Anthony M. Ludovici
The Eugenics Review 25, 193334, pp. 147155
- p. 147 -
Turning from these a priori conclusions to fact, we find not only that these early cultures were extremely harmonious, but that their power and influence have been so great that our own culture owes what little beauty and harmony it possesses entirely to them. A further interesting fact is that all these early cultures arose in naturally or artificially confined areas in islands like Crete and Japan, peninsulas like India, Greece, and Italy, naturally enclosed areas like Peru, Mesopotamia, and Egypt, and more or less artificially enclosed areas like China and Palestine where broad-mindedness, the universal brotherhood of man, the love of one's neighbour, and other superior forms of claptrap were unknown. Furthermore, we know that where intercourse with the outside world, with the neighbour, is checked, the secluded people are condemned to inbreeding and close inbreeding; indeed, in the only cultures that have left a permanent mark on the world, we find not only inbreeding, but also a strong conscious tendency to keep apart, to segregate. This tendency caused not only a frontier of prejudice to spring up between the secluded nation and the world, but also a series of frontiers within the nation itself, dividing off classes and castes, so that within the inbred mass, smaller inbred classes were formed.
It would seem as if men who had acquired a set of special qualities possessed an instinct to keep aloof from anyone who could adulterate these qualities. In healthy cultivated man, this instinct is so pronounced as to be a matter of common knowledge. Even among the primitive peoples, it has been noticed by scores of observers. Among the peoples principally responsible for civilization the Egyptians, the Jews, and the Greeks the abhorrence of the stranger was so great that the very word for stranger was a term of opprobrium. And each of these peoples was not only inbred but incestuous.
Can there be any connection between these sets of facts the fact that these peoples created our civilization, the fact that they lived in enclosed areas, and the fact that they were closely inbred and incestuous? There is a marked prejudice against consanguineous and particularly against incestuous matings in the modern world. Is it possible that like other superstitions, like the belief in the superiority of the psyche over the soma, it is based on ancient magic? If it is, it is important to get rid of it, because the people who were responsible for civilizing the world were probably greater than a people like ourselves who have left no stone unturned in order to decivilize it.
* The substance of a paper read before the Eugenics Society on July 18th, 1933.
Genetics of breeding
Breeding is the process of producing a new individual by the conjunction of two germ cells, male and female. In random-bred stocks, the hereditary equipment of the couple is different. Each contains factors or developmental determiners of a kind different from the other. In mixed breeding, therefore, one can picture the process of their conjunction as an intermingling of wools not only of different sets of colours, but of different quality; and, as in random-bred stocks there is always latent in the germ plasm much that is deleterious, we must imagine some of these wools as being diseased or morbid.
Mixed breeding from a pair taken at random in an unstabilized stock has three principal results. It may, by a stroke of luck, produce a new individual who is harmonious, i.e. who presents a symmetrical pattern, and who is free from morbid manifestations; it may, and usually does, produce an individual who is inharmonious; and if, by a similar chance conjunction to that which united the health-determining factors in the lucky individual, the ill-health determining factors happen to unite, it may produce an individual with some more or less grave morbid manifestation. It should, however, always be remembered that even the lucky individual who looks healthy and sound in a random-bred stock, bears in his hereditary equipment the deleterious elements common to the stock which produced his less-fortunate brothers.
In inbred stocks the hereditary equipment of the breeding pair is the same i.e. except probably for sex, each has the same factors for determining the characters of the progeny. Moreover, since inbreeding favours the mendelizing out of determiners for developmental defects, and since, in an inbred stock which has reached stability or become completely homozygous, morbidity-determining factors have been eliminated, the new individual, except in the case of a morbid mutation, is unlikely to be morbid. He is likely to be harmonious and healthy, his morphological characters afford some definite indication of his hereditary equipment, and the health and physical harmony of his offspring become a more or less calculable certainty if he is mated with his like.
If, however, inbreeding occurs in a stock hitherto random-bred, it must be obvious that, since deleterious factors are always latent in the germ-plasm of such a stock, similar morbid factors may be brought together by joining a male and female of the same family. This, it is true, quickly eliminates the "unlucky strokes," and purifies the stock. But the process may be expensive. Its expense will be proportionate to the amount of latent morbidity in the stock.
