-1832) became an authority on living and fossil animals. He rejected Lamarck's ideas on evolution, claiming that the fossil evidence did not show a consistent slow transformation of one species into another. He believed in a series of catastrophes after each of which animals were replaced by newly-created species.

Erasmus Darwin (1731-1802), grandfather of Charles, set out ideas of evolution similar to those of Lamarck in his book Zoonomia.⁸ He believed that the universe had been formed from an initial explosion (analogous to the modern idea of the 'Big-Bang', which is conceived to have been the mighty explosion of matter which started the universe), and a belief in the continual transformation of animals from one species to another by adapting to their environment in a purposive way, without supernatural direction. His views were known as Darwinism even before his grandson Charles was born, but did not receive wide acceptance at the time. This was because they were not backed by a body of evidence such as that which Charles later sought to provide.

Robert Malthus (1766-1834) foreshadowed evolution theory with his study of populations.⁹ Since humans can double their numbers at least once in twenty-five years, and since the supply of food can only increase in arithmetical ratio, it naturally follows that increase of population must always be checked by lack of food. But, except in cases of famine, this check is never operative, and control of population growth is due to 'moral restraint, vice, and misery'. The constant increase in population beyond the means of subsistence, drives down wages, increases the price of food, and has the effect of lowering the marriage and birth rates. This situation in turn stimulates renewed agricultural enterprise, increasing the means of subsistence. This swells the marriage and birth rates, raising the population, once again provoking a shortage of food, and so on. There are limits beyond which no population can be varied by breeding, and so the human race will not progress towards a perfect state but will be trapped in this cycle. When Darwin later came to formulate his theory, he was strongly influenced by this argument, but reached an opposite conclusion from it. Malthus believed that the only solution to population pressures on resources was moral restraint, which was also a Christian duty. Darwin, by contrast, concluded that the struggle for existence would enable the fittest to survive and produce a continual progression of improving species. He thus used Malthus's idea to point to conclusions almost the reverse of those which Malthus himself advocated.

In 1844 Robert Chambers published anonymously a book entitled Vestiges of the Natural History of Creation in which he set out evolutionary views, although he stated that the process was in control of 'the One Eternal and Unchangeable'. Today this would be called theistic evolution. The book was very popular. Four editions appeared in the first seven months and then it came out annually for the next ten years. It was strongly criticized at the time, but Darwin, in later editions of Origin, said it was a valuable precursor of his own work in calling attention to the subject, removing prejudice, and thus preparing the ground for analogous views.¹⁰

GEOLOGICAL PRECURSORS

The biblical time scale of a few thousand years appeared far too short for evolution to have operated. A time in millions of years was provided by the Uniformitarian Theory of geology.

The eighteenth century had seen a debate between Neptunism and Vulcanism, over the question of whether the oceans or volcanoes were the dominant force which had moulded the landscape. The former was advocated by Abraham Werner (1750-1817) who emphasized the mechanical and chemical action of flood waters. James Hutton (1726-97) taught the Vulcanist theory which emphasized the importance of heat on the earth's formation. Because both these theories involved vast, rather rapid, changes they were called Catastrophist. Hutton was also the original proposer of Uniformitarianism. This taught that sedimentary strata were laid down slowly over long periods by the ordinary forces of rain, frost, moving water, etc., acting as they do today. Hutton claimed that exposed strata are weathered and eroded into lakes or the sea, eventually settling to form new strata. These could be hardened by pressure and heat and uplifted to form new mountain areas, to commence the cycle all over again. This continuous cycle of events would take an immense time millions of years.

