"Matter and Spirit," says Davis, "have heretofore been supposed to constitute two distinct and independent substances, the latter not having any material origin." ... "Instead of making material and spiritual existence totally disconnected, the object and intention of the foregoing has been to prove, by acknowledged laws and principles of matter, the production of intelligence, the perfection of which is spirit;" to show that "the Organizer uses Nature and all things therein as an effect, to produce spirit as an end and designed ultimate." The author of "The Purpose of Existence" adopts a similar view. He tells us, indeed, that "the first simple forms or states of existence are admitted to be two, spirit and matter,—the first the moving power, the second the moved substance;" that of the positive essence of either we can arrive at no knowledge; and that "whether spirit be a refined, etherealized portion of matter, or a distinct dynamic principle, we cannot ascertain." And yet, one of the leading objects of his work is to account for "the origin and development of the human mind;" and this he does by ascribing it to "a self-dynamic spirit which is resident in matter," and which he denominates "the spirit of vitality." The spirit exists in vegetables, and is extracted by means of the organs of the animals which feed upon them, and then, "by a delicate work of distillation, it is converted into spirit!"—"Nature proclaims one of her great working principles to be, that spirit is evolved out of matter, and outlives the body in which it is educated."—"Matter is full of spirit. This spirit is brought out of matter by vegetation. By means of vegetation, it is conveyed into animal frames, in which its purest essence centres in the brain.... This is no idle theory," he adds, "no vain hypothesis, for making matter think. It is a clear proposition, showing how matter is employed by the Supreme Intelligence for evolving, training, and educating spirit."—"We conclude that Progression is the great law of the universe, the purpose for which its present arrangement was ordained; and that the object of this progression is the evolvement of mind out of matter."
This is a new and very singular phase of Materialism. It is widely different from the doctrine which was taught by the infidel writers of the last century. They had recourse to the theory of Materialism chiefly with the view of excluding a world of spirits, and of undermining the doctrine of a future state: here it is applied to prove the constant development and indestructible existence of minds generated from matter, but destined to survive the dissolution of the body; nay, every particle of matter in the universe is supposed to be advancing, in one magnificent progression, towards the spiritual state. The danger now is, not that Religion may be undermined by Materialism, but that it may be supplanted by a fond and foolish superstition, in which the facts of Mesmerism and the fictions of Clairvoyance are blended into one ghostly system, fitted to exert a powerful but pernicious influence on over-credulous minds.[152]
On a review of the various forms which the theory of Materialism has assumed, it must be evident that we should be doing great injustice to their respective advocates, did we place them all on the same level in relation to Theology, or pronounce upon them one indiscriminate censure. In the hands of D'Holbach and Comte, it was associated with the avowal of Atheism, and the denial of a future state: in the hands of Priestley, it was associated with the recognition of a God, and the Christian doctrine of a resurrection: in the hands of Dr. Good, it was combined with the principles of Theism, and even with the revealed doctrine of the separate existence of the soul during the interval between death and the resurrection: and in the hands of Davis and the author of the "Purpose of Existence," it is exhibited in connection with a theory of Progression, widely different, indeed, from the doctrine of Scripture, but equally different from the infidel speculations of the last century. Still, with all these shades of difference, there is that common to all the forms in which it can be presented which shows that they are radically one and the same: they all deny the existence of any generic difference between Matter and Mind.
Confining our attention to this common element, and omitting the consideration of minor diversities, we may now inquire into the grounds on which the theory rests, and the most plausible reasons which have been urged in support of it.
To some minds it has been recommended by its apparent simplicity. It speaks only of one substance as existing in Nature under various modifications. It represents the universe, so far as created being is concerned, as entirely composed of matter, more or less refined; and thus excludes the complication which must necessarily arise from the supposition of two substances, generically different, yet intimately and indissolubly related. The principle, therefore, which prompts us to seek unity in diversity, and to reduce, by some comprehensive generalization, a multitude of phenomena under one general law, has led some to adopt the theory of unisubstancisme in preference to the opposite doctrine of dualism. Not content with the generalization, alike safe and legitimate, which ranks both mind and matter under the generic head of substance, they have sought to reduce them to the same category, and to give to matter a monopoly of the universe, at least of created being. In support of their views, they remind us of the fundamental principle of philosophy as laid down by Sir Isaac Newton, that "we are to admit no more causes of things than are sufficient to explain appearances."[153] The principle is a sound one; and the only question is, whether matter alone is sufficient to account for mental phenomena? On this question the two parties are at irreconcilable variance; and the controversy cannot be determined, brevi manû, by the mere assumption of the simplicity and uniform composition of everything in Nature; it can be settled only by an appeal to the facts as they are known to exist. It is the aim of science, undoubtedly, to reduce all compound substances to the smallest possible number of constituent elements, and all complex phenomena to the smallest possible number of general laws. But we feel that, desirable as this simplification may be, we are not warranted in identifying light with heat, or even electricity with magnetism, however closely connected with each other, simply because there are certain observed differences between them, which could not be explained, in the present state of our knowledge, consistently with any such theory of their absolute identity: and so, there are such manifest differences between Mental and Material phenomena, that we cannot yield to the temptation of ascribing them to one cause or origin, until it has been satisfactorily proved that the same cause is sufficient to account for appearances so diverse. It should be considered, too, in connection with this pretence of greater simplicity, that even if we could succeed in getting rid of the dualism of Mind and Matter in the constitution of man, we never can get rid of it with reference to the universe at large, otherwise than by denying the spirituality of God himself: for the grand, the indestructible, the eternal dualism would still remain,—the distinction between God and His works,—between the Creator and the universe which He has called into being,—between the finite, contingent, and transitory, and the infinite, necessary, and eternal. And this is a distinction that cannot be obliterated, although it may be obscured, by the speculations of Pantheism.
