About the Book

Table of Contents

Part I

Part II

Part III

Part IV

Part V



     

 Part V: Is Man An Animal?

     MAN IS surely the most defenseless of all creatures, unless armed artificially. (93) He appears to have no dependable instincts for self-protection. (94) What natural defenses he can muster from within himself are puny compared with those of animals. And there is no evidence that early man was very different from ourselves, so that we cannot blame this deficiency altogether on a cultural heritage which tends to supply us with substitute defenses. The strength of animals relative to human strength is tremendous. A chimpanzee, for instance, has something like three to five times the strength of man, though considerably less weight (120 lbs.). (95) The fact of man's helplessness in terms of self-defense has been remarked upon by many writers, not a few of whom have seen in it, quite rightly, one of the reasons for his ability to exercise dominion over the rest of Nature. For in lieu of natural equipment he has been granted superior intelligence and learned to arm himself accordingly.
     Years ago Sir William Dawson made this statement: (96)

     It is, in animals below man, a law that the bodily frame is provided with all necessary means of defense and attack, and with all necessary protection against external influences and assailants.
     In a very few cases, we have a partial exception to this. A hermit-crab, for instance, has the hinder part of its body unprotected; and has, instead of armor, the instinct of using the cast-off shells of mollusks; yet even this animal has the usual strong claws of a crustacean for defense in front. There are only a very few animals in which instinct thus takes the place of physical

93. It is possible that honours in this respect may have to go to the koala bear which, I have read, is completely without defenses.
94. Animals appear to know when to stand and fight, and when it is wiser not to do so. This is particularly true of birds, as noted by Alexander F. Skutch, "The Parental Devotion of Birds," Scientific Monthly, April, 1946, p.369.
95. Noted by R. A. Gardner, Science, vol.165, 1969, p.664.
96. Dawson, Sir William, The Story of Earth and Man, Hodder and Stoughton, London,1903, p.365.

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contrivances for defense or attack, and in these we find merely the usual unvarying instincts of the animal. But in man, that which is the rare exception in all other animals becomes the rule. He has no means of escape from danger compared with those enjoyed by other animals, no defensive armor, no effective weapons for attacking other animals.
     These disabilities should make him the most helpless of creatures, especially when taken with his slow growth and long immaturity. His safety and his dominion over other animals are secured by entirely new means, constituting a new departure in creation. Contrivance and inventive power, enabling him to utilize the objects and forces of Nature, replace in him the physical powers bestowed on other animals.
     Obviously, the structure of the human being is related to this, and so related to it as to place man in a different category altogether from any other animal.

     The evidence from antiquity, from the study of fossil man and his cultural remains, indicates that man has always had to depend upon his intellect rather than his physical strength or natural defensive weapons. If man had not fallen, it is my belief that he would not have had to defend himself against other animals at all, but would have achieved dominion over them by a kind of power akin to moral force. Even yet there are among us individuals who seem to have retained something of this power over animals. It would be an interesting question for debate to ask whether many of the defensive instincts of animals would have been necessary if sin had not entered into God's creation, and therefore whether they were conferred upon them by God as soon as man's sin began to disrupt the natural order. Fabre, with the true insight of a devout naturalist, recognized animal instinctual behaviour as "inspired activity." (97)
     But returning to early man, a keen student of civilization, Vere Gordon Childe, wrote:(98)

      Man is now, and was apparently even at his first appearance in the Pleistocene, inadequately adapted for survival in any particular environment. His bodily equipment for coping with any set of conditions is inferior to that of most animals. He has not, and probably never had, a furry coat like the polar bears for keeping in the body's heat under cold conditions. His body is not particularly well adapted for escape, for self-defense, or hunting.
     He is not, for instance, exceptionally fleet of foot, and would be left behind in any race with a hare or an ostrich. He has no protective coloring like the tiger or the snow leopard, nor bodily armor like the tortoise or the crab. He has no wings to offer escape and give him an advantage in spying out and pouncing upon prey. He lacks the beak and talons of the hawk, and its

97. Fabre Henri: quoted by W. R. Thompson in a Convocation Address: "The Work of J. Henri Fabre", in Canadian Entomology, vol.96, nos.1 and 2, 1964, p.70.
98. Childe, Vere Gordon, Man Makes Himself, Thinkers Library, Watts, London, 1948, p.23.