It is important to remember, however, that random-breeding and mixed breeding do not eliminate bad hereditary factors from a stock, but merely cover them up. While inbreeding does not create bad hereditary factors, but merely tends to bring them out.
This is roughly what science has to say about the two methods of breeding. It was all perfectly plain eighty years ago. If the biologists of the nineteenth century had looked at history and life, they would have seen that Nature was, as far as we can tell, almost everywhere striving by inbreeding to produce the desirable state of homozygosity, and had implanted instincts in Man and most beasts to that cited.
What about the actual practice of Nature and the breeder of animals? In the first place, we know that the closest inbreeding occurs in some plants for example, the common blue violet, garden beans, the many species of the small evening primrose in which the egg-cells are fertilized by pollen produced by the same individual. Self-fertilization is also the rule in wheat, oats, and the majority of other cereal crops the most important of cultivated plants. The process cannot, therefore, be attended by evil results, at least to these plants, otherwise they would not be with us to-day.
Turning to animals, we find in them no instinctive safeguard against incestuous mating. Reproduction in rats, mice, rabbits and other rodents, according to Dr. Briffault, takes place without any regard for relation-
According to Dr. A. C. Brehm, the nature of the troop among monkeys makes constant matings between the head of the horde and his daughters, sisters and other close relations wholly inevitable, and in fact among all polygamous animals, whether gorilla, wild boar, or elephant, the leading male must enjoy the favours of his daughters, grand-daughters, and great-grand-daughters, so long as he is able to keep other males away. Nor, as Huth points out, does the incest cease when he is at last turned out; because the first in the field will most probably be his own sons and grandsons.
A new, and recently authenticated, case of naturally determined incest, appears to have been discovered by the British Museum Expedition to the Gobi Desert in 1929, when a bird, the Eörnis Pterovelox Gobiensis, was found, which hatches twins at each birth, a male and a female, and these same individuals later mate and are monogamous. We also know the rabbits of Australia, the pigs of New Zealand, the cattle of South America all offspring of a few individuals let loose on the soil. According to Harnady a classical example of a stock of animals bred from only three ancestors is afforded by the red deer of New Zealand. The original three specimens were introduced from England in 1864, and only ten years ago the herd numbered 5,000. Yet they show no signs of disease but are indeed superior in vigour and constitution to the original parent stock.
The evidence from the practice of experienced breeders conclusively points to the best results being obtained from the closest inbreeding.
But, just as natural selection eliminates individuals which are the outcome of two polluted streams becoming confluent in consanguineous unions, so the wise breeder, imitating Nature's way, carefully weeds out unhappy specimens. If morbid or lethal factors still exist in the stock's germ-plasm, and they happen to come together from both sides in the mating of close relatives, then instead of a confluence of rivers of pure water, a confluence of impure streams occurs, which results in a stream doubly contaminated.
But it is remarkable that owing to the ethico-theological superstition against inbreeding and incest, bad and ignorant breeders have, until recently, always ascribed to close inbreeding per se, and not to the pollution of the continent streams, the disappointing results of their methods so much so, indeed, that not only Darwin, who consulted many such ignorant breeders, but countless other authorities, took it for granted that inbreeding must be bad, particularly as it was forbidden by the Table of Affinities.
Settegast, in 1868, in Germany, took an even stronger stand than Darwin against inbreeding, with the result, as Kronacher shows, that for fifty years nobody ever heard of a reputable breed of German cattle or horses. And it was only when de Chapeaurouge and Lehndorff reversed Settegast's
Apart from all theorists, however, knowledgeable breeders all over the world have from time immemorial practised inbreeding, accompanied by careful selection. As long ago as 1823, N. H. Smith, a famous breeder, long resident among the Arabs, wrote: "I cannot say how often an incestuous breed may be carried on before degeneracy occurs, as I am not aware of that being the case in any instance, and experience is in favour of breeding from son and mother, fattier and daughter." And it is this incestuous stock that has given our race-horses some of their finest qualities. The Clydesdale breed of horses, as Calder shows, is also closely inbred, 80 or 90 per cent. of the horses in the recent volumes of the Shire Stud Book going back in direct line to three stallions, living 60 or 70 years ago William the Conqueror, Lincolnshire Lad, and Matchless. Among dog-breeders, de Chapeaurouge produced a closely inbred stock of pugs with complete success. N. H. Gentry reports from America a successfully inbred stock of Berkshire pigs, while a Dutch landowner recently reared a stock of middle white breed without any evil results from one imported boar and two sows. Kronacher, starting with one male and three females (a mother and two daughters) bred a stock of ordinary goats, in and in for eight generations, without any loss of size, physical development, milking capacity, fertility or vitality. Indeed their fertility tended to increase. And he declares that in this case he practised no selection whatever.
