The parallelism of these conclusions of careful inductive inquiry into the structure of the earth's crust, with the results which we have already obtained from revelation, may be summed up under the following heads:
1. Scripture and Science both testify to the great fact that there was a beginning—a time when none of all the parts of the fabric of the universe existed; when the Self-Existent was the sole occupant of space. The Scriptures announce in plain terms this great truth, and thereby rise at once high above atheism, pantheism, and materialism, and lay a broad and sure foundation for a pure and spiritual theology. Had the pen of inspiration written but the words, "In the beginning God created the heavens and the earth," and added no more, these words alone would have borne the impress of their heavenly birth, and would, if received in faith, have done much for the progress of the human mind. These words contain a negation of hero-worship, star-worship, animal-worship, and every other form of idolatry. They still more emphatically deny atheism and materialism, and point upward from nature to its spiritual Creator—the One, the Triune, the Eternal, the Self-Existent, the All-Pervading, the Almighty. They call upon us, as with a voice of thunder, to bow down before that Awful Being of whom it can be said that he created the heavens and the earth. They thus embody the whole essence of natural theology, and most appropriately stand at the entrance of Holy Scripture, referring us to the works which men behold, as the visible manifestation of the attributes of the Being whose spiritual nature is unveiled in revelation. Scripture thus begins with the announcement of a great ultimate fact, to which science conducts us with but slow and timid steps. Yet science, and especially geological science, can bear witness to this great truth. The materialist, reasoning on the fancied stability of natural things, and their inscription within invariable laws, concludes that matter must be eternal. No, replies the geologist, certainly not in its present form. This is but of recent origin, and was preceded by other arrangements. Every existing species can be traced back to a time when it was not; so can the existing continents, mountains, and seas. Under our processes of investigation the present melts away like a dream, and we are landed on the shores of past and unknown worlds. But I read, says the objector, that you can see "no evidence of a beginning, no prospect of an end." It is true, answers geology; but, in so saying, it is not intended that the present state of things had not an ascertained beginning, but that there has been a great and, so far as we know, unlimited series of changes carried on under the guidance of intelligence. These changes we have traced back very far, without being able to say that we have reached the first. We can trace back man and his contemporaries to their origin, and we can reach the points at which still older dynasties of life began to exist. Knowing, then, that all these had a beginning, we infer that if others preceded them they also had a beginning. But, says another objector, is not the present the child of the past? Are not all the creatures that inhabit the earth the lineal descendants of creatures of past periods, or may not the whole be parts of one continual succession, under the operation of an eternal law of development? No, answers geology, species are immutable, except within narrow limits, and do not pass into each other, in tracing them toward their origin. On the contrary, they appear at once in their most perfect state, and continue unchanged till they are forced off the stage of existence to give place to other creatures. The origin of species is a mystery, and belongs to no natural law that has yet been established. Thus, then, stands the case at present. Scripture asserts a beginning and a creation. Science admits these, as far as the objects with which it is conversant extend, and the notions of eternal succession and spontaneous development, discountenanced both by theology and science, are obliged to take refuge in those misty regions where modern philosophical skepticism consorts with the shades of departed heathenism. [148]
2. Both records exhibit the progressive character of creation, and in much the same aspect. The Almighty might have called into existence, by one single momentary act, a world complete in all its parts. From both Scripture and geology we know that he has not done so—why we need not inquire, though we can see that the process employed was that best adapted to show forth the variety of his resources and the infinitely varied elements that enter into the perfect whole.
The Scripture history may be viewed as dividing the progress of the creation into two great periods, the later of which only is embraced in the geological record. The first commences with the original chaos, and reaches to the completion of inorganic nature on the fourth day. Had we any geological records of the first of these periods, we should perceive the evidences of slow mutations, tending to the sorting and arrangement of the materials of the earth, and to produce distinct light and darkness, sea and land, atmosphere and cloud, out of what was originally a mixture of the whole. We should also, according to the Scriptural record, find this period interlocking with the next, by the intervention of a great vegetable creation, before the final adjustment of the earth's relations to the other bodies of our system. The second period is that of the creative development of animal life. From both records we learn that various ranks or gradations existed from the first introduction of animals; but that on the earlier stages only certain of the lower forms of animals were present; that these soon attained their highest point, and then gradually, on each succeeding platform, the variety of nature in its higher—the vertebrate—form increased, and the upper margin of animal life attained a more and more elevated point, culminating at length in man; while certain of the older forms were dropped, as no longer required.
