The attempt to connect definitely the results of psychological and physiologica function was made by G. H. Lewes. (Problems, third series, ii., prob. iii. chap. ii.) His analysis of the psychical process into three factors, sensation, grouping, and motor action, was obviously reached by help of physiological considerations; for sensation corresponds to the afferent apparatus, logical grouping to central nervous connexions, and motor action to the motor organs. This division is, however, open to the objection that it confuses elements of feeling and of intellection under the first factor (sensation or sensible affection). A like objection applies to the attempt of Horwicz to base psychological on physiological division by returning to the bipartite conception of mind as compounded of thought and desire. (See Psychol. Analysen, theil i. sect. 24.)

It may be added that pathological observations bear out the supposition that the physiological correlatives of feeling, thought, and volition, though not identical, overlap, so to speak. While the pathologist may distinguish forms of mental disturbance that have their primary source in a perversion of feeling (e.g., of the organic sensations), or of the intellectual functions (e.g., of the perceptive powers as shown in liability to hallucination), he tells us that there is no such thing as an isolated disturbance of any one of the three functions.1

The above analysis of mind into a number of co-ordinate functional activities is a "geographical as distinguished from a "geological" view of mental action. The geological view considers mind in its process of development, and distinguishes between lower and higher forms of psychosis corresponding to different stages of this development, as Sensation, Imagination, and Thought. These distinctions have, as we have seen, been erected into fundamental ones in certain systems of psychological classification. But, as will be shown presently, they are secondary differences, explicable by means of the fundamental distinctions here considered.*

§ 7. Strata or Grades of Consciousness: Attention. No analysis of the constituents of mind can overlook the fact that they present themselves in different degrees of distinctness or perfection. Our thoughts, our actions, take on according to circumstances more or less of the conscious attribute. Thus we have distinct or clearly-conscious ideas and ideas which are indistinct and but imperfectly grasped.

We may say then that there are different levels or heights. of mental life, according to the degree of consciousness involved. And this way of dividing mind may be regarded as supplementary to that qualitative division into dissimilar kinds of activity or function just dealt with. The lowest level of mental life properly so called is that of indistinct consciousness.

1 This is well contended in the case of the feelings and the cognitions by Mr. Mercier, The Nervous System and Mind, p. 228.

2 This division according to height seems to do duty for a division according to breadth in the psychological scheme of Dr. Thos. Brown, who divides mind into External Affections (sensations) and Internal Affections (intellectual and emotional states). Cf. below, Appendix A.

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This includes all that mass of vague sensation, thought, impulse, and feeling which forms the dim background of our clear mental life. Thus, for the most part, the sensations which accompany the organic processes, as digestion, respiration, and circulation, remain below the level of distinct consciousness. We are at almost every moment aware of the presence of vague feelings and thoughts, some of which may afterwards emerge into the full light of consciousness. This region may be marked off as that of the sub-conscious.

The distinguishing factor in all clearly conscious states of mind is the fixing and rendering definite of a particular mental content by an active direction of the attention. Thus I only have a clear and distinct perception of an object present to sight, or a well-defined bodily feeling, when I make this in a manner the object of attention. The act of attending is thus one main condition of vivid and clear consciousness. We have, then, two broadly-marked-off divisions of our mental life, the region of vague consciousness or the sub-conscious, and the region of clear consciousness or of attentive consciousness.

§ 7a. Unconscious Psychical Processes. The relations of consciousness to the sub-conscious have given rise to much discussion. According to some writers there is a region of the unconscious, that is to say, of psychical processes which do not enter into our conscious life in any measure. This region is apt to be identified by physiologists with those nervous processes which have no distinct psychical concomitant. From a psychological point of view however, as was remarked above, a nervous process merely as such does not come within the view of the psychologist at all. It is only as it has some rudiment of sensation or other properly psychical phenomenon attending it that it concerns the student of mind. Now it is presumable that there are psychical equivalents of many nervous processes connected with the lower regions of life (vegetative functions) which never, or only under exceptional circumstances, distinctly emerge into consciousness. At the same time they enter into and colour our mental life taken in its widest extent. Thus, as we shall see, the so-called organic sensations, to which we hardly ever distinctly attend, are the main constituent in what we call tone of mind or 'spirits'.