In cattle the success of close inbreeding is so startling that Darwin felt compelled to suggest that some exception to Nature's supposed law against incest must have been made in their favour! The famous cow Restless came of the most persistent inbreeding. The bull Bolingbroke, with his half-sister Phoenix, produced the bull Favourite. Favourite, with his mother, produced the cow Young Phoenix, a celebrated animal. With his daughter, Favourite then produced the famous bull Comet. He was then put to his daughter's daughter, and again to his daughter's daughter's daughter. The product of this last union had 93.75 per cent. of Favourite's blood in her, and was put to the bull Wellington, who had 62.5 per cent. of Favourite's blood. This union produced Clarissa, an admirable cow, who with the bull Lancaster (having 68.75 per cent. of Favourite's blood in his veins) produced the celebrated cow Restless.
Such was the practice of Nature's experienced breeders when Darwin wrote the first authoritative book on breeding, and yet so great was the ethico-religious bias of the day that, although he recognized crossing as a cause of degeneracy, he concluded that too close consanguinity must lead to weakness, sterility and greater susceptibility to disease.
Overlooking a good deal of what experienced breeders said, and all the historical and anthropological evidence, other nineteenth-century scientists seem to have been influenced by the cases where the inbreeding of tainted stocks had, of course, led to bad results. Moreover, they performed experiments of their own, which, astonishing as it may seem, without exception proved that inbreeding was harmful, thus confirming the following of Darwin's findings:
(a) That the consequences of close inbreeding were loss of size, constitutional vigour, and fertility.
(b) That the crossing of animals and plants not closely related was highly beneficial and even necessary.
Recently these conclusions began to be doubted. In 1916 Professor Castle stated that he had successfully bred Drosophila, brother and sister, for 59 generations, without obtaining any diminution in either vigour or fertility. Moenkhaus crossed the same fly, brother and sister, for 75 generations, without harmful consequences. Hyde and Schultze achieved the same result with mice. Castle tried rats, and Popenoe guinea-pigs, and both concluded that no deleterious effects could be ascribed to the system of mating. King experimented with white rats, mating brother and sister regularly for 22 generations, and
Commenting on these experiments, Rice says: "These results lead to the very definite suspicion that the earlier investigators unconsciously selected the animals in such a way as to lead to the diminished fertility and vitality, or else even used defective Strains in their experiments." According to Crew, "Consanguinity itself is no bar to mating. If inbreeding results in disappointment, all that has happened is that that which previously was hidden in a heterozygous stock has now been brought to the surface. Inbreeding is only disastrous if the ingredients of disaster are already in the stock. If inbreeding exposes the undesirable, it equally thoroughly emphasizes the desirable, and the desirable will breed true when complete homozygosis in respect of these characters is attained." Thus to be successful, inbreeding must be attended with the most rigorous selection.
As a formula for the respective effects of inbreeding and out- or cross-breeding, I suggest the following:
Inbreeding canalizes and isolates health and desirable qualities, just as it canalizes and isolates ill-health and undesirable qualities. Cross-breeding conceals and spreads ill-health and undesirable qualities, and thus contaminates desirable stocks. But it also tends to improve poor or degenerate stocks at the expense of sound stock.
In discussing the problem in relation to Man, it is interesting to recall how far the endogamic instincts of cultivated human stocks led to intensive inbreeding within certain groups. In Egypt, in addition to the national endogamy which forbade mixing with the foreigner, incestuous unions prevailed both among the people and within the ruler groups. In the golden age of the Theban Empire, seven kings in the Eighteenth Dynasty married their sisters; in the Nineteenth all but three did so; in the Twentieth every king married his sister. Kings married their sisters in the Sixteenth, Thirteenth and Twelfth Dynasties, and as early as the Fourth. And when the Lagidae ruled Egypt, they could not afford to disregard this ancient custom. Thus Cleopatra, whose wit, beauty and intelligence are proverbial, was the daughter of a brother and sister, great-grand-daughter of another brother and sister, and a great-great-grand-daughter of Berenice who was both cousin and sister to her husband. Egypt declined only when her endogamic fences broke down.