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keenness of vision. For catching his prey and defending himself, his muscular strength, teeth and nails are incomparably inferior. . . .

     As Kipling said, man is indeed "a poor naked frog."
    And yet man has a vast superiority, for all his weakness and in spite of the Fall. He did not entirely lose in Eden the power to obey the command to have dominion over the earth. The processes of civilization are really only exhibitions of this ability expressed in terms of fallen man. During World War II, C. E. M. Joad, a man who thought deeply about the events of his day, wrote a little pamphlet entitled For Civilization. His opening paragraph reads as follows: (99)

     Wherein are to be found the distinctive characteristics of our species? In what, that is to say, do men differ from and excel the beasts? In swiftness or ferocity? The deer and the lion leave us far behind. In size and strength we must give way to the elephant and the whale; sheep are more gentle, nightingales more melodious, tortoises longer-lived, bees more cooperative, beavers more diligent. The ants run a totalitarian State much better than any Fascist.
     The truth is that our bodies are feeble and ill-adapted to survival; they are the prey to innumerable diseases, their enormous complexity means that things can go wrong in a vast number of ways, while so poorly are they equipped against the vagaries of the climate that it is only by clothing ourselves in the skins of other animals that we can survive.

     All these things are true, but not the whole truth, and Dawson, Childe, and Joad from their different points of view would at once acknowledge this. It is true that man is not supplied with natural defenses against potential enemies, but he does have a brain and hands which allow him to design vastly superior weapons for himself. It is true that he is naked, but these same hands and brain allow him to devise clothing which gives him the ability to live where other animals cannot live, except under his protection. He may indeed be slow to move, yet these same hands and brain have made him more mobile and faster than any other creature. And though he may apparently be ill-protected against the vagaries of climate, he is nevertheless, physiologically speaking, quite uniquely equipped to maintain his deep body temperature within remarkably narrow limits over an extraordinary wide range of external conditions of temperature, pressure, and humidity. And as we shall see, in his diet he is further exceptionally fitted to live in any part of the world.
     Many years ago Alexander Macalister, professor of anatomy in the University of Cambridge, wrote a paper entitled "Man, Physiologically Considered," in which he was careful to note that 

99. Joad, C. E. M., For Civilization, Macmillan War Pamphlets, London, 1940, p.3. 

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there are many features of man's anatomy and physiology which contribute to the use he has made of his superior brain: (100)

     While it is thus power of mind, not power of body, which gives to man his supremacy, yet, in all respects, man's bodily organization is fitted to enable him to use to the best advantage his mental endowments.
     If he conceives in his mind the plan of making a weapon, his prehensile hand with its sensitive skin and its independently moving and opposable thumb can fabricate it. His sinuous backbone and completely extensile lower limbs enable him to stand upright with perfect stability, with an ease and perfection competent to no other animal; and thus his forelimbs, relieved from all necessity to act as organs of progression, are perfectly disengaged for work. . . .

     His very weakness has in the providence of God served to enhance man's chief glory, his power to think things through. But his superior mental abilities had to be supported adequately to find expression through the other members of his body, and his body needed to be organized in a number of ways uniquely to make this possible. It was God's intention that he should fill the earth and govern it, and there is little doubt that when this command was given, the climatic conditions on earth were not fundamentally different from what they are today in that while there were zones where the temperature was moderate and laid little stress on the body, there were other zones where man was going to experience considerable heat stress or cold stress. It may be perfectly true that if Paradise had not been lost, the world's climate would have been uniformly temperate, though this would involve tremendous geophysical modifications. But undoubtedly God knew what man would do and that he would face in the end the task of filling a world in which climatic extremes would exist as they do now. He must therefore have been designed, to begin with, with the capability of making the necessary physiological adjustments in order to occupy these challenging zones. No other animal was designed, it seems, for such ubiquitousness.
     Next, let us just consider the nature of territoriality of animals other than man; then, the significance of man's uniformity of physical type in spite of his wide dispersal and often long isolation; and finally, all too briefly, the complex mechanisms by which man maintains his deep body temperature at the optimum level to allow the exercise of his full potential as a thinking creature within an exceptional range of external conditions. This study will serve to

100. Macalister, Alexander, Man Physiologically Considered, vol.7, no.39 in Present Day Tracts, Religious Tract Society, London, 1886, pp.6, 7.

