Creation or Evolution? A Philosophical Inquiry

by George Ticknor Curtis

Let us now advert to another of Mr. Spencer's illustrations of the futility of the "supernatural" and of the rationality of the "natural" interpretation.[82] This illustration is derived from what are called "homologous" organs; and the particular instance selected is the vertebral column.[83] There are creatures, such as snakes, a low order of the vertebrate kingdom, in which the bony axis is divided into segments of about the same dimensions from end to end, for the obvious advantage of flexibility throughout the whole length of the animal. But in most of the higher vertebrata, some parts of this axis are flexible and others are inflexible; and this is especially the case in that part of the vertebral column called the sacrum, which is the fulcrum that has to bear the greatest strain to which the skeleton is exposed, and which is yet made not of one long segment or vertebra, but of several segments "fused together." Mr. Spencer says: "In man there are five of these confluent sacral vertebræ; and in the ostrich tribe they number from seventeen to twenty. Why is this? Why, if the skeleton of each species was separately contrived, was this bony mass made by soldering together a number of vertebræ like those forming the rest of the column, instead of being made out of one single piece? And why, if typical uniformity was to be maintained, does the number of sacral vertebræ vary within the same order of birds? Why, too, should the development of the sacrum be the roundabout process of first forming its separate constituent vertebræ, and then destroying their separativeness? In the embryo of a mammal or bird, the substance of the vertebral column is, at the outset, continuous. The segments that are to become vertebræ, arise gradually in the midst of this originally homogeneous axis. Equally in those parts of the spine which are to remain flexible, and in those which are to grow rigid, these segments are formed, and that part of the spine which is to compose the sacrum, having passed out of its original unity into disunity by separating itself into segments, passes again into unity by the coalescence of these segments. To what end is this construction and reconstruction? If, originally, the spine in vertebrate animals consisted from head to tail of separate movable segments, as it does still in fishes and some reptiles—if, in the evolution of the higher vertebrata, certain of these movable segments were rendered less movable with respect to each other, by the mechanical conditions to which they were exposed, and at length became relatively immovable—it is comprehensible why the sacrum formed out of them should continue ever after to show more or less clearly its originally segmented structure. But on any other hypothesis this segmented structure is inexplicable."

We here see the predominating force of a theory which refuses all possible rationality to any hypothesis but its own. The confident tone with which facts are arrayed and are then pronounced inexplicable upon any other hypothesis than that which the writer asserts, without one scintilla of proof of their tendency to exclude every other supposition, renders the refutation of such reasoning a wearisome task. But there is here one plain and sufficient answer to the whole of the supposed difficulty. The evolution theory, in this particular application of it, is that originally there were vertebrate animals in which the spine consisted of separate movable segments from head to tail, as it does now in fishes and reptiles; but, as the higher vertebrata were evolved out of these lower forms, the movable segments were rendered less movable with respect to each other, and at length in the sacrum the segments became relatively immovable, and yet the originally segmented structure was retained in this part of the column, by force of the propinquity of descent from an antecedent type which had the whole column divided into movable segments. Upon no other hypothesis, it is asserted, is this result explicable.

