When observational science came to exist and the conception of natural law was formed, a certain antagonism between the philosophical and religious conceptions of the world began. Out of this antagonism there came much strife. Religious-minded naturalists endeavored to effect a reconciliation between these diverse views by showing that the order of nature was consistent with the supposition of intelligent control directed to the good of man. Two centuries and more of our modern science bear the marks of this effort towards a reconciliation with religion. Of late these endeavors have fallen into a general and, in good part, deserved disrepute. The disposition of naturalists has been to abandon the problem concerning the ideal or moral control of the universe entirely to the theologians, limiting the work of science to the task of interpreting the fact through the understanding of the conditions which preceded its occurrence. There can be no question that this attitude has been on the whole better for science. In justice to itself, science can only undertake to study the operations of law. When they endeavor to invade the field of the moralist or of the theologian, the votaries of science find that their methods cease to be of any use. They cannot safely trust themselves with considerations which rest upon the intuitional part of man.

The immediate cause which led to the abandonment of the effort to prove the existence of design in the contrivances exhibited by the structure of animals and plants was the sense of the illogical nature of the undertaking. The best-known works of this sort which have been produced are embodied in the Bridgewater Treatises. The several volumes contained in this series of works were designed to illustrate "the power, wisdom, and goodness of God." They all follow substantially the method of the illustrious Paley, and endeavor to show that in the physical and organic world we have the proof of an intelligent creator who adapts the machinery of the world to subserve the best interests. of man. Throughout they embody the notion that contrivance must exist in nature, that the infinite being is in a way cramped by the same conditions as those which limit our own undertakings. The work of these treatises was cleverly done from the point of view taken by the several writers. From that view of creative power, the arguments are fairly well drawn, and for a time the public in general, as well as many scientific men, were captivated by them.

Even before the doctrine of Darwin and others had done much

to undermine the argumentative basis on which these works rest, their method fell into disrepute not only with men concerned with physical science, but also with the abler theologians. The argument rested on the assumption that the divine power was exercised in the reconciliation of difficulties. Such a view is repugnant to any exalted conception of a creator. It rests upon the notion of a finite and not of an infinite power controlling the world. The arguments offended the naturalist for another reason. He had already begun to find many indications of grave imperfections in the organization of animals. Geoffroy St. Hilaire and others had shown that many animals have aborted organs, the relics of previous and lower states of development. It was difficult even for the theologian to reconcile this feature with the hypothesis that these creatures came directly from the creator with the stamp of perfection upon them. When the researches of Lamarck and Darwin forced naturalists to believe that the organic forms now upon the earth were the descendants of those that had been before, and that all organic life had been evolved from the simplest stages of existence, a large part of the arguments derived by the school of Paley ceased to have any place in science. The work of this sort which has recently been done has come to us from the theological side rather than from those who are really informed by the spirit of physical inquiry. Some naturalists have held more or less to this line of argument, but it is clear that on the whole they have been moved rather by their theological impulses than by their motives as investigators of nature.

A somewhat careful study of the problem discussed by the followers of Paley has convinced me that it is not quite reasonable to dismiss the methods of their inquiry in the summary fashion' in which they have been cast aside, that it is worth while to give more discussion to the problem in the light of our better knowledge. In making this inquiry, the results of which I am about to set forth, it may not be amiss to state that I have undertaken this study with every effort to clear my mind of prepossessions and to do the work with no prejudices whatever. I cannot be sure as to the measure of success at which I have arrived in this endeavor, for the evident reason that no one can ascertain the extent to which he has cleared himself from the intellectual past on which all his thought immediately depends.

The first point which the inquirer may be asked to note is, that the hypothesis which holds this universe to be the seat of design is quite as legitimate as the theory that design has no place in the

known world. At present, many of our naturalists, animated by an atheistic spirit, in its way as unscientific as the theistic motive of the older students of nature, are disposed to regard the hypothesis of design as in itself illogical. A fair consideration of the question will probably lead the unbiased student to the conviction that the world may, for the purpose of hypothesis, quite as well be supposed to exhibit design as to be without that feature. Manifestly, the universe either is or is not the place of design. The supposition that any other condition can exist transcends the bounds of our understanding. We are obliged to interpret the visible universe on the basis of our mental organization, and to suppose that there is a third condition in which either design or the lack of it can exist is essentially unreasonable.