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demonstrate that this mechanism in man is in certain fundamental respects quite different from the mechanism which serves somewhat the same purpose in animals, and this will underscore at the same time the fact that it is easy for the in-expert to suppose that because the mechanisms look alike they are in fact the same.

     First, consider the extent of animal territories. Every increase in our knowledge of this subject only tends to confirm that all animals have limited territories, which they mark out rather specifically. Often more than one species will occupy a single area, but each species marks out its territorial boundaries in defiance of other members of its own species. In the case of social animals, the territory owned by the individual may be quite small. Birds, especially sea birds, may claim only space sufficient to land upon and lay their eggs. But other animals, like some of the large cats, may dominate territories covering a number of square miles. Just as an illustration of the kind of spread involved, the weasel may claim from two to nine acres, a male stoat up to eighty-five acres, martens about one square mile, a waterbuck anywhere from forty to five-hundred acres, some bears, ten square miles or more, and a pride of fifteen lions, thirty or more square miles. (10l) The territory of animals which migrate should not strictly include their corridors of migration which they merely pass through, but must be limited to their range of wintering or summering. The primates nearest in form to man claim territorial rights over far less territory, the proportion working out to about two and one-half chimpanzees per square mile, for example. (102) The Sifaka monkeys in Madagascar occupy about three acres each.
     Social animals that live in colonies seem to crowd their environment, but apparently, except under stress, they do not actually compete severely for the food supply. Herds of animals may live with herds of another species, serving as sentinels for one another but not competing for the available food because their diets are different. I think it is amusing that evolutionists who believe that Nature has advanced itself by the very fact of competition are also able to turn around and show that evolution has often had the reverse effect, i.e., limiting competition. So we have a situation in which competition leads to evolution upwards while evolution tends towards the elimination of competition. Thus a magnificent volume, The Living World  

101 The Living World of Animals, edited by L. Harrison Matthews, Readers Digest Publication, London, 1970, pp.56, 58, 59, 101, 106.
102. Ibid.: Chimpanzees, p.198; Sifaka monkeys. p.215.

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Of Animals, under the editorship of L. H. Matthews and others, has this enlightening paragraph: (103)

     This concentration of animals (in Africa) does not lead to the severe competition between species for food that might be expected, because each has his own preferences even when several different species graze upon the same plant. Red Oat grass, for instance, is eaten by the zebra, the wildebeest, and the topi, but each feeds upon it at a different stage of the plant's growth. This limited competition, the result of evolution [my emphasis], has permitted a great variety of animals to fit into the environment; every species has its niche, from the smallest insect to the elephant.

     Not only are animal territories rather precisely defined, but the geographic distribution of species tends to be equally well defined, except where man has interfered and taken domesticated animals with him. Of the primates, the gorilla is confined to a small tract of West Africa about the size of France. The chimpanzee, although ranging over a larger district of Equatorial Africa, still does not extend beyond the region limited by the parallels 12 degrees north and south latitudes, and in this belt is only found between the sea coast on the west and the meridian of Lake Tanganyika on the east. The orangutan is limited to the islands of Sumatra and Borneo. (l04)
     Washburn and Lancaster, in a paper on the evolution of hunting, remark upon the difference between the territory occupied by men who hunt as opposed to animals which hunt: (105)

     Social groups of non-human primates occupy exceedingly small areas, and the vast majority of animals probably spend their entire lives within less than 4 or 5 square miles. Even though they have excellent vision and can see for many miles, especially from the tops of trees, they make no effort to explore more than a tiny fraction of the area they see.
     Even for gorillas the range is only about 15 square miles, and it is of the same order of magnitude for savanna baboons; they refuse to be driven beyond the end of their range and double back. The known area is a psychological reality, clear in the minds of the animals. Only a small part of even this limited range is used, and exploration is confined to the canopy, lower branches, and bushes, or ground, depending on the biology of the particular species. . . .
     In marked contrast, human hunters are familiar with very large areas. In (one) area studied . . . eleven water holes and several hundred square miles supported a smaller number of Bushmen than the number of baboons supported by a single water hole and a few square miles in the Amboseli Reserve in Kenya. The most minor hunting expedition covers an area