Mr. Spencer's analysis of the sacrum is somewhat defective. It is, as he says, that part of the vertebrate column which in the higher class of vertebrate animals is, during fœtal life, composed, like all the rest of the column, of distinct vertebræ. These vertebræ, like the others, are flexible in the fœtal stage, but after birth they become coalesced or united into one piece, instead of remaining in separate pieces. Thus far, Mr. Spencer's description is, I am informed by anatomists, correct. But the questions which he propounds as if they were unanswerable upon the assumption that this change is inexplicable upon any other hypothesis than that of the evolution of the higher vertebrata out of the lower vertebrate animals, and that the sacrum, with its continuous piece, has retained the segmented outward form by force of the descent, demand closer consideration. Let us trace the process of formation in the human species, and then see what is the just conclusion to be derived from it. In the embryonic condition, the substance which is to form the vertebral column is continuous. As the fœtus is developed, this substance separates itself into the segments which are called vertebræ, and these segments remain flexible and movable throughout the column. After birth, the five lower segments become united in what is substantially one piece, but of course the marks of the original segments remain. This is what occurs in the origin and growth of the individual. Now, looking back to the period when this species of animal did not exist, and supposing it to have been specially created in the two related forms of male and female, endowed with the same process of procreation and gestation that has been going on ever since there is any recorded or traditionary knowledge of the race, why should not this very growth of the sacrum have been designed, in order to produce, after the birth of the individual, that relative rigidity which would in this part of the vertebral column be useful to an animal destined to an upright posture of the whole skeleton and to the habits and life of a biped? And, if we extend the inquiry to other species, why should we not expect to find, as in the case of an oviparous vertebrate like the ostrich, a repetition of the same general plan of forming the spinal column, for the same ultimate purpose, with such a variation in the number of original segments that are to constitute the sacrum as would be most useful to that bird, thus establishing for the ostrich a sacrum that in a reptile or a fish would not only not be required, but would be a positive incumbrance? Upon the hypothesis of special creations of the different species of vertebrate animals, every one of Mr. Spencer's questions, asked as if they were unanswerable, can receive a satisfactory solution. Thus, he asks, "Why, if the skeleton of each species was separately contrived, was this bony mass [the sacrum] made by soldering together a number of vertebræ like those forming the rest of the column, instead of being made [aboriginally] in one single piece?" The answer is, that in the establishment of the process of gestation and fœtal growth, if a human artificer and designer could have devised the process, he would have selected the very one that now exists, for certain obvious reasons. First, he would have designedly made the process to consist, in the embryo, of a division of the substance which was to form the vertebral column in a continuous and uniform division into segments, because the whole column is to have at first the flexibility that may be derived from such a division. Secondly, when the time was to arrive at which the formation of the sacrum, with its practical continuity of a single piece, was to commence, he would select the number of the lower vertebræ that would make a sacrum most useful to the particular species of animal, and would weld them together so as to give them the relative rigidity and action of a single piece. But as the whole formation is the result of a growth of the sacrum out of a part of the slowly forming column originally divided into vertebræ, the marks of these separate vertebræ would remain distinguishable, while they would cease to have the mechanical action of separate vertebræ.

Another of Mr. Spencer's questions is, "Why, if typical uniformity was to be maintained, does the number of sacral vertebræ vary within the same order of birds?" The answer is the same as that which assigns a reason for all other variations in the skeleton of animals of the same order but of different varieties, namely, the special utility of the variations in the number of sacral vertebræ that would be most useful in that variety. The typical uniformity maintained is a uniformity in the process of growth and formation, down to a point where the variations are to come in which mark one animal from another; and I have more than once had occasion to suggest that the typical uniformity, and its adaptation to the varying requirements of different beings, is the highest kind of moral evidence of the existence, wisdom, and power of a supreme artificer, and that it militates so strongly against the doctrine of evolution that, without more proof than can possibly be claimed for that doctrine, we ought not to yield to it our belief.

The theory that the original condition of all vertebrate animals was that of separate movable segments throughout the spinal column, as it is now in fishes and some reptiles, and that in the evolution of the higher vertebrates out of these lower forms, certain of these movable segments were rendered less movable with respect to each other by the mechanical conditions to which the successive generations were exposed, until at length the sacrum was formed, is undoubtedly a theory that excludes all design of an infinite artificer, and all intention whatever. It is a theory which relegates the most special contrivances and the most exact adaptations to the fortuitous operation of causes that could not have produced the variations of structure and at the same time have preserved the typical uniformity. It is certainly a theory which we should not apply to the works of man, if we were investigating products which seemed to be the result of human ingenuity and skill, but of the origin of which we had no direct evidence. In such a case, we should not shut our eyes to the proofs of intentional variations and adaptation, or, if we did, our speculations would not be likely to command the assent of cultivated and sound reasoners. We may treat the works of Nature by a system of logic that we should not apply to the works of man, but if we do, we shall end in no tenable results. The principal and in fact the only essential distinction to be observed between the works of Nature and the works of man relates to the degree of power, intelligence, and skill in the actor. If we assume, as we must, that in the one case there was an actor, applying will, intelligence, and power to the properties of matter, and molding it into certain products and uses, and that in the other case there was no actor, but that all products and results are but the ungoverned effects of what are called natural laws in contradistinction to all intentional purposes, we must argue upon principles that are logically and diametrically inconsistent in themselves, and at variance with fundamental laws of reasoning.