Charles Lyell (1797-1875) first published his influential three-volume Principles of Geology, advocating the uniformitarian theory, in 1830. The book was immediately popular and in twenty years had led to its general acceptance and a rejection of Catastrophism. He was working on the twelfth edition when he died. It remains the basic background to geological teaching today. Its central theme is the uniformity of geological processes. In his conclusion to Volume 1 Lyell¹¹ categorically rejects a catastrophist view, but on moral rather than scientific grounds:

Uniformitarianism was made even more acceptable by the 'Tranquil Theory', first suggested by the Swedish botanist Carolus Linnaeus (1707-78) and introduced to the British public by John Fleming, Professor of Natural Philosophy in Aberdeen, in 1826.¹² This claimed that the Mosaic narrative taught only a gradual rise of flood waters, destroying neither soil nor vegetation. It was therefore quite reasonable to suppose that no traces of a biblical Flood remained.

CHARLES DARWIN

Charles Darwin was born in Shrewsbury on 12 February 1809, the same day as Abraham Lincoln. His maternal grandfather was Josiah Wedgwood, maker of the famous Wedgwood chinaware. His paternal grandfather was Erasmus Darwin, his father was a highly successful physician. As a young man Charles showed promise and aided his father in his duties. In 1825 he went to Edinburgh to study medicine. But he took no interest in his studies and was a failure. Looking for an alternative he was recommended to study theology. He went to Cambridge, but though he completed his degree, his interests had again drifted away and he decided not to be ordained. He later admitted that his time at Cambridge 'was wasted, as far as the academic studies were concerned, as completely as at Edinburgh and at school.¹³

He became interested in geology in 1831 during his last year at Cambridge when he became friendly with Adam Sedgwick (1785-1873), the professor of Geology, who in that same year became a Fellow of the Royal Society and President of the Geological Society. Under Sedgwick's influence he was first a Catastrophist. He also became friendly with the Professor of Botany, the Reverend John Stevens Henslow, who recommended him for the post of naturalist on the Beagle, which was sailing to make more accurate navigational charts. He accepted the post. The voyage had a profound effect not only on his own life, but upon the whole subsequent history of science.

Just before he sailed, Henslow gave him a copy of the first volume of Lyell's Principles of Geology with the advice that he should not believe its contents! When reading the book, however, he became an enthusiastic convert and based all his interpretations of the geological formations he examined during the voyage on the uniformitarian theory.

His rapid acceptance of this theory is particularly strange as he later commented in his diary that 'everything betrays marks of extreme violence'. Similarly, having experienced an earthquake in Chile, he was particularly impressed by the enormous changes that could occur in a short time. However, in his publications he tended to play down earlier observations which conflicted with uniformitarianism.

Darwin was vigorous, and during the Beagle expedition displayed remarkable endurance, on one occasion walking fifteen miles on a hot day without food or water. He did, however, suffer considerably from seasickness on the voyage, and the illness he experienced during most of the rest of his life seems to have started at this time. Various biographers have attributed this ill-health to eye-strain, glandular disturbances, heart trouble, and the bite of an insect in South America; but in recent times it has become generally accepted that it was mental rather than physical. It seems more than a coincidence that it began in 1837 when he started the work which culminated, after much procrastination, in The Origin of Species twenty-two years later. It was perhaps most likely due to a combination of fear of hostile criticism, a desire for honour, and the psychological tension between the logic of his theory and his lingering religious convictions. His wife was very religious, and although they lived in harmony this was a difference between them.¹⁴ From 1842 he passed his time at Down, Kent, as a country gentleman, devoting himself unremittingly, in spite of his ill-health, to his estate and to science. His second major book The Descent of Man was published in 1871. This derives the human race from a hairy quadrumanous animal belonging to the great anthropoid group, and related to the progenitors of the orangutan, chimpanzee, and gorilla. He died in 1882 and was buried in Westminster Abbey.

He is mainly remembered as the great leader of evolutionary biology. Though not himself the originator of the evolution hypothesis, nor even the first to apply the conception to particular plants and animals, he was undoubtedly the first thinker to win it a wide acceptance among biological experts. By adding to the crude evolutionism of Erasmus Darwin, Lamarck and others, his own idea of natural selection, he supplied the process with a convincing mechanism. This raised it at once from an interesting hypothesis to a veritable theory. His success was aided by his kindliness, honesty of purpose, devotion to truth and attachment to his friends, which made him as remarkable on the moral and emotional as on the intellectual side of his nature.

