An Introduction to Comparative Psychology
Chapter 13: The Perception of Relations
C. Lloyd Morgan
THE complexity of consciousness is so intricate, and yet so orderly, that it is difficult to trace all the varied threads of our mental tapestry. In previous chapters. we have endeavoured, in our analysis, to pick out some of these threads. We have seen that in our visual impressions, sight being for us the dominant sense, retinal sensations coalesce or combine with motor sensations, and that seemingly simple impressions are therefore the products of a subtle synthesis. When we see a violet, the retinal sensations somewhat differently grouped in the two eyes, enter into synthetic union with certain motor sensations, the concomitants of movements of and within the eyeballs, whence arises an impression of a coloured and shaded object, possessed of a certain form, and located just there in the midst of a marginal field. But this impression forms the. nucleus around which representative elements cluster. The visual field, how it is lighted and how the shadows fall, the relative size of the subsidiary objects, their grouping around the focal object,-all these involve representative elements which serve, so to speak, to give further body to the mental picture, and which result from a vast amount of visual experience, whereby retinal and motor elements have entered into a close co-ordination. The violet is a visual impression; but it is something more, -- it is a centre of aggregation. Its fragrant odour, for example, is suggested; and for me, as I have before mentioned, a particular spot in a quaint old garden, often visited in childhood, has a ten-
(218) -dency to come to mind. That is to, say, violets have a strong tendency, through association, to form the focal starting-point of a representative visual scene.
So far we have been dealing with the presentative elements of impressions, and with their representative revivals. Impressions as such are constituted solely by presentative elements synthetically combined, though they may rapidly accrete around themselves in further synthesis representative elements; and these representative elements, so far as we have already considered them, are merely the revivals of those sensations which constitute the presentative elements. And here it may be well to add a reminder that we defined a sensation as an undecomposable element in consciousness, due to an afferent impulse, or a combination of afferent I impulses. Our analysis disclosed sensations of the special senses (retinal, auditory, olfactory, and so forth), sensations of pain and of general sensibility, motor sensations, and, it would seem, sensations of distance and solidity. These latter we found to be due to the combination of afferent impulses, which are probably physiological and infra-conscious. And it will be remembered that, in reply to the question, why the combination of certain infra-conscious impulses give's rise to a sensation having the quality of distance or of solidity, I said that I did not pretend to know. It is like the question why a combination of carbon and sulphur in certain proportions gives something so different from either constituent as the colourless liquid carbon disulphide. We can only say that, so far as we know, this is the way things are constituted. We here reach the limits of scientific analysis. In like manner of distance and solidity, we can only say that, tinder given conditions of stimulation, that is the form which impressions assume. Science cannot say why. Science has to be content with the fact that, so far as it is at present able to ascertain, this is the way in which such impressions are constituted.
But the important point for us to notice in the present connection is that outness, position in the visual field, and solidity, are already given in the visual impression, and that they acquire their significance for practical conduct through their correlation with tactual, auditory, and other impressions. This correlation is based on association; and what I have just termed "significance" is the suggestion of tactual, auditory, or other representative states on the occurrence of visual impressions. In and through this correlation the presentative elements, which our analysis has disclosed, together with their representative revivals, enter into fuller and more complex synthesis; but in the synthesis, these sensation elements (and their revivals), and these alone are present. If it be said that in addition to these elements there is the synthetic consentience itself which combines them into new mental compounds, I would reply that this is not only true, but is involved in the conception of psychology as a science. We study psychology in order that we may ascertain the laws of the combinations which lead to the genesis of mental products, just as we study chemistry that we may ascertain the laws of the combinations which lead to chemical products. If there were no synthetic activity in either case, there would be no science of psychology or of chemistry. Such activities in nature are what we endeavour to give a generalised statement of in the primary laws Of nature. These laws are, we believe, universal laws: The activities in question are not peculiar to and resident in individual units, whether these individuals be organisms or crystalline products of chemical combination. They are general or, in philosophic phrase, universal, and are manifested in the individual only ill so far as the individual is a constituent unit in the universal This is now freely admitted in chemistry and in biology; until it is as freely admitted for mental products, psychology will either fall below or soar above the level of science. From the strictly
(220) empirical point of view, it may be said that there is nothing in the impression or its idea but a synthesis of conscious sensations and infra-conscious impulses (or their revivals). And if a disciple of Leibnitz would bid us add, "Yes, nothing, save the synthetic principles which combines them," this may be freely admitted, on the distinct understanding that the synthetic "principle" is strictly analogous to the synthetic " principle " by which carbon and sulphur in due proportions combine to form carbon disulphide, or by which carbonate of lime crystallizes as calcite., And by strictly analogous I mean that in each case we are dealing with natural law. But if it be meant that the "principle " of synthesis is something supernatural,not the inner essence of the natural process, but something superadded thereto, -- then we must reject the hypothesis as unnecessary, and not in line with the results of investigation in other departments of knowledge. And this, I need hardly add, were it not that it is so easy for students of mental science to misunderstand each other, -- this, I say, is no denial of mental individuality. Such denial would be on the face of it absurd; it is merely the placing of mental individuality in line with organic individuality, as the natural product of the complex interaction of natural laws.