I will now advert to an omission in Mr. Spencer's analysis of the sacrum, which overlooks one of the strongest proofs of intentional design afforded by that part of the spinal column. We have seen what was its general purpose and growth, and the process of its formation. We have now to note its variations in the male and the female skeleton. In the male, the sacrum, thus formed before birth, after birth answers to and performs its ultimate function of a comparatively rigid and inflexible piece of bone, and it is provided with no other special characteristic. In the female, on the contrary, there is a most remarkable adaptation of this piece to the function of maternity. While all the upper vertebræ of which this piece was originally composed are welded together after birth in the female as in the male, in the female the lowest segment of all remains for a certain time flexible relatively to the upper part of the sacrum, in order to admit of the necessary expansion of the pelvis during the passage of the infant from the womb of the mother. In the normal condition of females of all the vertebrate orders, this flexibility of the lower part of the sacrum continues while the period of possible maternity continues. If in any individual female it happens to be wanting during the period of possible conception, delivery can not take place without danger to the mother or the offspring, or both. Hence, in very bad cases, nature has to be assisted by extraordinary means. But in the normal condition of the female sacrum, this flexibility, so essential in the process of safe delivery, is always found, and its special purpose is known to every anatomist, while it has no existence in the structure of the male. Is this distinction to be accounted for by the same kind of reasoning that undertakes to account for all the other great distinctions between the related forms of male and female, which reproduce their kind by a common process of the sexual union, namely, that this division of male and female came about by a habit that resulted now in the production of a male and now in the production of a female, from tendencies that were ungoverned by any special purpose? Must we not conclude, however inscrutable are the causes that determine the sex of a particular infant, that the sexes themselves were specially ordained? And if they were specially ordained, how are we to account for the special construction and function of each of them, without the interposition of a special design? And when we find a structure in the female obviously designed for a special purpose, and not existing in the male, are we to conclude that some particular race of females, in some remote period of antiquity, among the countless generations of the vertebrata, found that this flexibility of the sacrum would be highly convenient to them, and, having adopted it as a habit, transmitted it, as a specially acquired peculiarity of structure, to their female descendants? This is all very well as a theoretical speculation, but as a speculation it is entirely defective, because it assigns the peculiarity of structure to a cause that could not have produced it. On the other hand, the hypothesis of its special creation assigns it to a cause that could have produced it, and its existence is among the highest of the multitudinous evidences of intentional design and special formation.

Wherein consists the irrationality of the hypothesis that a plan of construction was intentionally, and with supreme skill, framed for very different beings, to answer in each of them a common purpose? The asserted irrational character of this hypothesis consists in nothing but a denial that there was a Creator. It comes down to this, if it comes to anything: because, if we assume that there was a Supreme Being who took any care whatever of the complex and manifold product that we call nature—if we suppose that he ordained anything—we must suppose that his power to construct was boundless, and that a repetition of his plans wherever they would be useful, to answer the beneficent and diversified ends of infinite skill and benevolence, is just as much in accordance with the whole hypothesis of his attributes as it is to suppose that he caused anything whatever to exist. If we deny his existence, if we can not satisfy ourselves of it at all, if we suppose that nothing was ordained, nothing was created, but that all these diversified forms of animal organisms grew out of a protoplasmic substance, and that there was never any absolute commencement of organic life on the globe, or any absolute commencement of anything whatever, it is of course idle to speculate upon the adoption or preservation of patterns, as it is equally idle to pursue the theory of evolution through stages which at last end nowhere whatever.[84]

It may be well to cite Mr. Spencer's final summary of the general truths which he claims to be revealed by morphology, because it will enable the reader to see just where the logical inconsequence of his position occurs: "The general truths of morphology thus coincide in their implications. Unity of type, maintained under extreme dissimilarities of form and mode of life, is explicable as resulting from descent with modification; but is otherwise inexplicable. The likenesses disguised by unlikenesses, which the comparative anatomist discovers between various organs in the same organisms, are worse than meaningless if it be supposed that organisms were severally formed as we now see them; but they fit in quite harmoniously with the belief that each kind of organism is a product of accumulated modifications upon modifications. And the presence, in all kinds of animals and plants, of functionally useless parts corresponding to parts that are functionally useful in allied animals and plants, while it is totally incongruous with the belief in a construction of each organism by miraculous interposition, is just what we are led to expect by the belief that organisms have arisen by progression."[85]