Another reason which has induced some to adopt, or at least to regard with favor, the theory of Materialism, is—the difficulty of conceiving of the union of two substances so incongruous as Mind and Matter are supposed to be,—and still more the difficulty of explaining how they could have any mutual action on each other. Dr. Priestley largely insists on this, as well as on the former reason, as one of the main inducements which led him to abandon the commonly-received doctrine. "Many doubts occurred to me," he says, "on the subject of the intimate union of two substances so entirely heterogeneous as the soul and body were represented to be." And he was led to conclude, that "man does not consist of two principles so essentially different from one another as matter and spirit, which are always described as having no one common property by means of which they can affect or act upon each other." In the "Systême de la Nature," the same argument is often urged. It is boldly and repeatedly affirmed that "an immaterial cause cannot produce motion;" and this is applied equally to the soul and to God. "How can we form an idea of a substance destitute of extension, and yet acting on our senses, that is, on material organs which are extended? How can a being without extension be capable of motion, and of putting matter into motion?"—"It is as impossible that spirit or thought should produce matter, as that matter should produce spirit or thought."[154]
Now, it is not denied by any,—it is admitted on all hands,—that the union between the soul and the body is a great mystery, and that we are not able, in the present state of our knowledge, to explain either the action of matter on mind, or the action of mind on matter. The mode of the union between them, and the nature of the influence which they mutually exercise, are to us inscrutable: but the facts of our most familiar experience are not the less certain, because they depend on causes to us unknown, or stand connected with mysteries which we cannot solve. Besides, the theory of unisubstancisme itself, were it adopted, would still leave many facts unexplained, and the inmost nature of man would continue to be as inscrutable as before. There is nothing inconceivable, impossible, or self-contradictory in the supposition of a non-material or spiritual substance; nor is there any reason a priori to conclude that such a substance could not be united to a material frame, although the nature of their union, and the mode of their reciprocal action, might be to us inexplicable.
There is still another reason which is urged by some, derived from the dependence of the mind on the body, and its liability to be affected, beneficially or injuriously, by mere physical influences. "The faculty of thinking," says Dr. Priestley, "in general ripens and comes to maturity with the body; it is also observed to decay with it,"—"If the brain be affected, as by a blow on the head, by actual pressure within the skull, by sleep, or by inflammation, the mental faculties are universally affected in proportion. Likewise, as the mind is affected in consequence of the affections of the body and brain, so the body is liable to be reciprocally affected by the affections of the mind, as is evident in the visible effects of all-strong passions,—hope or fear, love or anger, joy or sorrow, exultation or despair. These are certainly irrefragable arguments that it is properly no other than one and the same thing that is subject to these affections."[155] Mr. Atkinson urges the same reason. "The proof that mind holds the same relation to the body that all other phenomena do to material conditions, may be found," he tells us, "in the whole circumstances of man's existence, his origin and growth; the faculties following the development of the body in man and other animals; the direction of the faculties being influenced by surrounding circumstances; the desires, the will, the hopes, the fears, the habits, and the opinions, being effects traceable to causes,—to natural causes,—and becoming the facts of History and Statistics. We observe the influence of climate, of sunshine and damp, of wine and opium and poison, of health and disease." ... "When a glass of wine turns a wise man into a fool, is it not clear that the result is the consequence of a change in the material conditions?"[156]
Now, these facts are sufficient to show that, in the present life, there is a very close and intimate union between the soul and the body, and that they exert a reciprocal and very powerful influence. This is admitted by the firmest advocates of Spiritualism; nay, it is necessarily involved in the doctrine which they maintain, relative to the union of two distinct, but mutually dependent, principles in the present constitution of human nature. But it is far, very far, from affording any ground or warrant for the idea, that Matter may be identified with Mind, or Thought with Motion.
There are certain Theological considerations which, if they have not been pleaded as reasons, may yet have been felt as inducements, to the adoption of the theory of Materialism. Not to speak of the difficulty which has been felt in explaining "the traduction or propagation of human souls," occasionally referred to in this controversy, it is plain that many Deists in the last century, and that not a few Atheists still, have been induced to embrace and avow Materialism, with the view of undermining the doctrine of man's immortality, and of a future state of rewards and punishments. It is equally certain that Dr. Priestley was influenced by his peculiar views as a Socinian; for he tells us himself that the doctrine of Materialism commended itself to his mind as a sure and effectual means of disproving the preëxistence of Christ. "The consideration," he says with singular candor, "that biases me as a Christian, exclusive of philosophical considerations, against the doctrine of a separate soul, is, that it has been the foundation of what appears to me to be the very grossest corruptions of Christianity, and even of that very Antichristianism that began to work in the apostles' times, and which extended itself so amazingly and dreadfully afterwards. I mean the Oriental philosophy of the 'preëxistence of souls,' which drew after it the belief of the preëxistence and divinity of Christ, the worship of Christ and of dead men, and the doctrine of Purgatory, with all the Popish doctrines and practices that are connected with them, and supported by them."—"This doctrine (of the preëxistence of Christ) is the point to which all that I have written tends, it being the capital inference that I make from the doctrine of Materialism." There is also abundant reason to believe that both Atheists and Pantheists have had recourse to the theory of Materialism with the view of excluding the doctrine of a living, personal God, and explaining all the phenomena of Nature by the eternal laws of matter and motion. Now, if the question stands related in any way to such themes as these,—the immortality of man, the preëxistence and divinity of Christ, and the personality and spirituality of God,—it must be confessed to have at least a very high relative importance, as it bears on some of the most momentous articles of our religious faith; and the question naturally arises, What relation it bears to the fundamental principles of Theism, and how far it comports with right views of God, as the Creator and Governor of the world?