Three possi2. Accepting the view that sensations are occable theories. sioned by corporeal affections, we have yet to choose between several theories respecting the efficiency producing

sensation.

First, it has been taught that the power producing sensation is exercised wholly by the body, and that the soul is wholly passive. When lightning tears open the roof of some building, or the electric spark pierces the paper subjected to its passage, the roof or the paper does not actively contribute to the result. A stone flung into the air does not originate any of the force by which it is propelled; it is entirely recipient and devoid of exertion. So the soul might be considered wholly passive in sensation; it might be likened to a placid lifeless pool whose rippling motions are made by the breezes only.

Again, it has been contended that the efficiency producing sensation resides wholly in the soul, and does not rise at all from the affections of our sensory system. When a child becomes interested in some pretty toy and seeks it, the toy cannot be supposed to be the efficient cause of the excitement of the child's desires. These, indeed, without the view of the toy, could not have arisen; but the whole power in the case belongs to the infantile soul itself. As, therefore, the intellect and the motivities of man act with an efficiency independent of their objects, so, it is argued, the power of sense acts without any external stimulus, and simply on the occasion of changes in the nerves.

Finally, it may be conjectured that the efficiency producing sensation belongs partly to the body and partly to the mind. When a blow discharges a percussion cap, the effect depends on the detonating powder quite as much as on the force of the blow. So, when a vessel of water at a low temperature and perfectly still, is shaken a little, it immediately turns to ice; and when certain solutions are mingled, they effervesce and form new compounds. In these cases the shaking and the mingling do not produce the effect so much as other causes which these bring into play. The question, therefore, suggests itself, whether our sensations, even though efficiently caused by bodily affections, are not also due partly to the active power of the soul.

cause of sen

twofold.

We incline to

Of these theories we prefer the last. The efficient the opinion that the efficient cause of sensation does sation is not belong exclusively either to the body or to the mind, but is a combination, partly physical, partly spiritual. The motion of the bow of the violin produces that of the string, yet only in part; the tightness and elasticity of the string contribute. So nervous changes affect the mind;

while yet this affection is not purely passive, but results also in part from a power of action belonging to the soul itself.

That sensation is truly caused by physical changes Partly external and is implied in those natural judgments which men physical. continually make. We say that the wind makes us cold, that the fire warms us, that sound affects our ears, scent our nostrils, light our eyes, and so forth. Thus we refer these feelings to various physical causes, which act upon our bodily frame, and upon our souls as inhabiting the body. We also make an important distinction between what is merely an object of cognition and what is a cause of sensation. In cognition, the activity and its causation are regarded as wholly mental; in sensation, the prominent efficiency presented in perceptive thought is physical. These natural judgments accord with critical inquiry. A scrutiny of the conditions of sensation easily produces instances in which no other antecedent can be found than some affection of the nervous system. Moreover, the researches of anatomy and surgery show, to a demonstration, on what branches and filaments of the sensory system our bodily feelings severally depend. In short, no fact of physical science is more certain than this, which belongs to mental science also, that sensation results from an excitement of the nerves.

At the same time some considerations support the belief that the soul is not wholly passive in sensation, but that it exercises an efficiency of its own.

Partly in

1. Because of

powers.

This is suggested by the analogy of our other ternal and psychical operations. In thought, sensibility, depsychical: sire, and action, man is conscious of self-activity. the analogy He perceives that each of these modes of experiof our other ence has no causal antecedents other than psychical, and can be ascribed to no efficiency other than that belonging to the soul itself. He therefore regards them as coming from a spring within. External objects may interrupt and modify the current of mental life, but they are not necessary to its continuance. The soul, once aroused to movement, lives on with an activity perpetual and inherent.

Moreover, although, during man's earthly existence, his psychical experience has been made dependent on bodily conditions, there is no evidence that it originates from them. On the contrary, easily distinguishing the spiritual activities, of which he is conscious, from all physical phenomena, man intuitively recognizes these activities and their powers as belonging not to his body, but to a substance other than his body, — that is, to his true self, or spirit; and so, as we have said, he regards the soul as selfactive, because the greater and essential part of its experience,

however dependent upon corporeal conditions, is perceived to originate, not from them, but from the soul itself. If every other psychical experience may be thus traced to the working of some inward power, may not sensation, likewise, be considered as resulting, in part at least, from the soul's own activity?

2.

Because

of the peculiarity of the effect.