Without expending much criticism upon the phrase "miraculous interposition," as a description of what takes place in special creation, it is sufficient to say that the act of special creation of a distinct organism is to be first viewed by itself, as if it stood alone in nature, and that it is like any other act of causing a new thing to exist which did not exist before. To this idea should be added the fact that in the creation of an animal organism there is involved the direct formation of a peculiar type of animal, with a capacity of producing other individuals of the same type through a process of generation. When, after having attained this conception of the act of special creation, and contemplated a single instance of the supposed exercise of such a power, we extend our inquiries, we find many other instances of the exercise of the same power; and then we observe a certain unity of type in some peculiarity of structure, maintained under extreme dissimilarities of form and mode of life. How, then, is this one similarity of pattern, amid such multiformity in other respects, "worse than meaningless," if we suppose that "organisms were severally framed as we now see them"? The very hypothesis that they were so severally framed carries in itself a meaning which can not be thus summarily ignored; because that hypothesis implies a power in the Creator to do just what we see. You may deny the power; but if you admit the existence of the infinite creating power, you are remitted to the inquiry into its probable methods; and you can no more say that the special creation of distinct organisms, with a certain unity amid a great multiformity, leaves the whole phenomena without a meaning, than you can say that any method which you can suggest is necessarily the only method which will afford a rational meaning in what we see. You must go the length of denying the entire postulate of a Creator, before you can be in a situation to deny the meaning that is involved in the idea of creation; for that idea implies an absolute power to apply a uniform pattern of structure to a whole class of organisms varied in all other respects. The theory that each kind of organism is a product of accumulated modifications upon modifications, without any special interposition to produce the modified and distinct forms, must be maintained on one of two suppositions: either that at some period there was an absolute commencement of organic life in some form, upon this globe, and that then all the other forms which we see were left to be evolved out of that one by the ungoverned accumulation of modifications upon modifications, or else that there was never any absolute commencement of organic life at any time, but that matter, by some peculiar property derived from some source that is not suggested, took on combinations which resulted in some crude form of animated organism, and that then the accumulations of modifications upon modifications followed from some process of generation by which the successive organisms became multiplied and varied. Of the former supposition, I understand Mr. Darwin to have been a representative naturalist. Of the latter, I understand Mr. Spencer to be an advocate. Upon what may be called the Darwinian doctrine, the idea of a Creator, causing to exist at some time some crude form of animal life, is admitted. Upon the Spencerian doctrine, which will be in this respect more closely examined hereafter, I do not see that the idea of a creating power comes in anywhere, either at the commencement of a series of organisms or at any point in that series. But, upon the logical proposition asserted in the passage last above quoted, it is obvious that, unless the idea of a Creator is absolutely denied, the presence of a unity of type amid any amount of dissimilarities of form and mode of life can not be pronounced to be without meaning, because the idea of a Creator implies a power to make that very unity amid the uniformity, which is asserted to be inexplicable without resorting to the theory that it was not made at all, but that it grew out of events over which no superintending or governing power was exercised. Upon this kind of dogmatic assertion there can be no common ground of reasoning.

The assumed incongruity between the facts and the hypothesis of a special creation of each organism is an incongruity that arises out of the assumption that such special creation was an impossibility. If once the idea of an infinite creating faculty is assumed as the basis of the reasoning, all seeming incongruity vanishes, and the probable method of that creating power must be determined by the preponderance of evidence. If the power is denied, we must grope our way through systems which impute everything to the properties of substance, without any suggestion of a source from which those properties were derived, and without anything to guide them but the tendencies implanted in them, we know not how or when, and of the origin of which we have not even a suggestion. Some of the speculations of Greek philosophers adverted to in a previous chapter may serve to show us what comes of the omission to conceive of power as abstracted from substance or its properties. The philosophy which first attained to this conception led the way to that conception of an Infinite Being, without whose existence and attributes all speculation upon the phenomena of nature leads to nothing. A belief in his existence and attributes must undoubtedly be attained by an examination of his works, if we set aside the teachings of revealed religion. But if we can not attain it, we have no better means for believing in the doctrine of evolution than we have for believing in any other method by which the phenomena of nature have become what they are.