103 Ibid., p.96.
104. Macalister, Alexander, Man Physiologically Considered, vol.7, no.39, Present Day Tracts, Religious Tract Society of London, 1886, p.5.
105. Washburn, S. L., and Lancaster, C. S., "The Evolution of Hunting," in Human Evolution, edited by N. Korn and F. Thompson, Holt, Rinehart & Winston, New York, 1967, p.73.

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larger than most non-human primates would cover in a lifetime. Interest in a large area is human.

     It is not unusual for a single Eskimo family to occupy for hunting purposes a territory stretching for 200 to 300 miles. Moreover, unlike any other species, man seems by nature a wanderer and an explorer, to whom no part of the globe does not have an appeal in one way or another. Man is truly ubiquitous.

     For all his ubiquity man has not, even in those earlier periods of history in which population was thin and tribes were often isolated for centuries, developed varieties of the species Homo sapiens to anything like the extent that animals have. It is true that in one area of the world, Africa, we do have Pygmies whose average height is perhaps four feet six inches, and Nilotic Negroes whose average height may be around seven feet, but in terms of body mass the difference between the Nilotic Negroes and the Congo Pygmy is far less than, for example, the difference between the St. Bernard and the Chihuahua. Moreover, this apparent limitation in terms of variability within the family of man has made it possible for all races to interbreed freely. In the case of the St. Bernard and the Chihuahua, for example, interbreeding is not successful for physical reasons unless artificial means are used. And if the mother is the Chihuahua, she apparently cannot bear her pup sired by a St. Bernard because of its size at full term.
     Within the animal kingdom other factors may result in psychological blocks to successful mating -- the time of heat of varieties of a single species too-long separated may not be in register; sometimes the block is apparently due to unacceptable body odour caused by a difference in diet. The inflexibility of the period of heat among species, an inflexibility which is governed by their need to bear their young at an appropriate time in the year, is said by some authorities to be responsible for the extinction of at least some species in early Pleistocene times when it is held that great climatic changes were taking place. (106)
     Experience shows, by contrast, that none of these barriers exist between members of the human species, though they may be brought together from the ends of the world for the first time in human history. Mankind as a species has not a restricted "season of 

106. Slaughter, W. H., "Animal Ranges as a Clue to Late-Pleistocene Extinctions," in Pleistocene Extinctions, vol.6 of the Proceedings of the 7th Congress of the International Association for Quaternary Research, edited by P. S. Martin and H. E. Wright, Yale University Press, 1967, p.155. 

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heat," such as characterizes all other species. And this fact has tremendous importance, as we shall see in the next chapter. The potential for interbreeding successfully seems to me to indicate that, unlike other animals, man was uniquely designed from the beginning to be able to go anywhere in the world without becoming a genetic isolate.
     Although I cannot find myself in agreement with Teilhard de Chardin, he is certainly correct in underscoring the importance of this fact for man: (107)

     By climatic and geographical influences, varieties and races (of animals) come into existence. Somatically speaking, the fanning out (of man) is present continually in formation and perfectly recognizable. Yet the remarkable thing is that its divergent branches no longer succeed in separating.
     Under conditions of distribution which in any other initial phylum would long ago have led to the breakup into different species, the human vertical as it spreads out remains entire, like a gigantic leaf whose veins, how ever distinct, remain always joined in a common tissue. With man we find independent (interfertility) on every level. . . .
     Zoologically speaking, mankind offers us the unique spectacle of a species capable of achieving something in which all previous species had failed. It has succeeded, not only in becoming cosmopolitan, but in stretching a single organized membrane over the earth without breaking it.

