4. The Bible indicates some ways in which creatures may be modified or changed into new species, or may give rise to new forms of life. The human body is, we are told, capable of transformation into a new or spiritual body, different in many important respects, and the future general prevalence of this change is an article of religious faith. The Bible represents the woman as produced from the man by a species of fission, not known to us as a natural possibility, except in some of the lower forms of life. The birth of the Saviour is represented as having been by parthenogenesis, and if it had pleased God that Jesus was to remain on earth as the progenitor of a new and higher type of man to replace that now existing, this might be regarded as the introduction of a new species. To what extent the Creator may have so acted on the constitution of organized beings as to produce changes of this kind we have no means of knowing; but if he have done so, we may be sure that it has been in accordance with some definite plan or law.
5. We have a right to infer from Scripture that there must be some creative law which provides for the introduction of species, de novo, from unorganized matter, and which has been or is called into action by conditions as yet altogether unknown to us, and as yet inimitable, and therefore in some sense miraculous. Whether we shall ever by scientific investigation discover the law of this kind of divine intervention it is impossible to say. That all the theories of spontaneous generation and derivation hitherto promulgated are but wild guesses at it is but too evident.
6. Since in inorganic nature we meet with such ultimate facts as atoms of different kinds and with different properties; and ether of non-atomic constitution, all of which seem to be necessary to the existence of the world as it is, we may expect in like manner to find at the basis of organic structures and phenomena varied kinds of ultimate organisms and forces, probably much more complicated than those of inorganic nature. The broad simplicity of existing theories of derivation and evolution is thus in itself a presumption against their truth, except as very partial explanations.
7. We have no right to consider the species "after their kinds" of revelation as coincident with the species recognized by science. Many of these may be merely races, the production of which in the course of time and in special circumstances may fall within the powers of created species, and which may merely be the phases of such species in time and place. Only the accumulation of vast additional stores of facts can enable us to have any certain opinion on this point, and till it is settled the doctrine of derivation must remain purely hypothetical.
8. The inference of evolutionists that because certain forms of life succeed each other in geological time, they must have been derived from each other, has an aspect of truth and simplicity; but the idea of law or plan in creation suggests that the link of connection may be of a less direct nature than mere descent with modification. This has been referred to under a previous head.
9. In the scheme of revelation all the successions and changes of organized beings, just as much as their introduction at first, belong to the will and plan of God. Revelation opposes no obstacle to any scientific investigation of the nature and method of this plan, nor does it contemplate the idea that any discoveries of this kind in any way isolate the Creator from his works. Farther, inasmuch as God is always present in all his works, one part of his procedure can scarcely be considered an "intervention" any more than another.
10. As an illustration of the hypothetical condition of this subject, and of the views which may be taken as to its details, I quote from a memoir of my own certain conclusions with reference to the origin of the species of land plants which are found in the older geological formations. The conclusions stated are at the end of a detailed consideration of these plants and the circumstances of their occurrence:
"(1.) Some of the forms reckoned as specific in the Devonian and Carboniferous formations may be really derivative races. There are indications that such races may have originated in one or more of the following ways: (a) By a natural tendency in synthetic types to become specialized in the direction of one or other of their constituent elements. In this way such plants as Arthrostigma and Psilophyton may have assumed new varietal forms. (b) By embryonic retardation or acceleration, [151] whereby certain species may have had their maturity advanced or postponed, thus giving them various grades of perfection in reproduction and complexity of structure. The fact that so many Erian and Carboniferous plants seem to be on the confines of the groups of Acrogens and Gymnosperms may be supposed favorable to such exchanges. (c) The contraction and breaking up of floras which occurred in the Middle Erian and Lower Carboniferous may have been eminently favorable to the production of such varietal forms as would result from what has been called the 'struggle for existence.' (d) The elevation of a great expanse of new land at the close of the Middle Erian and the beginning of the Coal period would, by permitting the extension of series over wide areas and fertile soils, and by removing the pressure previously existing, be eminently favorable to the production of new, and especially of improved, varieties.
"(2.) Whatever importance we may attach to the above supposed causes of change, we still require to account for the origin of our specific types. This may forever elude our observation, but we may at least hope to ascertain the external conditions favorable to their production. In order to attain even to this it will be necessary to inquire critically, with reference to every acknowledged species, what its claims to distinctness are, so that we may be enabled to distinguish specific types from mere varieties. Having attained to some certainty in this, we may be prepared to inquire whether the conditions favorable to the appearance of new varieties were also those favorable to the creation of new types, or the reverse—whether these conditions were those of compression or expansion, or to what extent the appearance of new types may be independent of any external conditions, other than those absolutely necessary for their existence. I am not without hope that the further study of fossil plants may enable us thus to approach to a comprehension of the laws of the creation, as distinguished from those of the continued existence of species.
"In the present state of our knowledge we have no good ground either to limit the number of specific types beyond what a fair study of our material may warrant, or to infer that such primitive types must necessarily have been of low grade, or that progress in varietal forms has always been upward. The occurrence of such an advanced and specialized type as that of Syringoxylon in the Middle Devonian should guard us against these errors. The creative process may have been applicable to the highest as well as to the lowest forms, and subsequent deviations must have included degradation as well as elevation. I can conceive nothing more unreasonable than the statement sometimes made that it is illogical or even absurd to suppose that highly organized beings could have been produced except by derivation from previously existing organisms. This is begging the whole question at issue, depriving science of a noble department of inquiry on which it has as yet barely entered, and anticipating by unwarranted assertions conclusions which may perhaps suddenly dawn upon us through the inspiration of some great intellect, or may for generations to come baffle the united exertions of all the earnest promoters of natural science. Our present attitude should not be that of dogmatists, but that of patient workers content to labor for a harvest of grand generalizations which may not come till we have passed away, but which, if we are earnest and true to nature and its Creator, may reward even some of us." [152]