Persia, strictly endogamic, had an incestuous royal house, and the Magian aristocracy married their mothers, daughters and sisters. According to Robertson Smith, the Phoenicians, and according to Périer the Assyrians, were regularly incestuous, as were also the Scythians and the Tartars. The Jews, also an endogamic people, were surrounded by nations who were all mating consanguineously for the sake of purity, and probably health, too. It is likely, therefore, that at least the aristocrats among the Jews also practised incest, in spite of the table of prohibited degrees. Incestuous practices are known to have been common in the Siamese aristocracy, among the Arabs who allowed them down to Mahomed's time, and among the Burmese, Cambodians and Mongols.
In Britain, as late as fifth century, we find Vortigern marrying his own daughter. Nor could the practice have been condemned, since the issue of this sinful union was none other than St. Faustus. According to Strabo, the ancient Irish married without distinction their mothers and sisters, and Heineccius tells us it was customary for the ancient Germans to marry their sisters. There is overwhelming evidence that the Peruvians were strictly endogamic. The proud Incas, refusing to mix their blood, married their sisters; and it is said that the soldiers and nobility customarily followed the royal example.
As to more recent instances of incest among human beings, I have collected accounts of no less than thirty primitive communities in which incest was practised
Thus we have seen that Man, like some of the animals, seems to have an instinct impelling him to canalize qualities acquired with pains. It seems as if it were a law of Nature, not, as Darwin thought, to have crosses, but to avoid them. Even in those tribes and races where incest is illegal, we often find the rulers or chiefs deliberately infringing the prohibited degrees to keep their blood pure. For instance in Burmah, marriage with half-sisters is forbidden, but the King always marries his half-sister. In Siam the people may not marry nearer relatives than third cousins, but the King may marry his sister and his daughter. The same is true of the higher classes in Cambodia, of the chiefs of the Marianne and Ladrone Islands, in Hawaii, Nukuhiva, Tahiti and Madagascar, and it was also true of the Northern American Indians of New England. In fact, as the Kalmucks say, "Great folk and dogs have no relatives." Nor are the people addicted to these practices degenerate or diseased; on the contrary, all travellers comment on their great vigour and beauty.
There is even a case of a people living, more or less in a state of Nature, who, according to Sir Basil Thomson, are actually benefited by inbreeding. Among this people the Fijians those stocks which have adhered to the ancestral custom requiring first-cousin marriages, are very much the superiors from every physical point of view of those who no longer practise, or else forbid, first-cousin marriages, and the latter are even said to be dying out, while the former have a higher birth rate and greater vitality.
According to Junghuhn the Bataks of Sumatra, who also habitually marry their first-cousins, are the finest people in the Indian Archipelago. The chiefs in Polynesia and New Zealand have all been noticed for their superior height, looks and vigour. And throughout Polynesia the closest consanguinity occurs in mating among the chiefs.
There can, therefore, be but little doubt that Man is as capable as some of the animals of thriving on close consanguineous matings, if the streams that become confluent are pure; in fact that when once a human stock has become quite pure close inbreeding is the only means of maintaining it so.
I cannot enter now into the history of the controversy that has raged between the advocates of inbreeding and their opponents. I cannot do more than affirm that none of the ancients had the faintest notion that it could be condemned on biological grounds. Even to-day hardly any two authorities agree as to why inbreeding and incest were condemned among many peoples, at least for the populace, and profound students, like Sir James Frazer, Ernest Crawley, Malinowski and Freud, account for the condemnation, each in his own way.
The moment, of course, that men began to think biologically, it is easy to see why they were prompt in ascribing to divine wisdom a rule which, when broken by badly tainted stocks, appeared to lead to havoc. They reasoned that the havoc was due to the consanguinity, and did not know it was due to the confluence of two tainted streams. And thus, arguing backwards, they justified pseudo-scientifically a rule that had once arisen for no biological reason whatever.