Others, like Sir W. Hamilton, urge from a strictly psychological point of view that we must postulate "unconscious mental modifications," i.e., unconscious sensations, thoughts, and so forth, in order to account for the phenomena of distinct consciousness. Thus they say we cannot explain the revival of a sense-presentation, e.g., a colour, under the form of an image without assuming the continued existence of the presentation as an unconscious mental state or content during the interval between its original occurrence and its revival. Such a supposition would doubtless aid us in explaining, by help of properly psychical processes, obscure facts of our mental life. But it is open to the grave objection that the idea of a mental

phenomenon, having no relation to our conscious life, is self-contradictory. This difficulty seems overcome in a measure by saying that all psychical phenomena lying beyond the confines of clear consciousness are constituents of the sub-conscious region of our mental life. As such they already exist as raw material for mind, and are susceptible by a special direction of attention of being brought into the texture of our distinctly-conscious life.1

§ 7b. Consciousness and Self-Consciousness. Consciousness is a troublesome word in psychology, and but for the need of a term to mark off the more vivid and distinct region of our mental life might well be dropped altogether. Among other drawbacks it is apt to be confused (e.g., by Hamilton) with self-consciousness. Now it is no doubt true that all our feelings, thoughts, and actions are affections or states of ourselves, and can under certain conditions be recognised as such. But it is not necessary that when thinking, acting, or feeling one should reflect on the fact that it is I or the Ego that does so. This reflective or introspective consciousness is a secondary and more complex variety of consciousness, involving an idea of self. Hence it does not appear distinctly in early life, and it holds but a very subordinate place in the mental life of many adults. We can only understand this variety of consciousness after we have traced the growth of the idea of self. According to our present view we may have clear consciousness without self-consciousness, as when, for example, a scientific man directs intellectual activity outwards in observing some physical process. Such a person is intensely conscious, that is, his mind is preternaturally active, and yet he may for the moment be wholly oblivious of self.

Consciousness, as the etymology of the word suggests, popularly refers par excellence to intellectual activity. To say I am conscious is another way of saying I am aware, or I know. Now such intellectual activity (as Hamilton has shown) enters into all those fully-elaborated processes of the human mind which involve the idea of self. Thus when we feel pain or will to do a thing we commonly have a more or less distinct intellectual awareness of the fact. But it is undesirable to confine the term consciousness to this complex and mature form. A pain so intense as to exclude all intellectual activity is still consciousness for the psychologist. The blind instinctive impulse that agitates a bird at the time of migration may contain no rudiment of reflective consciousness; yet it is a fact of consciousness. In the evolution of consciousness, as we shall see, all varieties of mental state tend to be reflected on, related one to another, and referred to a central meeting point or self. But we must not take this elaborated and intellectualised form of consciousness for consciousness in all its forms, crude as well

as mature.

87c. Function of Attention. It is evident from what has been said that Attention plays an important part in the economy of our mental life. The precise nature of its action, and of the mechanism by which it directs the mental processes, will

1 On the difficult question of the unconscious, see Sir W. Hamilton, Lectures on Metaphysics, vol. i. lect. xviii. (cf. J. S. Mill, Examination of Sir W. Hamilton's Philosophy, chap. xv.); G. H. Lewes, Physical Basis of Mind, prob. iii. chap. iv.; W. James, Principles of Psychology, i. p. 162 ff.; Wundt, Physiol. Psychologie, vol. ii. 4er abschnitt, 15er cap. 1, 2; Brentano, Psychologie, 2es buch, 2er cap.