When considering the contributions of Lyell and Darwin, however, it is important to notice a point which applies to both a tendency to make sweeping generalizations from rather limited data even in the face of contradictory evidence.

Concerning Lyell, Stephen Jay Gould, Professor of Geology at Harvard University, a prominent evolutionist, has commented:

Darwin is vulnerable to similar charges. First, he argues that the absence of 'missing links' between fossils are due to the imperfection of the record. Secondly, his rapid acceptance of Lyell's uniformitarianism conflicts with his observations. Then, having experienced the earthquake in Chile, he was particularly impressed by the enormous changes that could occur in a short time.

THE PUBLICATION OF ORIGIN AND ITS AFTERMATH

The publication of The Origin of Species was uncertain until the last moment. John Murray, the publisher, was induced by Lyell to go ahead with it, but retained serious doubts both of its scientific value and of its commercial viability. Darwin was himself very uncertain of its success and gave Murray complete freedom to withdraw from publishing the book, saying ' . . . though I shall be a little disappointed, I shall in no way be injured'.¹⁶ When correcting the proofs, Darwin rewrote so much of it that he offered to pay Murray for the heavy costs of the amendments.

It finally appeared on 24 November 1959. The 1,250 copies printed sold out on the day of publication. This is not, however, as impressive as it sounds since they had all been taken up by dealers and book agents at Murray's annual sale a few days before.

The theory of evolution proposed by the book challenged the Bible account of origins in a way that no previous scientific theory had done. It was soon popularized by writers such as Charles Lyell, Herbert Spencer, Roderick Murchison, and Thomas Huxley. Huxley's nine-member 'X' Club assisted the process through its influence in appointing men to key university posts. In Germany the evolution message was spread by Ernst Haeckel and in America by Asa Gray.¹⁷

The critical point in its general acceptance is regarded as having come at the debate between Thomas Huxley and Bishop Samuel Wilberforce at the British Association for the Advancement of Science in Oxford in 1860. According to one account, Wilberforce finished his speech by enquiring of Huxley whether it was 'through his grandfather or his grandmother that he claimed his descent from a monkey?' Huxley murmured to Sir Benjamin Brodie sitting next to him, 'The Lord hath delivered him into mine hands', but refused to speak until the crowd was calling for him. Once on his feet he defended Darwin's views, but took advantage of the bishop's distasteful jibe by adding that if the choice was between an ape for a grandfather or man who misused his eloquence to introduce ridicule into a grave scientific discussion then he unhesitatingly affirmed his 'preference for the ape'.¹⁸

The exact words of both speakers are now uncertain but their effect is not. The encounter came to be viewed as a critical confrontation, where the Church had appeared to disadvantage and science had earned the right to lecture it.

Nevertheless, it was not unquestioned. Writers such as Cuvier, Linnaeus, and Richard Owen had always been sceptical of trans-specific evolution, and this scepticism continued in spite of its strong advocacy by Huxley, Herbert Spencer, and others. Also, the undesirable moral implications of the theory had been perceived from the very beginning.

Adam Sedgwick wrote to Darwin:

Sedgwick believed that once science ceased to attribute the laws of nature to the will of God, but rather set them up as independent causes, then all sense of divine plan would be lost. There was a necessary link between natural laws and divine power. He continued:

In the light of some of the events of the twentieth century, these words sound prophetic.