We have now to pass on to the consideration of other factors of mental products by the synthetic incorporation of which these products take on new and higher characters.
The visual impressions are different according as', the object is near or far, and located here or there in the visual field. We explain this by saying that. the object is seen in relation to other objects in space. But such explanation involves the perception of the relation as Such. Until the relation shall have been perceived, it is impossible to 'view the objects in the light of the relationship. And so long as we are dealing simply with impressions in naive sense-experience, the relationship need not yet have been
(221) perceived. The relations may have been implicitly there, but they may not yet have become explicit. They may not yet have been brought to the focus of consciousness. I look around me in my room, and fix my eyes, and my attention on this, on that, and on the other -familiar object. With each new centre of vision and of attention there is a new grouping of the visual scene in relation to a new focus. But as I do so, my mind need never for a moment dwell on the relationships of the objects to each other in space. Related in space they are, and, I can perceive the relations. But I may look around me for hours without paying any attention to them-without their ever coming to the focus of my consciousness. No doubt, the fact that such relations have been clearly grasped lends a subconscious relational tone to my mental synthesis. But for the little child, this is probably not so. For the child has not yet risen to the perception of relations; the relationships for him have, I conceive, never become focal. For him the mental products are impressions, and nothing more; for me they are percepts in so far as they carry with them this relational tone. A percept is an impression to which is added a conscious or subconscious perception of relation to the subject or to other objects. And we have now to endeavour to ascertain the psychological nature of the perception of relations.
As I look around me, and transfer my attention from one object to another, there is at each transference a transition in consciousness. If we symbolize by letters the succeed-
(222) -ing states of consciousness, we have a series which may be thus formulated : -
But consciousness is continuous. The states r s n, &c., are not isolated from one another, but form phases in a series, one of whose attributes is continuity. And we sense or are aware of the transitions as they pass. We do not fix our attention upon them. Our attention is engaged by the substantive states themselves. Our attention passes from r to s, and from s to n, and so on. The consciousness of transition is altogether marginal, and in the case of the little child has, I conceive, never become other than marginal. Let us try and think ourselves into the condition of earlychildhood. There are placed before us three wafers or counters, two red and one blue. We look at them in succession, so that first a red wafer, and then another red wafer, and then a blue wafer, occupies the focus of vision and of consciousness, the sequence therefore being red wafer-red wafer-blue wafer. As we do so we feel that there is a transition in consciousness, first from red to red, and then from red to blue. When the transition is from red to red, we sense or are aware that the focal impressions are "similar;" when the transition is from red to blue, we sense the focal impressions as dissimilar. Now here the point to be noticed is that the similarity or dissimilarity is not in the focal states themselves, but in the transitions from one to another. In the absence of the red wafer, there would be no sense of dissimilarity produced by the impression of the blue one. It is only when the attention is transferred from red to red, or from red, to blue, that we are aware of the similarity or dissimilarity between them. It must, however, be clearly understood that it is with the mere awareness of that which is interpreted by perception as similarity or dissimilarity that I am
(223) so far dealing. Our three wafers are moreover to be regarded as illustrative and representative of any kind of similarity or dissimilarity. Let us suppose that for the red wafers, there are substituted two sweets, and for the blue wafer, a piece of coal or chalk. A child who has as yet no clear perception of similarity may be aware of the likeness of one sweet to the other, and practically act upon this awareness, and may likewise be aware of the dissimilarity of the piece of coal or chalk to the sweets. So too a child may be subconsciously sensible of the similarity of two leaden bullets the one to the other, and of the dissimilarity of a clay marble to either of them, and yet have no clear perception of the relation of likeness or unlikeness.