What do inbreeding and outbreeding or cross-breeding respectively mean to the health of a people? It is impossible to separate the psychological from the physiological; but Charles Darwin and many others, who contrive to do so, agree that outbreeding,
Random breeding may destroy mental harmony by combining in one individual emotional reflexes which may be, and often are, conflicting. In this sense, the extreme random breeding of to-day is probably not unconnected with the increase in mental instability and possibly, too, with the increase in insanity and mental defectiveness. In fact, it is probable that to-day not one of us knows the supremely exalted and exhilarating feelings of a being who is thoroughly harmonious and healthy because he is inbred.
The chief effects of miscegenation on the constitution are: firstly, degeneracy, by the reversion that is induced; secondly, dysfunction and disease owing to the production of individuals whose bodies are discordant jumbles of parts from various unlike stocks; and thirdly, increasing morbidity, owing to the fact that there is no canalization of disease, none of health, and deleterious hereditary factors are spread even among sound stocks. Let me take these in their order.
Darwin and others have shown that outbreeding and cross-breeding lead to reversion, or at least to the loss of acquired characteristics, which is the same thing. This has been demonstrated in pigeons, ducks, horses and other animals. Darwin claimed that it was so in Man. It may, as Otto Seeck maintains, have caused the rapid decline of the ancient Greeks and Romans. But I think I have said enough to show that culture and civilization have been almost exclusively the creation of inbred stocks, and therefore to lead to the view that the present age of extremely random breeding must or should be an age of disintegration and decay.
The fact that out- and cross-breeding must lead to ill-health often of the most obscure and undiagnosible kind, by producing discordant individuals or to put it moderately, the fact that miscegenation and random breeding cannot lead to such perfect health as inbreeding and incest has not yet been recognized by medicine, but it soon must be. And here I suggest an enormous amount of fresh light remains to be shed on the etiology of dysfunction.
Any intelligent man facing the facts could have come a priori to the conclusion science is reaching to-day. For, if breeding is the conjunction of two cells and their production of a new individual can be pictured, as I pictured it in the opening, as the intertwining of two sets of wools, then it seems elementary that, if harmony and beauty are to be the result, the wools should come from parents who, apart from sexual differences, have at least the same hereditary equipment. Otherwise something inharmonious must result, something in conflict with itself not only in the morphological sense, but also in instincts and impulses as well; and in a living organism, discord and disparate parts mean ill-health, mental instability, degeneracy.
The evidence confirmatory of these views is very disquieting. For example, Professor Lundborg tells us that in the lower jaw alone two parts can be inherited independently: the angle of the jaw from one parent and the chin from the other. He further declares that there are at least four different parts of the nose that can be inherited independently, and that cross-breeding, or out-breeding, frequently leads to defects in the endocrine balance of the body. Davenport and others have found that the size of the jaw and of the teeth can be independently inherited. But, as Davenport points out, and as was obvious to me twenty years ago, if parts of the jaw and nose can be inherited independently, why not other parts of the body, so that when the parents are unlike, or display any disparity in build, size, or constitution, there may follow all kinds of disparities in the organs a heart too small or too large, a liver out of all proportion to the intestine, and so on. And Davenport, in studying the miscegenation in the North and South of America, says that this is what actually happens. In this population there are tall men with internal organs too small, or circulatory system inadequate, and short men with similar disharmonies.
But these are extreme cases. How much of the subacute and chronic dysfunction we see to-day may not be due to less pronounced disharmonies of this kind, because of our rooted bias in favour of mixed and random breeding?
Although to-day in England and Europe, we may be no longer concerned with actual races, but only with populations, within these populations the utmost confusion of types prevails. There is complete confusion of different sizes, shapes and symmetries. And this "biological proletariat," forbidden incest, and led by magic prejudice to avoid even cousin marriages, cannot help producing generation after generation of people who must inevitably suffer from all the consequences of mental and bodily disharmony. True, Rodenwaldt discovered that there appeared to be a limit to the independent inheritance of psycho-physical characters. He says that he was led to ask the question whether a limit did not exist to the characters which remain correlated in crossing, and to the characters which crossing allotted at random.
But even if, on his authority, we conclude that psycho-physical characters are as a rule handed on in groups which prevent a too frequent occurrence of lethal combinations, on his own showing, an enormous number of psycho-physical characters are inherited independently, and can therefore combine in the child of disparate parents to produce all kinds of mental and physical maladjustments a fact confirmed by Lenz, Lundborg, Fischer, Ruggles Gates and others.