     It is clear, then, in a way which has never been demonstrated for animals, that every variety of man is "made of one" (Acts 17:26, where the word "blood" is probably not part of the original text). And this true unity of such a far-flung race guarantees that throughout history One Man could always be recognized as a true representative of all men, without exception.
     Another notable circumstance with respect to animal populations is the interesting fact that according to our present understanding, animal species remain remarkably stable in terms of the number of individuals constituting each particular species. Were it not so, of course, their territories would have to increase or they would have to become progressively more crowded. Darwin saw that all organisms possess the potentiality for increase, a potentiality not merely for arithmetical multiplication but geometric. It was this belief that led him to assume that Malthus' essay on human population growth must also apply to animals. He therefore postulated an unending

107. Teilhard de Chardin, Pierre, The Phenomenon of Man, Collins, London, 1955, p.241. A more "orthodox" authority, G. G. Simpson, has remarked upon the same circumstance: "Regardless of the diversity of races, it is obvious that all men resemble one another much more than any of them differ from each other. They all share the basic quality, anatomical, physiological and psychological, that make us human, Homo sapiens, and no other species that is or ever was" (Biology and Man, Harcourt, Brace & World, New York, 1969, p.87).

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struggle to survive, with the triumph of the fittest. We know now that this was an entirely erroneous extrapolation from human to animal population growth. Sir Julian Huxley himself underscored the fact that for various reasons this population growth does not materialize, and so he observed, "In spite of the tendency to progressive increase, the numbers of a given species actually remain more or less constant." Subsequently, he wrote: (108)

     With our much greater knowledge of ecology, we know today that many species undergo cyclical and often remarkably regular fluctuations, frequently of very large extent in their numbers.

     At this point, he referred to the work of Charles Elton, and although I do not have the work he refers to, I do have a similar work by that author in which he underscored this interesting finding, and after giving some specific illustrations, concluded: (109)

     All this goes to support the idea that there is some important principle involved in the stability of the total number of species in an animal community.

Elton was speaking in this case not of the number of individuals in a species but the number of species in a given area. This is a fact which has been recognized for a long while: namely, that when any particular species dies out, some other species will move in to fill the ecological niche which has thus become vacant. But they do not over-populate it. So the web of life is preserved intact, and the total number of animals as a consequence remains remarkably constant. The pattern of human population growth is quite otherwise. Were it not so, man would never finally "fill the earth." But did those constraints against anima/ population growth not exist, it could very well be that the animals, rather than man, would have usurped his dominion long before this.
     In the meantime, evidence has recently come to light that, again, unlike human beings, animals are somehow able to control their own numbers, not by killing off unwanted children as it were, but by producing fewer offspring. This has become apparent, for example of the elephant population in the Murchison Falls area of Western Uganda in Africa. (1l0) Where one section of this particular population has had its territory reduced by the extension of farming, 

108. Huxley, Sir Julian, Evolution: the Modern Synthesis, Harper, New York, 1942, p.15.
109 Elton, Charles, The Ecology of Animals, Methuen, London, 1950, p.20. See also his "Animal Numbers and Adaptation" in Evolution: Essays on Aaspects of evolutionary Biology, edited by Sir Gavin de Beer, Oxford University Press, 1938, pp.127�137.
110. Animal population stability: Robert Ardrey, in a series of two articles on the subject in The Globe and Mail, Toronto, September 30 and October 1, 1971. 

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---

the elephant population has somehow diminished by a change in the birth rate. The normal spacing for calves is four years; in this potentially over-crowded area it has risen to nine years. No one knows the mechanics of this, though it has recently been recognized that the same thing may happen in other parts of the world. In an English woodland, if the number of great-tits doubles, in the next season the egg clutch size will be reduced by two. In an Iowa marshland, if muskrat numbers rise too high, then the mother muskrat produces fewer embryos or re-absorbs them.

