Wallace practically abandons his own ground, not only in his later works in ascribing much to natural selection which he was at first inclined to believe the effect of some supernatural cause, and omitting from his chapters on the application of the conception of evolution to man several arguments for supernatural intercession employed in his earlier work, but even in his first book, by admitting that natural selection takes advantage of mental superiority just as it does of physical superiority. We may notice at this point, however, a consistent inconsistency of his, in that, though he denies the existence of consciousness in matter, he leaves no logical room for the opposite theory of a gradual development of consciousness, since he asserts that all instinctive actions were at first self-conscious. This position is held by others also.
We may note here an objection of Wallace's that "because man's physical structure has been developed from an animal form by natural selection, it does not necessarily follow that his mental nature, even though developed pari passu with it, has been developed by the same causes only." The question may be again repeated as to what is meant by cause; and it will be well to keep distinct, in our thought, transcendental cause and cosmic conditions. We must admit that we have no proof of the absence of transcendental causes. Neither the constancy of nature nor the inseparability and indestructibility of matter and motion can prove the absence of such causes, which might be entirely consistent with these things; we have no data from which to argue that they are not so.
But though the law of Excluded Middle must hold good here as elsewhere, it is also to be noticed that the absence of proof in the natural order of things, with respect to the non-existence of transcendental causes, is not equivalent to the presence of proof of the opposite. We cannot infer, from the fact that no proof can be given of the non-existence of transcendental causes, that therefore proof can be given of the existence of such causes; or, from the fact that transcendental causes may be, that therefore transcendental causes are; they may also not be. There is, in fact, absence of proof for either view. Of the transcendental, if it exists, we can know by definition absolutely nothing. The man who endeavors to prove its existence generally bases his argument on this very fact in order to disprove the validity of any argument of his opponent from natural facts; when he, therefore, after legitimately silencing his opponent, goes on himself to prove the transcendental, he is guilty of self-contradiction. When Fiske asserts that there is no problem "in the simplest and most exact departments of science which does not speedily lead us to a transcendental problem that we can neither solve nor elude,"[129] we may admit the point, but surely it does not follow, because we cannot solve it, that therefore we must solve it, far less that we must solve it in one particular way. If we cannot solve it, we cannot solve it, and there is an end to the matter, unless we find new proof. We may not be able, as Fiske says, to elude the problem, but we certainly are able to elude the answering of it, and must do so perforce if the first part of the assertion,—namely, that we cannot answer it,—be correct. When Fiske urges us to accept one view because "the alternative view contains difficulties at least as great," we fail to perceive any grounds in this position for such acceptance. To Fiske's question as to whether we are to regard the work of the Creator as like that of the child, who builds houses just for the pleasure of knocking them down again, we may answer that the existence of a Creator must first be proved before we, from a scientific basis, may make any inference as to his purpose; and that we certainly cannot use an assumption of his existence in order to protest against a theory of Disteleology,—as Fiske seems to do,—if we use the teleological argument to prove his existence.
We may furthermore protest against the elevation of any negative term, as, for instance, Spencer's "Unknowable," to a term signifying a positive existence. We do not know whether there is any positive Transcendental that is to us unknowable; this mere negative term is admissible only on the assumption that it expresses such an absence of knowledge. The Unknowable assumed as existent entity is the Unknowable known,—a self-contradiction.
A similar criticism may be applied to Spencer's use in his "First Principles" of the word "Force," spelled with a capital, and defined as designating "Absolute Force," an "Absolute, Unconditioned Reality," "Unconditioned Cause,"[130] etc. The attribution of reality to a mere mental abstraction is a survival of old conceptions repudiated by Spencer in their older form. Of forces we know much, but of abstract Force nothing,—except as an abstraction from reality; and the dangers in the use of such a term are made manifest by Spencer's elevation of this concept to the character assigned it by the other terms quoted.
To sum up. We have found in nature only variables, no constant and invariable factor, no independent one according to which the others vary; we have found no cause that was not also an effect; that is, we have discovered nothing but a chain of phenomena bearing constant relations to each other, no causes except in this sense. We have no precedent or data from which to assert that chemical combinations could not have resulted in protoplasm and in living protoplasm, no data from which to assert that mere evolution could not have produced consciousness. As a matter of fact, however, we find the relations of consciousness and physiological process as constant as those of the different forms of material force, and while discovering no grounds upon which to pronounce either consciousness or physiological process the more essential, find none, either, for pronouncing one more than the other independent of what we call natural law. The logic of all our experience leads us to believe that neither protoplasm, nor the earth, nor any of the parts of the universe, could have originated otherwise than under natural law, that is, as the result of preceding natural conditions which must have contained all the factors united in the result, and would thus explain to us, if we knew them, in as far as any process is explained by analysis, the results arising from them. We know matter and motion only as united; we know no state of absolute rest, and we have no grounds for supposing any initial state of such absolute rest, or any state in which motion not previously existent in the universe entered. On the other hand, we have no proof of the absence of consciousness outside animal life, and no proof of the non-existence of transcendental causes, though likewise no proof of their existence.
FOOTNOTES:
[112] "Origin of Species," 6th ed., Vol. I. p. 320.
[113] "Lecture on Cell-souls and Soul-cells," 1878.
[114] "Entwicklungsgeschichte des Weltalls," p. 349 et seq.