A further reason for condemning out- and cross-breeding is that they disseminate taints; they do not get rid of deleterious factors. Darbishire's experiments have clearly shown that a recessive gene, although it may be associated with its dominant allelomorph for generations, and made inactive, is not influenced by this long association and loses none of its effectiveness. So that random and mixed breeding, in addition to causing psycho-physical disharmony, merely covers up tracks and hands on deleterious factors. In a biological proletariat like the population of modern England, in which most stocks possess the utmost variety of morbid factors, mixed breeding merely conceals taints until the cumulative effect produces total degeneration or lethal disease. As Professor Castle says: "Continuous crossing only tends to hide inherent defects, not to exterminate them, and inbreeding only tends to bring them to the surface, not to create them."
I suggest, therefore, not only that we are in need of a purification of our stocks, but that by prolonging our present method of random and mixed breeding, we are merely living on, and destroying, the health capital still represented by our uncontaminated stocks. While there is yet time we must canalize our healthy streams and canalize our morbid streams. And if we cannot compel the unhealthy not to breed, and cannot guarantee the healthy spouses worthy of them, let us at least encourage both lots to marry their like or else make them do so.
The simplest way to accomplish this end is not to found research councils and then to wait patiently until endless experiments at last provide the criteria for artificial human selection for this process may last so long that at the end of the work we may be too degenerate to wish to avail ourselves of the knowledge derived from it. The simplest way is to break down the barriers now preventing the mating of close relatives, to make it plain to all that these barriers are based on magic, and to spread a new feeling and a new prejudice through the world, which will be
This policy would have the effect of immediately canalizing desirability and undesirability, and would straightway separate the sheep from the goats. True, the deaths from disease and the incidence of insanity in the unsound stocks would be heavy, and it would require the utmost courage to go on. But English people do not usually lack the courage to pursue the things they want. The question is, do they really want health and sanity? Or are they already too debilitated to care?
Between 1925 and 1930, 29,132 people were killed in England and Wales by motor vehicles of all kinds; 5,319 of these were children under ten. In spite of this high and utterly futile death rate from cars, there has been no national protest. Why? Because English people want cars, and are quite prepared to see 30,000 other people sacrificed in five years in order to get what they want. But do English people want health and sanity to the same degree? Are they prepared to sacrifice constructively and usefully more people than they now sacrifice uselessly for the motor car? It may be doubted.
There is no reason, however, to suppose that it would necessarily be an expensive experiment in the healthy stocks. The investigations of G. H. Darwin into the results of first-cousin marriages, even among random-bred and deeply contaminated stock, revealed a surprisingly low incidence of morbidity. In fact, he discovered that the percentage of offspring from cousin marriages to be found in asylums is no greater than the percentage of offspring from non-related persons; and as regards fertility, he found that the balance was slightly in favour of cousin marriages.
Truth to tell, from the point of view of sound eugenic policy, while incestuous mating might immediately be encouraged among tainted or morbid stocks, so that disease and deleterious hereditary factors should become canalized as soon as possible, it would probably be wise to delay for a generation or two an immediate recourse to the closest consanguinity in sound stocks, because of the fear of over-rapidly isolating strains with a too limited set of desirable qualities; and for such stocks it would probably be advisable to be content with using pressure to obtain as many first-, second-, and third-cousin marriages as possible for a little while. But for both schemes, a new and very enlightened attitude will have to be adopted by modern mankind, and much latter-day magic will have to be axed. For it is probable that a scheme of canalization of disease and health would not be practicable without artificial selection accompanied by legalized infanticide for the worst products of the diseased stocks.
Many years ago, long before a number of the facts I have laid before you were known to me, I read a paper before the British Society for the Study of Sex Psychology, in which I answered affirmatively the question: Would a revival of incest not be the salvation of modern man? I was, of course, jeered at. But it may interest you to know the views of an eminent biologist on this very point. Writing in 1927, Professor Crew of Edinburgh said: "Inbreeding is only disastrous if the ingredients of disaster are already in the stock. Inbreeding will purify a stock, but the process may be most expensive. It would seem to be a fact, sufficiently secure for the foundation of sociological practice, that incest between individuals of undoubtedly sound stock is a sound biological proposition."
But it may be a long time before mankind, in these democratic times, so hopelessly under the sway of magic, will see the wisdom of this course.