     Another factor which contributes to man's unique ubiquity is his willingness and ability to accept a vegetarian or meat diet with equal ease. There are millions of people who for centuries have been to all intents and purposes vegetarian, such as those in the Far East who depend upon cereals (rice, etc.). By contrast, there have been branches of the human race, such as the Eskimo people, who were not completely but almost entirely meat eaters. At certain seasons of the year they probably had some fruits in the form of wild berries. The human body, therefore, can be nourished equally well by either form of diet.
     By contrast, as Loren C. Eiseley says, "All of the existing great apes are essentially vegetarian, and indeed the arboreal bracchiators have no other consistent source of food." (111) Whether these creatures could successfully adopt a carnivorous diet without completely changing their character, or at least becoming no longer interfertile with members of their own species who remain vegetarian, it is difficult to say. It is known that in at least one branch of the primates, a number of animals have changed their diet from a herbivorous to a carnivorous one due to man's disturbance of their natural environment. Eugene Marais pointed out that up until about 1860 the wild baboons in Africa fed on insects and roots. (112) In a manner of speaking, they were therefore already omnivorous, though insects as part of a diet do not usually qualify the eater as a carnivore. But the drying up of the continent due to man's bad farming management, forced these animals to look for liquid to drink from new sources, and they started killing goats just to suck the milk from their udders. In time they began attacking all kinds of domestic animals and eating them for food.

111. Eiseley, Loren C., "Fossil Man and Human Evolution," in Current Anthropology, edited by W. L. Thomas, University of Chicago Press, 1956 , p.73.
112 Marais, Eugene, My Friends, the Baboons, Methuen, New York, 1939, p.1.

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     This is an exceptional circumstance, not a natural one. And the fact remains that virtually no other animal bearing some similarity to man is equally capable of living on either a vegetarian or a meat diet. This is of great importance to man, for there are areas of the world where vegetables are simply not available (for example, desert areas and the high Arctic) unless they are imported. The settlement by man of such areas would therefore have been altogether impossible unless he had been omnivorous by nature. Man's constitution is therefore such that in this also he is uniquely equipped to fill the earth and subdue it in a way that no other creature is.
     We come, then, to one further aspect of human constitution which is easily overlooked but is of equally profound significance for man in the light of his original commission. This has to do with the means by which he maintains his body temperature.

     Although all animals, whether cold-blooded or warm-blooded, must have some temperature regulation in order to sustain life, there are ascending degrees of regulation as we move up the scale of complexity in animal form. The cold-blooded animals are not strictly cold-blooded. They are so constituted that within certain limits their body temperature floats with the environmental conditions, and the amount of energy they have fluctuates accordingly. They are sluggish and virtually defenseless when the environmental temperature falls below a certain level, because energy is derived in the animal body by the "burning" of food stuffs and this burning process becomes very inefficient at low temperatures. Obviously, such creatures must be able to prevent a fall below a certain point, otherwise they would lack energy even for digestion and other vital processes. They can, however, sustain a fall in deep body temperature far below that of warm-blooded animals. This is an advantage to them in terms of survival where they are not in danger of attack from other animals, but it severely limits their potential for accomplishment. The next level seems to be found in those animals which, although they are able to maintain their body temperature quite close to that of man, nevertheless have the ability to allow their temperature to fall everywhere in the body except in certain vital organs. There are animals which can hibernate. They reduce the demand of their body for energy to an absolute minimum for long periods of time and pass into a state of dormancy. But when the external environmental temperature rises above a certain point some mechanism awakens them and they become as active as any  

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other warm-blooded animal, thereafter maintaining their body temperature throughout the season of warm weather as other warm-blooded animals do throughout the year.
     There is a third class of animals, among which man seems to be but one among many, which have an in-built thermoregulatory system. Except under very extraordinary circumstances and with extreme rarity, this system maintains the body temperature as a whole within a degree or two of some norm � in mammals around 98 degrees F. and in birds a few degrees higher.
     I have emphasized the word seems in connection with man, because in point of fact his thermoregulatory system is quite unique and involves several mechanisms which are not found in other animals in spite of appearances to the contrary. (113) Briefly, the system works somewhat as follows: When the human body is threatened with a fall in temperature, the first line of defense is what is called peripheral vasoconstriction, in which the circulating blood is prevented from flowing through the tiny capillaries immediately at the skin surface and is short-circuited back into the venous return flow system through special channels (anastomoses). As a result, it does not reach the surface where it would be chilled by radiation loss and by conduction to the cold surface. The effect is that the skin turns white. At the same time, this white skin acquires approximately the insulating value of cork by the reduction of its fluid content and correspondingly lowered conductivity. (1l4)
     If this first line of defense proves insufficient, the body initiates a second defense mechanism, namely, the tightening up of skeletal muscles, especially in the limbs. This muscle tension generates heat metabolically and can actually double the resting metabolism of the body. It also, of course, accumulates waste from the breakdown products of the metabolism and results in the feeling of stiffness and ache that is experienced after exposure to the cold for a sufficient length of time. Muscle tension is maintained by the asynchronous firing of nerve impulses to the muscles.
     If this second line of defense mechanism still proves inadequate, then the asynchronous firing of nerve impulses is synchronized and the muscles begin to contract in unison. We experience this as shivering. And if shivering is allowed (one should not try to suppress