To this conclusion we are led, also, by the following consideration. When one substance acts on another which is perfectly passive, the effect is of the same general character with the action by which it is caused. One stone, for example, striking another, transmits its own motion and nothing more. But when the effect is of a new and peculiar character, we find the cause partly also in the substance affected. The cause of the explosion of the percussion cap is found more in the detonating powder than in the blow; and the new compound from mixed fluids results more from chemical affinities than from the commingling. Now the nature of sensation, like that of our other psychical experiences, is revealed to us through consciousness, without which power we could not have the remotest conception of spiritual things; and we know that sensation is something extremely dissimilar to physical changes of any kind, so much so that we can scarcely compare it with them in any way. What likeness does any material process bear to the pain of toothache or of rheumatism, and what chemical or mechanical operation can be compared to the satisfaction of hunger or the gratification of taste? Sometimes we describe a sensation by mentioning the physical action by which it may be produced, - as, for example, the sensation of being struck or cut or burned, — but we distinguish the outward action and the inward experience as being very different. Some generic likeness, perhaps, can be found in sensations to other and higher feelings with which pain and pleasure are also specially connected, such as joy, sorrow, hope, fear, love, hatred ; but we can discover no resemblance in them to any physical phenomena. Such being the case, it is reasonable to believe that sense is not merely a capacity, but a capability; and that the mind, the substance in which sense inheres, itself contributes to the efficiency producing sensation.

reactions of mind on body.

3. Because Finally, the activity of the soul in sensation is sugof certain gested by certain reactions of mental upon physical life, which result in bodily feelings more or less defined. In certain exceptional cases, which can be easily distinguished, sensations seem to originate from psychical efficiency, no external excitant being present; for example, purely intellectual feelings-that is, those emotions which result from thought and which are not the consequence of

bodily changes are sometimes accompanied with sensations. Surprise causes a startling sensation; disappointment, a sinking feeling in the breast; fear produces chilliness. In short, corporeal feelings generally attend any violent mental disturbance. Here it may be objected that, in such cases, sensation is not directly produced by psychical efficiency, but only indirectly and through an affection of the nerves. Possibly this may be so; such instances certainly evince that the soul can act on the sensorium as well as the sensorium on the soul.

It may, however, be more to our present purpose to remark that imaginative ideas in dreaming, and even in wakeful hours, sometimes cause sensations, as if some reality had taken place; and the sensations thus excited seem also to produce nervous changes, such as at other times produce them. The order of causation appears to be reversed. Instead of nervous change, sensation, thought, we have thought, sensation, nervous change. In dreams, especially, our sensations often appear to be more than mere imaginings; we experience, though in feeble measure, the pains and pleasures of real life. How often, too, we meet with those who assert that they have heard the voices or seen the faces of absent friends, themselves creating what they hear or see! Various experiments may illustrate this power of the mind to originate its own sensations. Should a sharp needle be directed towards the middle of one's forehead, and advanced steadily, a singular feeling is experienced, at least by nervous people, at the place where the point of the needle is expected. This must result from the mind's own activity. Moreover, the soul, when specially interested, appears to have the power of adding to the natural keenness of any sense. When we listen or gaze, or even touch, taste, or smell, attentively, new delicacy is given to the organ. It is said to be innervated; and this innervation is probably an increase of that efficiency which the soul exercises in sensation, and is similar to the increase which special interest and effort produce in the energy of any other spiritual power.

Herbert Spencer testifies to the fact that thought does sometimes produce bodily feelings, though he does not use it as we have done. He says: "Ideas do, in some cases, arouse sensations. Several instances occur in my own experience. I cannot think of seeing a slate rubbed with a dry sponge without there running through me the same cold thrill that actually seeing it produces." As this reactionary movement of the mind depends on the recollection of things already perceived by the senses, it is an indication that the primary and proper source of sensation is the action of the body on the mind.

Materialism

CHAPTER VI.

CEREBRALISM, OR MATERIALISM.

1. THE doctrine which makes spirit only a refined defined. species of matter is called materialism. The essential Cerebralism. point in materialism is that sensation, thought, and spiritual experience generally, result simply from the operation of physical agents as such, or as acting in obedience to their own proper laws. This idea has been expressed sometimes by comparing psychical operations to those phenomena of light, heat, and electricity which take place during chemical and vital processes. In other words, materialism teaches, not merely that spirit is extended and has other attributes in common with matter; not merely even that spirit has all the essential attributes of matter, although no one save a materialist would say this; but also, and especially, that the life of spirit is purely a development of material forces.

Au

The modern adherents of this doctrine have frequently been styled cerebralists, because they derive psychical phenomena from certain supposed qualities of the brain and nerves. guste Comte, in his "Positive Philosophy," distrusts and contemns all facts save the physical and tangible, and finds in these an explanation of all phenomena. According to him, "the positive theory of the intellectual and affectional functions . . . is simply a prolongation of animal physiology, . . . from which it differs far less than this last differs from simple organic or vegetable physiology." Herbert Spencer and Alexander Bain are English psychologists, and Professors Tyndall and Huxley English scientific writers, who, with some modifications of thought and phraseology, have ideas essentially similar to those of Comte.

Let us note that the question presented by materialism is not identical with the question whether the soul and the body are two distinct existences. If this were the case, it would be easily settled. In every act of sense-perception the ego, or self, or soul, immediately distinguishes from itself the non-ego, or body, whose affections are the cause of our sensations. So also the ego immediately refers spiritual activities and powers to itself, and sense-affecting operations and powers to the non-ego. Thus soul and body are at once distinguished. But the statement of these facts, although they have an important bearing on the argument, is not the proper opposite of the materialistic theory. One might allow the distinct existence of soul and of body,