Rationalism—and by rationalism I mean the doctrine that abides solely by reason, by objective truth—is necessarily materialist. And let not idealists be scandalized thereby.
The truth is—it is necessary to be perfectly explicit in this matter—that what we call materialism means for us nothing else but the doctrine which denies the immortality of the individual soul, the persistence of personal consciousness after death.
In another sense it may be said that, as we know what matter is no more than we know what spirit is, and as matter is for us merely an idea, materialism is idealism. In fact, and as regards our problem—the most vital, the only really vital problem—it is all the same to say that everything is matter as to say that everything is idea, or that everything is energy, or whatever you please. Every monist system will always seem to us materialist. The immortality of the soul is saved only by the dualist systems—those which teach that human consciousness is something substantially distinct and different from the other manifestations of phenomena. And reason is naturally monist. For it is the function of reason to understand and explain the universe, and in order to understand and explain it, it is in no way necessary for the soul to be an imperishable substance. For the purpose of explaining and understanding our psychic life, for psychology, the hypothesis of the soul is unnecessary. What was formerly called rational psychology, in opposition to empirical psychology, is not psychology but metaphysics, and very muddy metaphysics; neither is it rational, but profoundly irrational, or rather contra-rational.
The pretended rational doctrine of the substantiality and spirituality of the soul, with all the apparatus that accompanies it, is born simply of the necessity which men feel of grounding upon reason their inexpugnable longing for immortality and the subsequent belief in it. All the sophistries which aim at proving that the soul is substance, simple and incorruptible, proceed from this source. And further, the very concept of substance, as it was fixed and defined by scholasticism, a concept which does not bear criticism, is a theological concept, designed expressly to sustain faith in the immortality of the soul.
William James, in the third of the lectures which he devoted to pragmatism in the Lowell Institute in Boston, in December, 1906, and January, 1907[26]—the weakest thing in all the work of the famous American thinker, an extremely weak thing indeed—speaks as follows: "Scholasticism has taken the notion of substance from common sense and made it very technical and articulate. Few things would seem to have fewer pragmatic consequences for us than substances, cut off as we are from every contact with them. Yet in one case scholasticism has proved the importance of the substance-idea by treating it pragmatically. I refer to certain disputes about the mystery of the Eucharist. Substance here would appear to have momentous pragmatic value. Since the accidents of the wafer do not change in the Lord's Supper, and yet it has become the very body of Christ, it must be that the change is in the substance solely. The bread-substance must have been withdrawn and the Divine substance substituted miraculously without altering the immediate sensible properties. But though these do not alter, a tremendous difference has been made—no less a one than this, that we who take the sacrament now feed upon the very substance of Divinity. The substance-notion breaks into life, with tremendous effect, if once you allow that substances can separate from their accidents and exchange these latter. This is the only pragmatic application of the substance-idea with which I am acquainted; and it is obvious that it will only be treated seriously by those who already believe in the 'real presence' on independent grounds."
Now, leaving on one side the question as to whether it is good theology—and I do not say good reasoning because all this lies outside the sphere of reason—to confound the substance of the body—the body, not the soul—of Christ with the very substance of Divinity—that is to say, with God Himself—it would appear impossible that one so ardently desirous of the immortality of the soul as William James, a man whose whole philosophy aims simply at establishing this belief on rational grounds, should not have perceived that the pragmatic application of the concept of substance to the doctrine of the Eucharistic transubstantiation is merely a consequence of its anterior application to the doctrine of the immortality of the soul. As I explained in the preceding chapter, the Sacrament of the Eucharist is simply the reflection of the belief in immortality; it is, for the believer, the proof, by a mystical experience, that the soul is immortal and will enjoy God eternally. And the concept of substance was born, above all and before all, of the concept of the substantiality of the soul, and the latter was affirmed in order to confirm faith in the persistence of the soul after its separation from the body. Such was at the same time its first pragmatic application and its origin. And subsequently we have transferred this concept to external things. It is because I feel myself to be substance—that is to say, permanent in the midst of my changes—that I attribute substantiality to those agents exterior to me, which are also permanent in the midst of their changes—just as the concept of force is born of my sensation of personal effort in putting a thing in motion.
Read carefully in the first part of the Summa Theologica of St. Thomas Aquinas the first six articles of question lxxv., which discuss whether the human soul is body, whether it is something self-subsistent, whether such also is the soul of the lower animals, whether the soul is the man, whether the soul is composed of matter and form, and whether it is incorruptible, and then say if all this is not subtly intended to support the belief that this incorruptible substantiality of the soul renders it capable of receiving from God immortality, for it is clear that as He created it when He implanted it in the body, as St. Thomas says, so at its separation from the body He could annihilate it. And as the criticism of these proofs has been undertaken a hundred times, it is unnecessary to repeat it here.
Is it possible for the unforewarned reason to conclude that our soul is a substance from the fact that our consciousness of our identity—and this within very narrow and variable limits—persists through all the changes of our body? We might as well say of a ship that put out to sea and lost first one piece of timber, which was replaced by another of the same shape and dimensions, then lost another, and so on with all her timbers, and finally returned to port the same ship, with the same build, the same sea-going qualities, recognizable by everybody as the same—we might as well say of such a ship that it had a substantial soul. Is it possible for the unforewarned reason to infer the simplicity of the soul from the fact that we have to judge and unify our thoughts? Thought is not one but complex, and for the reason the soul is nothing but the succession of co-ordinated states of consciousness.
In books of psychology written from the spiritualist point of view, it is customary to begin the discussion of the existence of the soul as a simple substance, separable from the body, after this style: There is in me a principle which thinks, wills, and feels.... Now this implies a begging of the question. For it is far from being an immediate truth that there is in me such a principle; the immediate truth is that I think, will, and feel. And I—the I that thinks, wills, and feels—am immediately my living body with the states of consciousness which it sustains. It is my living body that thinks, wills, and feels. How? How you please.
And they proceed to seek to establish the substantiality of the soul, hypostatizing the states of consciousness, and they begin by saying that this substance must be simple—that is, by opposing thought to extension, after the manner of the Cartesian dualism. And as Balmes was one of the spiritualist writers who have given the clearest and most concise form to the argument, I will present it as he expounds it in the second chapter of his Curso de Filosofia Elemental. "The human soul is simple," he says, and adds: "Simplicity consists in the absence of parts, and the soul has none. Let us suppose that it has three parts—A, B, C. I ask, Where, then, does thought reside? If in A only, then B and C are superfluous; and consequently the simple subject A will be the soul. If thought resides in A, B, and C, it follows that thought is divided into parts, which is absurd. What sort of a thing is a perception, a comparison, a judgement, a ratiocination, distributed among three subjects?" A more obvious begging of the question cannot be conceived. Balmes begins by taking it for granted that the whole, as a whole, is incapable of making a judgement. He continues: "The unity of consciousness is opposed to the division of the soul. When we think, there is a subject which knows everything that it thinks, and this is impossible if parts be attributed to it. Of the thought that is in A, B and C will know nothing, and so in the other cases respectively. There will not, therefore, be one consciousness of the whole thought: each part will have its special consciousness, and there will be within us as many thinking beings as there are parts." The begging of the question continues; it is assumed without any proof that a whole, as a whole, cannot perceive as a unit. Balmes then proceeds to ask if these parts A, B, and C are simple or compound, and repeats his argument until he arrives at the conclusion that the thinking subject must be a part which is not a whole—that is, simple. The argument is based, as will be seen, upon the unity of apperception and of judgement. Subsequently he endeavours to refute the hypothesis of a communication of the parts among themselves.