Sedgwick's fears were shared by Thomas Carlyle ²⁰ and by some members of the Brethren Movement and the Free Evangelicals. These groups, among others, saw it as counter to biblical faith, though they were prepared to countenance the idea of an old earth by accepting the Gap Theory.²¹

CONDITIONS IN VICTORIAN BRITAIN FAVOURING THE ACCEPTANCE OF DARWINISM

Victorian Britain proved to be fertile soil for the widespread acceptance of Darwinism within about twenty years. There were a number of reasons for this. The intellectual climate was favourable. People accepted that most phenomena had natural causes, and Darwin's explanations, apparently supported by a mass of new and fascinating evidence, appeared scientific. The theory supplied a missing key to biology, which had been relatively backward in relation to other sciences. Social conditions were also favourable. The long peace following the Napoleonic wars had made for general optimism. This encouraged a belief in the inevitability of upward progress, even if it was gradual and spasmodic. The success of the flee-market economy seemed to support the idea of natural selection. Also important was a relatively prosperous and independent scientific community with opportunities and inclination for worldwide travel and investigation.

Darwinian theory also had some backing from religious sources. The attack on the Bible from the Higher Critical angle had converted many Churches to the idea that religion had evolved from primitive origins. There was some popular condemnation of what appeared to be Christian prejudice against science. Wilberforce's stance at the British Association debate was seen as unscientific. Disbelief in evolution became associated with theological prejudice. This was probably helped by the comforting belief that a sinful act was not now something wicked and blameworthy, but a relic of animal ancestry.

MENDEL'S IMPACT ON THE THEORY

Gregor Mendel (1822-84) was an Austrian priest, subsequently becoming an abbot, who conducted numerous cross-breeding experiments on pea plants. He discovered that various characteristics (height, colour, etc.) appeared in first and second generation plants in accordance with simple mathematical proportions. Although the exact mathematics of these proportions has since been challenged, the general relationship has not.

But from the point of view of the evolution question, his other discovery is the most important. This was that although two parents pass on a variety of characteristics to their offspring, these characteristics cannot go beyond the limit of what was in the original genes. No amount of breeding can produce species with completely new characteristics. The heritable characters are stable and constant. Although they can skip one or more generations and then reappear, when they do they are just the same as they were before.

Darwin believed that evolution came about through continual small differences between individuals, the best of

which were preserved by natural selection. Mendel's results confine this possibility within the limits of discrete groups. This was acknowledged by geneticists, and led to their proposing another mechanism. This relies on the fact that a very small proportion of offspring is noticeably different from the parents. These are called mutants. Their appearance is due to significant alterations of the genes of the parents. Although badly damaged cells are aborted, slightly damaged cells may live but possess some abnormality or disfigurement. It is these mutants which evolutionists claim may occasionally, under changing environmental conditions, be better adapted than the parents and thus propagate successfully. With further mutations, it is presumed that a new species will appear. This has so changed the basis of Darwin's theory that it is now called Neo-Darwinism. The possibility that such mutations can explain evolution is considered further in a remarkable book by Lee Spetner.

SUMMARY

It is impossible to understand the impact of the theory of evolution on our society without considering its intellectual origins. It represents a culmination of a long history of thought. Its roots can be traced to the classical dichotomy between Greek science and Hebrew religion. Throughout history there has been a persistent urge to find a unitary philosophy which synthesized these two, but a continuing inability to achieve it. Attempts at synthesis were made by such thinkers as Philo, Augustine, and Aquinas. The first twelve centuries of the Christian era were characterized by the wide acceptance of Augustine's theological system which, while considering science to be the handmaid of theology, in fact discouraged the observation of nature.

The Renaissance was in part a reaction against this, and the subsequent developments of Western science have established and maintained its separation from theology. This separation was one of the factors facilitating the acceptance of the evolution theory by marginalizing theological objections.

The evolution theory represented a culmination of the work of a line of scientists among whom Buffon, Lamarck, Cuvier, Malthus, and Lyell are notable. Darwin's Origin appeared in 1859. It faced considerable criticism at first but won general acceptance through the advocacy of writers such as Herbert Spencer and Thomas Huxley, and through the generally favourable intellectual and social conditions in Victorian Britain, perhaps the most advanced society of its day.

The theory had to be modified in the light of Mendel's discovery of the genetic limits to heritable change within a population. It is now widely held in the form of Neo-Darwinism. This believes in evolutionary change through the natural selection of living forms possessing favourable mutations.