In the oldest fossiliferous rocks next to the Eozoic, which so far have afforded only Protozoa—e. g., the Cambrian and Lower Silurian—we find the mollusca represented mainly by their highest and lowest classes, by allies of the cuttle-fish and nautilus, and by the lowest bivalve shell-fishes. The Articulata are represented by the highest marine class—the crustaceans—and by the lowest—the worms, which have left their marks on some of the lowest fossiliferous beds. The Radiata, in like manner, are represented by species of their highest class—the starfishes, etc.—and by some of their simpler polyp forms. At the very beginning, then, of the fossiliferous series, the three lower sub-kingdoms exhibit species of their most elevated aquatic classes, though not of the very highest orders in those classes. The vertebrated sub-kingdom has, as far as yet known, no representative in these lowest beds. In the Upper Silurian series, however, we find remains of fishes; and in the succeeding Devonian and carboniferous rocks the fishes rise to the highest structures of their class; and we find several species of reptiles, representing the next of the vertebrated classes in ascending order. Here a very remarkable fact meets us. Before the close of the Palæozoic period the three lower sub-kingdoms and the fishes had already attained the highest perfection of which their types are capable. Multitudes of new species and genera were added subsequently, but none of them rising higher in the scale of organization than those which occur in the Palæozoic rocks. Thenceforth the progressive improvement of the animal kingdom consisted in the addition, first of the reptile, which attained its highest perfection and importance in the Mesozoic period, and then of the bird and mammal, which did not attain their highest forms till the Modern period. This geological order of animal life, it is scarcely necessary to add, agrees perfectly with that sketched by Moses, in which the lower types are completed at once, and the progress is wholly in the higher.
In the inspired narrative we have already noticed some peculiarities, as, for instance, the early appearance of a highly developed flora, and the special mention of great reptiles in the work of the fifth day, which correspond with the significant fact that high types of structure appeared at the very introduction of each new group of organized beings—a fact which, more than any other in geology, shows that, in the organic department, elevation has always been a strictly creative work, and that there is in the constitution of animal species no innate tendency to elevation, but that on the contrary we should rather suspect a tendency to degeneracy and ultimate disappearance, requiring that the fiat of the Creator should after a time go out again to "renew the face of the earth." In the natural as in the moral world, the only law of progress is the will and the power of God. In one sense, however, progress in the organic world has been dependent on, though not caused by, progress in the inorganic. We see in geology many grounds for believing that each new tribe of animals or plants was introduced just as the earth became fitted for it; and even in the present world we see that regions composed of the more ancient rocks, and not modified by subsequent disturbances, present few of the means of support for man and the higher animals; while those districts in which various revolutions of the earth have accumulated fertile soils or deposited useful minerals are the chief seats of civilization and population. In like manner we know that those regions which the Bible informs us were the cradle of the human race and the seats of the oldest nations are geologically among the most recent parts of the existing continents, and were no doubt selected by the Creator partly on that account for the birthplace of man. We thus find that the Bible and the geologists are agreed not only as to the fact and order of progress, but also as to its manner and use.
3. Both records agree in affirming that since the beginning there has been but one great system of nature. We can imagine it to have been otherwise. Our existing nature might have been preceded by a state of things having no connection with it. The arrangements of the earth's surface might have been altogether different; races of creatures might have existed having no affinity with or resemblance to those of the present world, and we might have been able to trace no present beneficial consequences as flowing from these past states of our planet. Had geology made such revelations as these, the consequences in relation to natural theology and the credibility of Scripture would have been momentous. The Mosaic narrative could scarcely, in that case, have been interpreted in such a manner as to accord with geological conclusions. The questions would have arisen—Are there more creative Powers than one? If one, is He an imperfect or capricious being who changes his plans of operation? The divine authority of the Scriptures, as well as the unity and perfections of God, might thus have been involved in serious doubts. Happily for us, there is nothing of this kind in the geological history of the earth; as there is manifestly nothing of it in that which is revealed in Scripture.
