leading to a general agitation of the moving organs, as well as affecting the viscera."

There are probably no exceptions to the diffusion of every impression through the nerve-centres. The effect of a new wave through the centres may, however, often be to interfere with processes already going on there; and the outward consequence of such interference may be the checking of bodily activities in process of occurrence. When this happens it probably is like the siphoning of certain channels by currents flowing through others; as when, in walking, we suddenly stand still because a sound, sight, smell, or thought catches our attention. But there are cases of arrest of peripheral activity which depend, not on inhibition of centres, but on stimulation of centres which discharge outgoing currents of an inhibitory sort. Whenever we are startled, for example, our heart momentarily stops or slows its beating, and then palpitates with accelerated speed. The brief arrest is due to an outgoing current down the pneumogastric nerve. This nerve, when stimulated, stops or slows the heartbeats, and this particular effect of startling fails to occur if the nerve be cut.

In general, however, the stimulating effects of a senseimpression proponderate over the inhibiting effects, so that we may roughly say, as we began by saying, that the wave of discharge produces an activity in all parts of the body. The task of tracing out all the effects of any one incoming sensation has not yet been performed by physiologists. Recent years have, however, begun to enlarge our information; and we have now experimental proof that the heartbeats, the arterial pressure, the respiration, the sweatglands, the pupil, the bladder, bowels, and uterus, as well as the voluntary muscles, may have their tone and degree of contraction altered even by the most insignificant sensorial stimuli. In short, a process set up anywhere in the centres reverberates everywhere, and in some way or other affects the organism throughout, making its activities

either greater or less. It is as if the nerve-central mass were like a good conductor charged with electricity, of which the tension cannot be changed at all without changing it everywhere at once.

Herr Schneider has tried to show, by an ingenious zoölogical review, that all the special movements which highly evolved animals make are differentiated from the two originally simple movements of contraction and expansion in which the entire body of simple organisms takes part. The tendency to contract is the source of all the self-protective impulses and reactions which are later developed, including that of flight. The tendency to expand splits up, on the contrary, into the impulses and instincts of an aggressive kind, feeding, fighting, sexual intercourse, etc. I cite this as a sort of evolutionary reason to add to the mechanical a priori reason why there ought to be the diffusive wave which a posteriori instances show to exist.

I shall now proceed to a detailed study of the mor important classes of movement consequent upon cerebro、 mental change. They may be enumerated as—

1) Expressions of Emotion;

2) Instinctive or Impulsive Performances; and
3) Voluntary Deeds;

and each shall have a chapter to itself.

CHAPTER XXIV.

EMOTION.

Emotions compared with Instincts.-An emotion is a tendency to feel, and an instinct is a tendency to act, char acteristically, when in presence of a certain object in the environment. But the emotions also have their bodily expression,' which may involve strong muscular activity (as in fear or anger, for example); and it becomes a little hard in many cases to separate the description of the 'emotional' condition from that of the 'instinctive' reaction which one and the same object may provoke. Shall fear be described in the chapter on Instincts or in that on Emotions? Where shail one describe curiosity, emulation, and the like? The answer is quite arbitrary from the scientific point of view, and practical convenience may decide. As inner mental conditions, emotions are quite indescribable. Description, moreover, would be superfluous, for the reader knows already how they feel. Their relations to the objects which prompt them and to the reactions which they provoke are all that one can put ɑown in a book.

Every object that excites an instinct excites an emotion as well. The only distinction one may draw is that the reaction called emotional terminates in the subject's own body, whilst the reaction called instinctive is apt to go farther and enter into practical relations with the exciting object. In both instinct and emotion the mere memory or imagination of the object may suffice to liberate the excitement. One may even get angrier in thinking over one's insult than one was in receiving it; and melt more over a mother who is dead than one ever did when she was living. In

the rest of the chapter I shall use the word object of emotion indifferently to mean one which is physically present or one which is merely thought of.

The varieties of emotion are innumerable. Anger, fear, love, hate, joy, grief, shame, pride, and their varieties, may be called the coarser emotions, being coupled as they are with relatively strong bodily reverberations. The subtler emotions are the moral, intellectual, and æsthetic feelings, and their bodily reaction is usually much less strong. The mere description of the objects, circumstances, and varieties of the different species of emotion may go to any length. Their internal shadings merge endlessly into each other, and have been partly commemorated in language, as, for example, by such synonyms as hatred, antipathy, animosity, resentment, dislike, aversion, malice, spite, revenge, abhorrence, etc., etc. Dictionaries of synonyms have discriminated them, as well as text-books of psychology—in fact, many German psychological text-books are nothing but dictionaries of synonyms when it comes to the chapter on Emotion. But there are limits to the profitable elaboration of the obvious, and the result of all this flux is that the merely descriptive literature of the subject, from Descartes downwards, is one of the most tedious parts of psychology. And not only is it tedious, but you feel that its subdivisions are to a great extent either fictitious or unimportant, and that its pretences to accuracy are a sham. But unfortunately there is little psychological writing about the emotions which is not merely descriptive. As emotions are described in novels, they interest us, for we are made to share them. We have grown acquainted with the concrete objects and emergencies which call them forth, and any knowing touch of introspection which may grace the page meets with a quick and feeling response. Cenfessedly literary works of aphoristic philosophy also flash lights into our emotional life, and give us a fitful delight. But as far as the scientific psychology' of the emotions goes, I may have been surfeited by too much

reading of classic works on the subject, but I should as lief read verbal descriptions of the shapes of the rocks on a New Hampshire farm as toil through them again. They give one nowhere a central point of view, or a deductive or generative principle. They distinguish and refine and specify in infinitum without ever getting on to another 1ogical level. Whereas the beauty of all truly scientific work is to get to ever deeper levels. Is there no way out from this level of individual description in the case of the emotions? I believe there is a way out, if one will only take it.

The Cause of their Varieties.-The trouble with the emotions in psychology is that they are regarded too much as absolutely individual things. So long as they are set down as so many eternal and sacred psychic entities, like the old immutable species in natural history, so long all that can be done with them is reverently to catalogue their separate characters, points, and effects. But if we regard them as products of more general causes (as 'species' are now regarded as products of heredity and variation), the mere distinguishing and cataloguing becomes of subsidiary importance. Having the goose which lays the golden eggs, the description of each egg already laid is a minor matter. I will devote the next few pages to setting forth one very general cause of our emotional feeling, limiting myself in the first instance to what may be called the coarser emotions.

The feeling, in the coarser emotions, results from the bodily expression. Our natural way of thinking about these coarser emotions is that the mental perception of some fact excites the mental affection called the emotion, and that this latter state of mind gives rise to the bodily expression. My theory, on the contrary, is that the bodily changes follow directly the perception of the exciting fact, and that our feeling of the same changes as they occur Is the emotion. Common-sense says, we lose our fortune, are sorry and weep, we meet a bear, are frightened and run;