The difficulty encountered by the older students of the problem arose from the fact that the contrivances exhibited by organic forms do not necessarily involve design. For instance, in the case of the human hand, it may be shown that it is admirably fitted for the peculiar needs which it serves; but it is equally evident that the hand is descended from the ordinary feet of the lower animals through slight progressive adaptations towards its human form; that probably these several stages in its evolution have been brought about by the necessities of life encountered by the predecessors of man. As soon as it is proved that there is a spontaneous modifying influence at work under the operation of evident natural laws, the argument to support the hypothesis of beneficent control in the universe is fatally weakened. It is true that we can in a fashion strengthen the argument by the supposition that these natural laws are themselves the expression or mode of action of the intelligence, but by this supposition we place the question beyond the range of human understanding, and carry it into a field where intuitions alone can avail us, or, in other words, we take it beyond the realm of physical science and into that of theology.

It is evident that in the present state of biology we cannot safely undertake any arguments founded on advantages of structure to support the hypothesis of intellectual control. Until we have determined in a somewhat accurate way the extent to which the survival of the fittest has served to give shape to the animal and vegetable world, all arguments of the Paleyan sort will be futile. Therefore, in reviewing the field in order to ascertain the possibilities of extending the arguments from design, it seemed to me best to limit the considerations in the main to physical

laws, for in that realm we are clear from the risks of confounding progressive adaptations based upon the inherited experience of organic life with those which are of an intellectual nature, if such there be.

My first object will be to show that organic life is made possible by an extremely fine adjustment of the various terrestrial circumstances which permit of its existence, an adjustment so fine. and depending on so many conditions that we cannot logically suppose that it is the result of chance alone. As will be seen in the development of the reasoning, I endeavor to show that the doctrine of probability makes it appear that the chances of organic life being instituted and maintained on the earth's surface by pure chance is, as the mathematicians phrase it, something like one to infinity."

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The first point to be noted in our inquiry is the narrow range of the temperature conditions which permit the existence of organic life on the earth's surface. For the development of organic conditions it is imperatively necessary that the temperature on the surface of the planet shall not be below the freezing point or above 150° F. At a less temperature than the freezing point all vitalized organisms not endowed with the power of maintaining internal heat by warm blood necessarily die. Above the temperature of 150°, all save the lowest forms, or the eggs of certain inferior organisms, are likewise destroyed. Save for the most inferior creatures in the organic series the possible range of temperature is much less than that which we have noted. If the earth had been peopled only with protozoan life, or that of the lower stages of being, it might have been possible for such beings to have maintained themselves in a range of temperature amounting to as much as 130°; but for all higher forms the range at the place where they live must be less than 100° F. The reason of this narrow limitation in the possible temperatures in which organisms dwell depends in the main upon certain peculiar properties of water. At the freezing point water absolutely ceases to be fit to serve as a vehicle of life, for the reason that it becomes a solid substance. Above the temperature of 150° its unfitness for vital purposes depends upon the fact that albumen and kindred substances change their character and thus become devitalized.

Observing, first, that organic life has been preserved on the surface of this planet in an essentially undisturbed condition for a period of time to be measured by tens of millions if not hundreds of millions of years, let us next notice how delicate is the

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adjustment of the conditions which serve to maintain the earth's surface within this narrow limit of temperature. Within the solar system we have a range of temperature which extends from that of the space which surrounds our planet, which must be considered as several hundred degrees below zero F., to that of the sun's surface, which probably exceeds 100,000° on the same scale. The temperature of the earth's interior is also extremely high, probably amounting to not less than 20,000° or 30,000° F. Thus the organic zone of the earth's surface has been held since the dawn of life in a condition of singularly delicate adjustment as regards heat between the realm of the nether earth and that of the sun, with the intervening space of intense cold separating these two regions of high temperature. There has never been a time since the beginning of this life when at five miles above the earth, even in the tropics, there has not been a cold sufficiently intense, if it came to the surface, to destroy vitality. In no age has the death-giving temperature of the earth's interior ever been more than five miles below the ground.

Thus, considering the distribution of temperature alone, we can see that this film of life has been marvelously held upon the earth; again and again in glacial periods, or in times of great volcanic activity, the endurance of this delicate adjustment would have appeared to the human understanding almost impossible, particularly in glacial periods when the ice sheets made their way from the poles towards the equator, but also in those times when great volcanic outbreaks produced such great lava fields as those which we find in the valley of the Columbia, in the Deccan of India, and elsewhere, it would have appeared to such an observer as if this life could scarcely hold its place amid the forces which contended for its destruction; but always before the fatal moment came there has been a turn in the tide, and these delicate creatures which constitute the organic world have found profit in the peril which environed them. The conditions which seemed to threaten their existence appear to have been really the steps which have led them to higher states of being.

Our sense of the delicacy in the adjustment of the temperature conditions to suit the needs of life upon the earth's surface is much enhanced when we consider certain relations which water bears to organic life. These conditions are somewhat complicated, yet they are of the utmost importance to our inquiry. First we have to note that water is peculiarly conditioned in relation to heat. Above the temperature of about 200° F. in the existing