It will be noticed that we are compelled to explain in terms of relationships (because we cannot explain in any other terms), the mental condition prior to the perception of relations. We are forced to use the words " similarity " and " dissimilarity," " likeness " and "unlikeness," for that mere awareness of a transition in consciousness, which in the light of perception will become (but is not yet) similarity or dissimilarity. We are inevitably driven to employ the language of anticipation. And I know not how better to make clear the distinction I would draw, than by laying stress upon the verb, and by saying that a little child endowed only with sense-experience, senses or is aware of the similarity between two sweets, and the dissimilarity between a sweet and a piece of chalk, but does not perceive the similarity or dissimilarity; or, to put it in another way, that he senses the sweets as similar, and the chalk as dissimilar, but tines not perceive the similarity or dissimilarity as a relation. And that because the sweets or the chalk monopolise the focus of consciousness, because the child has not yet had occasion to look within on the workings of his own mind, because the faculty of perception is not yet developed,
It will possibly be said by some of those who have not quite caught my meaning, that to account for the origin of the perception of relations, I am, by a piece of badly concealed thimble-rigging, introducing into sense-experience that of which I feign to be in search. I first assert that in sense-experience, as such, there is no perception of relations; I pretend to inquire how these relations as objects of perception have arisen; and thereupon proceed to assume that there is in sense-experience a dim " awareness," or " sensing" of those transitions in consciousness which will be eventually perceived as relations; thus slipping the relational pea beneath the thimble of sense experience. I do not think that this would be a just criticism. In any case, I am desirous of laying bare all my assumptions. I assume then that in sense-experience there are impressions and ideas; and that, since sense-experience is continuous, there is also a consciousness of the transitions between these impressions or ideas. Two objects, A and Be are placed before a being in the stage of sense-experience. The eyes are fixed first on one and then on the other. There is an impression of A followed by an impression of B. And these successively occupy the focus of consciousness. But there is also the transition from one to the other, which since it does not in any way interest sense-experience, remains marginal. And this transition it is which, when focussed through reflection, becomes the relation between A and Be the focussing of it being termed the perceiving of the relation. The relation does not become a unit for thought until it is thus perceived or focussed. The distinction is not an easy one to grasp, hut will I trust become clearer as we proceed.
Similarity and dissimilarity are the most generalised 'relations that we know; for objects may resemble or differ from each other in a great variety of respects. if, then, thesq relationships are the expression of the transition id con-
(225) -sciousness from one focal state to another, it would seem likely that all relations between impressions and their ideas are primitively given in consciousness as the transitions from one focal state to another. Such, I believe, is invariably the case. And the transitions in the naive everyday life of practical experience are persistently marginal. In endeavouring to interpret therefore the consciousness of the little child, we may say that the subconscious awareness of relations prior to the advent of perception has its origin in the transitions of consciousness from one focal state to another; and further, that in the unreflective flow of consciousness the transitions are entirely marginal.
Let us now return to our symbolic representation of the sequence of focal states of consciousness, consisting of impressions or their ideas
r - s- n- y - t - v.
It is clear that though we may be aware of the transition, say from r to s, as it occurs, we cannot in the act of passage sense it in its completeness; for in the act of passage the transition is not. yet completed And when it is completed, and s is reached, it is the impression or idea s, and not the transition that led to it, which occupies the 'focus of consciousness. The matter may be put concisely thus :-Every relation involves two related terms ; until the second term is given the relation is incomplete ; but at the moment of passage from the first to the second, the latter is not yet given. Hence it is impossible to sense a relation in its completeness during he transition which is its psychological equivalent.
We have now to consider how we do come to perceive relations in their completeness, and how we obtain definite and clear-cut perceptions of relation. Since it is impossible to get a complete and precise perception of the relation of r to s as the wave of conscious-
(226) -ness is passing from the one to the other, and since it is. necessary for the perception of a relation that both related terms should be given, it is clear that it is only by looking back on the past course of the psychical wave that we can definitely perceive the relationship which was previously only sensed. In other words, the perception of a relation (that is to say, the making of the relation focal) involves introspection, which, as we have already seen, is also retrospection or reflection. If therefore our symbolic illustration
r - s - n - y - t, &c.,
be taken in illustration of the flow of impressions or ideas in sense-experience, the connecting links being marginal in consciousness, the formula may be taken as roughly illustrating the retrospection or reflection necessary for the perception of a relation, or the focussing, as idea, of a transition in consciousness.
It will be well to consider first the perception of a simple space-relation. Let us direct our attention to 'the relation of the point marked a to that marked c.
As we do so, our eyes travel to and fro between the two. First, a is focal, and c marginal' then c is focal, and a mar-
(227) -ginal; and finally, the eye is perhaps fixed on the centre of the vacant space between them, both a and c being marginal.