In the Scripture narrative each act of creation prepares for the others, and in its consequences extends to them all. The inspired writer announces the introduction of each new part of creation, and then leaves it without any reference to the various phases which it assumed as the work advanced. In the grand general view which he takes, the land and seas first made represent those of all the following periods. So do the first plants, the first invertebrate animals, the first fishes, reptiles, birds, and mammals. He thus assures us that, however long the periods represented by days of creation, the system of nature was one from the beginning. In like manner in the geological record each of the successive conditions of the earth is related to those which precede and those which follow, as part of a series. So also a uniform plan of construction pervades organic nature, and uniform laws the inorganic world in all periods. We can thus include in one system of natural history all animals and plants, fossil as well as recent, and can resolve all inorganic changes into the operation of existing laws. The former of these facts is in its nature so remarkable as almost to warrant the belief of special design. Naturalists had arranged the existing animals and plants, without any reference to fossil species, in kingdoms, sub-kingdoms, classes, orders, families, and genera. Geological research has added a vast number of species not now existing in a living state; yet all these fossils can be inserted within the limits of recognized groups. We do not require to add a new kingdom, sub-kingdom, or class; but, on the contrary, all the fossil genera and species go into the existing divisions, in such a manner as to fill them up precisely where they are most deficient, thus occupying what would otherwise be gaps in the existing system of nature. The principal difficulty which they occasion to the zoologist and botanist is that, by filling the intervals between genera previously widely separated, they give to the whole a degree of continuity which renders it more difficult to decide where the boundaries separating the groups should be placed.
We also find that the animals and plants of the earlier periods often combined in one form powers and properties afterward separated in distinct groups; thus in the earlier formations the sauroid fishes unite peculiarities afterward divided between the fish and reptiles, constituting what Agassiz has called a synthetic type. Again, the series of creatures in time accords with the ranks which a study of their types of structure induces the naturalist to assign them in his system; and also within each of the great sub-kingdoms presents many points of accordance with the progress of the embryonic development of the individual animal. Nor is this contradictory to the statement that the earlier representatives of types are often of high and perfect organization, for the progress both in geological time and in the life of the individual is so much one of specialization that an immature animal often presents points of affinity to higher forms that disappear in the adult. In connection with this, earlier organic forms often appear to foreshadow and predict others that are to succeed them in time, as the winged and marine reptiles of the Mesozoic foreshadow the birds and cetaceans. Agassiz has admirably illustrated these links of connection between the past and the present in the essay on classification prefixed to his "Contributions to the Natural History of America." In reference to "prophetic" types, he says: "They appear now like a prophecy in those earlier times of an order of things not possible with the earlier combinations then prevailing in the animal kingdom, but exhibiting in a later period in a striking manner the antecedent consideration of every step in the gradation of animals."
4. The periods into which geology divides the history of the earth are different from those of Scripture, yet when properly understood there is a marked correspondence. Geology refers only to the fifth and sixth days of creation, or, at most, to these with parts of the fourth and seventh, and it divides this portion of the work into several eras, founded on alternations of rock formations and changes in organic remains. The nature of geological evidence renders it probable that many apparently well-marked breaks in the chain may result merely from deficiency in the preserved remains; and consequently that what appear to the geologist to be very distinct periods may in reality run together. The only natural divisions that Scripture teaches us to look for are those between the fifth and sixth days, and those which within these days mark the introduction of new animal forms, as, for instance, the great reptiles of the fifth day. We have already seen that the beginning of the fifth day can be referred almost with certainty to the Palæozoic period. The beginning of the sixth day may with nearly equal certainty be referred to that of the Tertiary era. The introduction of great reptiles and birds in the fifth day synchronizes and corresponds with the beginning of the Mesozoic period; and that of man at the close of the sixth day with the commencement of the Modern era in geology. These four great coincidences are so much more than we could have expected, in records so very different in their nature and origin, that we need not pause to search for others of a more obscure character. It may be well to introduce here a tabular view of this correspondence between the geological and Biblical periods, extending it as far as either record can carry us, and thus giving a complete general view of the origin and history of the world as deduced from revelation and science. In comparing this table with that on page 330, it will be observed that the latter refers to the last half of the creative week only, the earlier half being occupied with physical changes which, however probable inferentially, are not within the scope of geological observation.