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appear more plainly later on. It will be enough at this stage to briefly indicate its general function.

In the first place, then, the process of attention adds something to each variety of psychical phenomenon which it embraces. In the case of the presentations and representations which make up so large a part of the contents of our mind it secures increase of vividness and of definition or distinctness. In listening to a sound I secure a more forcible and more distinct impression. Hence, as we shall see presently, attention stands in a peculiarly close relation to the intellectual processes. It is by attending to the presentations which arise that we are able to "relate" them for purposes of knowledge.

At the same time, special directions of attention serve to reinforce the feelings and the active impulses. We can intensify a pain or a pleasure by attending to it as such. The directions of attention thus serve to modify and to determine our affective states. By refusing to attend to a bodily pain of slight intensity we may practically put an end to it. In volition, as already pointed out, attention is a main conditioning factor. In all new and unfamiliar actions, as we can see in watching children learning to execute movements, attention is deeply engaged.

According to Dr. Ward attention acts directly on the intellectual material of presentation, and the effect of attention on feeling is an indirect result of the intensification of the presentative element. This seems an exaggeration of the fact. No doubt most if not all feeling occurs along with some presentative element, and in attending to the feeling we necessarily embrace this also to some extent. But what we commonly call attending to our feelings differs from that mere attention to presentation for its own sake which subserves cognition. In the case of bodily feeling indeed, e.g., the pain of indigestion, it would often be difficult to say that attention is directed to any presentative element. And even in the case of the higher feelings the attention which intensifies feeling differs from the attention which furthers cognition. To listen to a musical sound so as to note its pitch, etc., and to listen to it solely for the sake of enjoying it, illustrate two different directions of the attention.

In the second place, the regulative function of attention serves to bring about a simplification and orderly arrangement of our mental life. The process of attention is selective, and helps to give prominence at the moment to some particular mental content. In this way, as will appear more plainly by-and-by, the successive movements of attention, so far as they

enter into our psychical processes, tend to reduce the multplicity of sensuous and other elements which present themselves to a single thread of connected events which we can afterwards more or less completely retrace, and by retracing which we develop that highest form of consciousness marked off as self-consciousness.

While, however, we thus at the outset assign so unique a place and so prominent a function to attention, we have to admit that in all its more energetic degrees it is but an occasional ingredient of consciousness. Not only does the region of organic life but rarely become the object of such close attention; the higher plane of conscious life, including sensation, voluntary movement, and the intellectual processes, involves less and less of the concentrative element as these processes recur and grow familiar. In other words, though attention is an essential ingredient in all acquisitive stages, where new impressions have to be assimilated, new movements to be mastered, new relations of ideas to be distinctly apprehended, it can be dispensed with in proportion as the psychical process grows habitual by repetition. In this case the nervous mechanism with which our mental life is correlated comes into new prominence. Actions which involved concentrated consciousness at first, when the appropriate nervous connexions were imperfectly established, may lapse out of clear consciousness altogether when these nervous connexions are complete.

7d. Biological View of Attention.

If, as the biologist would say, all psychical processes are a part of the adjustive action of organism to environment in which life consists, we may regard the specialised form of consciousness that we call attention as a necessary condition in all the earlier and more difficult stages of this adjustment. The less familiar, the less customary, the action to be performed, the closer the attention required. As the adjustment advances, through repeated performance of the new action, this last growS smoother, easier, and more rapid, involving less and less of conscious effort, till at last it may become, as in the case of walking and other habitual actions, almost completely mechanical and unconscious. That is to say, the nervous system has more completely adjusted itself to the new demand of the environment by the formation of firmly-established co-ordinations or connexions among the several central elements involved.

By this arrangement it is evident nervous force is economised. The highest nerve-centres which are presumably energetically at work in cases of concentrated attention are able to cast off, so to speak, work in the degree in which it grows customary, so as to be free to engage in new tasks.