113. As Douglas J. H. K. Lee put it, "Man is supreme as a Homeotherm." See "Heat and Cold," in Annual Review of Physiology. vol.10. 1948, p.368.
114. E. F. DuBois gives the specific conductivity of epidermis, subcutaneous fat, and muscle tissue when not bathed in sweat water and in a condition of vasoconstriction as 0.00047 to 0.00050 gm. cal/sec./cm2/cm., compared with the specific conductivity of cork, which is 0.0007.

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it), metabolic heat generated within the body may be increased threefold.
     We therefore have a dual mechanism for maintaining the body temperature against a fall which involves muscular activity and a shift in circulation. Animals shiver, but it does not appear that they have the human defense of a closed-down peripheral circulation to reinforce its effect. It should be understood that the circulation of the blood is of crucial importance in the matter of temperature regulation, acting rather like a hot or cold water system in a house, the fluid itself forming the heat reservoir and by its circulation providing a highly efficient heat exchanger.
     When the body is threatened with a temperature rise, a threat which incidentally is far more dangerous to man, a somewhat different mechanism is set in motion. The first line of defense is, again, a change in the circulation of the blood at the periphery. In this instance, miles of tiny capillaries are opened up and the blood floods through them very close to the skin surface. This is known as vasodilatation, and the visual effect is that the skin reddens. It happens in the cheeks very rapidly under emotional stress (i.e., blushing). Certain drugs like alcohol will also produce the same effect of reddening in the face and neck. A rise in body temperature due to an increase in environmental temperature is immediately counteracted by this peripheral vasodilatation. The mechanical effect is now to allow the blood to cool at the surface. Deep body heat is thereby transported and eliminated by radiation and conduction from the skin surface.
     If this should prove insufficient, a second line of defense is at once initiated, a line of defense which, contrary to popular opinion, is believed to be unique in man. This is technically known as thermogenic sweating. The thermostat in the body appears to be situated in the hypothalamus which is bathed in blood and responds to minute changes in blood temperature. (1l5) A rise of 0.01 degrees C in hypothalamic temperature is sufficient to initiate sweating when the set point has been reached. (1l6) During sweating, the body surface becomes bathed in a watery fluid expressed to the skin surface via some two million sweat glands, where it evaporates. The evaporation of water occurs only where the ambient air is able to absorb the

115. Custance, Arthur C., "The Existence, Nature, and Behaviour of the Set-point in the Human Thermostat," DREO Report 622, Defence Research Board., Ottawa, 1970, 36 pages.
116. For a fuller discussion: T. H. Benzinger, "The Human Thermostat," in Temperature: Its Measurement and Control in Science and Industry, vol.3, no.3, Reinhold, New York, 1963, pp.637-665.  

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water vapour. When this can be 100 percent effective, the amount of heat removed from the body under certain circumstances can be extraordinary since the body has the ability to sweat copiously. In our own experiments, we have not infrequently observed that men can lose five or six pounds (up to three liters) of body water by this means within a single hour. This is under extreme conditions of heat stress, but it can be sustained for a surprising length of time without ill effect provided that the water is replaced. Very little rise in body temperature will occur under these conditions. The moment sweating is prevented by the use of drugs which suppress it (117) or is made valueless because the water expressed to the skin surface cannot evaporate, deep body temperature will begin to rise precipitously � and with fatal results.
     These two mechanisms of handling heat and cold contribute fundamentally to man's ability to live in the Arctic or in the tropics with comparative ease. On the whole, he sustains the thermal stress better when it is negative, i.e., when there is a threat to the reduction of his body temperature. (1l8) He is better in the cold than in the heat, though not always as comfortable. Being such a creature as he is, man prefers to feel warm. But in point of fact, he is in much greater danger from heat and is likely to be much less energetic both physically and intellectually. He therefore tends to over-compensate against the cold by heating his buildings more than he really needs to do, thus reducing his acclimatization to the cold, a circumstance which only increases his sensitivity to it and his distaste for it. Nevertheless, he is uniquely equipped to maintain the temperature of his vital organs, especially his brain, at an optimum level for fruitful and energetic employment.
     His body is exceptional in this regard. Many animals have sweat glands, some of them in the mouth (like dogs), some of them over the whole body surface (like horses), but in Nature no animal has the ability to prevent a temperature rise in times of heat stress which is comparable to man's. In spite of appearances to the contrary, the sweating of horses is initiated for quite other reasons and serves a cooling function only by accident and with nothing like the efficiency that it serves in man. (1l9) Physiologically, the sweating of

117. Custance, Arthur C., "A Method of Measuring the Effect of Drugs on Sweating as a Function of Time," Canadian Medical Association Journal, vol.95, 1966, p.871-874.
118. Custance, Arthur C., "Stress-Strain Relationship of Man in the Heat," Medical Services Journal Canada, vol.23, no.5, 1967, p.721-726.
119. Sweating of animals: see, for example with respect to horses, Stephen Rothman, Physiology and Biochemistry of the Skin, University of Chicago Press, 1955, p.166. Also, H. M. Frankel et al., "Effects of Type of Restraint upon Heat Tolerance in Monkeys," Proceedings of Experimental Biology and Medicine, vol.97, 1957, p.339-341; C. H. Wyndham, "Role of Skin and Core Temperatures in Man's Temperature Regulation," Journal of Applied Physiology, vol.20, 1965, p.36; J. D. Hardy, "Summary Review of Heat Loss and Heat Production in Physiological Temperature Regulation," NADC-MA-5413, U. S. Naval Air Development Center, Johnsville, Pa., October 1954, p.12; and "Control of Heat Loss and Heat Reduction in Physiological Temperature Regulation," Harvey Lectures Series, 49, Academic Press, New York, 1953-54, pp.247-252; Sir Charles Lovett Evans, "The Autonomic Nervous System" British Medical Bulletin, vol.13, no.3, 1957, p.154,199.

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horses is not thermogenic at all, that is to say, it is not initiated by a rise in temperature in the animal but is due to the increase in adrenaline in the animal's bloodstream as a result of violent exercise. In Nature the animal would not sweat, because it would not exercise itself as man exercises it. In addition to this, the circulatory adjustments of which the human body is capable in response to temperature fluctuation is not known in any other animal. (120) Thus man has clearly been built to maintain his body temperature against challenges with which no other species is likely to be faced in Nature. These circulatory adjustments involve a tremendously complex neuromuscular activity for which the human body seems to be expressly designed, and one can only suppose, therefore, that God knew what would happen to man after he fell and made provision beforehand for just such a contingency, a provision which He did not have to make when He designed all the other creatures which were to share his world but not share his ubiquity.

     The whole body of man has, therefore, clearly been designed to support and enhance the uniqueness of his mind. Mind, tongue, and hand have somehow been structured in a very remarkable way to give coordinated expression to the sum total of human potential to the power of reflection, of communication, and of creation; in fact; at one and the same time, of having dominion over the rest of God's creation and yet of worshipping the Creator. But it is not merely the structure of his brain and the anatomy of his body which have made these things possible. Man's uniqueness goes deeper than this. In some not yet clearly understood way, his whole physiological organization and the very special quality of his spirit have together played a part in leading inevitably to the kind of culture that he creates as a framework for his own self-expression and restraints, and -- in the final analysis -- the kind of redemption he needs and is capable of apprehending by faith. We next look first at the kind of culture he has

120. Circulatory adjustment in man: see on this, for example, R. H. Fox and O. G. Edholm in "Nervous Control of Cutaneous Circulation," British Medical Bulletin, vol.19, no.2, 1963, p.110-114.  

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created and why it has almost inevitably taken the form it has. Then we look at his combined need for and capacity for salvation, a truly unique need and capacity which apparently has never applied to any other of God's creatures, whether angel or animal.

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