With the eye thus fixed, the visual impression is that of a -'pair of points ; but if consciousness is focussed on their relation to each other, we have a perception of this relation ;as such. But since the perception is thus directly produced by making the relation focal, and the related terms marginal, where is the justification for saying that the perception of relations involves reflection and retrospection? Remember how the perception of the relation is reached. First a is focussed with c marginal, and then c is focussed with a marginal. Then, and then only, when each related term -has in turn been focal to consciousness, can we make both .marginal, and focus the relation itself. In our diagrammatic scheme r - s - n, r is the impression of a, s the impression of c, and x the transition from the former impression to the latter; and therefore n, as a present and focal state of consciousness, is symbolic of experience gained in preceding moments of consciousness. Moreover,-and this perhaps is the most important feature of the process,-that which is thus symbolised is not any previous impression, but the transition. between impressions. And it is difficult to see how completed transitions in consciousness could be perceived and symbolised without reflection; that is to say, -without looking back upon the past course of the psychical. wave. No doubt the reflection here is only embryonic and germinal. No doubt the process is only incipiently introspective and retrospective. But therein lies its chief interest; for we seem to have here, in the perception of a simple space relation, the first step into a new realm of conscious experience, -- a realm of well-nigh boundless extent.
Let us now extend our 'spatial diagram as under: -
Having perceived the relation of a to c, we transfer our attention to c and b, and proceed to make the relation between them focal just as we did for a and c. Having done so we may proceed a step farther and deal with the group a c b. We then perceive that the relation of a to c is in all respects similar to the relation of c to b. We are here, be it noticed, perceiving a relation between relations and one which involves similarity of distance and similarity of direction. The case is more complex, but it does not involve in it any new order of perception. We are still dealing with a transition in consciousness from one focal state to other, and it makes no difference in principle whether the focal states between which the transition takes place are impressions such as a and c, or perceptions of relation such as a c and c b. In this case in our diagrammatic scheme
r - s - n, r is the relation of a to c, s the relation of .c to b, and n the relation of r to s.
We may now proceed a step farther, and make our figure more complex:--
(229) Let us direct our attention to the relations of d to c and c to e. We soon perceive that the relation of d to c is similar to that between c and e. We repeat, in fact, with respect to the group d c e the experience we gained with the group a c b. But if we take the relation of c a to c d in the group a c d, we find a dissimilarity in the relations, and that I in two respects. For first the distance c d is less than the distance c a ; and secondly, the direction c d is different from the direction ca. The case is again somewhat more complex, but it introduces no new order of perceptions, though it does show that the relations may be definitely perceived to be either (1) similar or (2) dissimilar to each other.
It should be clearly noted that in the perception of relations consciousness is merely dealing in a new way with old materials. Long before we pay attention to, and definitely perceive space relations, -we are marginally subconscious of 'them. We are aware of them, and practically act upon our ,awareness, but we have not learnt the' trick of making them _,focal in consciousness. Nor have we in our early days much need to do so, since marginal awareness amply suffices for all the purposes of practical experience. It is only when we seek to describe things for our neighbours' behoof or for our own satisfaction, that relations are dragged into the focus. Ask a boy of five or six to describe to you how he performs some simple and familiar operation. He will probably want to show you how it is done. But if you meet him with a request to be told, not shown, how it is done, you will probably soon see how puzzled he is. He cannot describe it except in terms of relationships which he has only sensed and not yet perceived. It is not the mete words that he lacks ; it is the ideas which lie in an unfamiliar field. lie has to look back upon his past experience to see how he did it, and he is not much given to such reflection.
Another point that should be noted is that in the case of
(230) space relations we have a definite physiological basis for the feeling of the transition from a to c or from c to d; for the transition in consciousness, when we are dealing with these impressions, is accompanied by (if it be not the psychical expression of) certain definite movements of the organs of vision. When we perceive that the relation of a to c is similar to the relation of c to b, and is dissimilar to the relation of c to d, the physiological basis is to be sought in the similarity of eye-movements in the one case, and the difference both in their amount and in their direction in the other.
Once more it should be noted, that although from the psychologist's or physiologist's standpoint space relations may be explicable in terms of transitions in consciousness or of muscular movements, yet from the point of view of the student of physics they are regarded as frankly objective or external to the percipient. The psychologist, from the nature of his analysis, is bound to regard impressions as states of consciousness, and perceptions of relation as transitions in consciousness. But the physicist in his analysis regards, and is wise in so regarding, both impressions and perceptions of relation as representative (it-is not for him qua physicist to consider how) of external realities. It is a grave error in scientific method to import into a physical discussion of objective motion in space and time a collateral discussion of psychological questions, still more to attempt a statement of the laws of motion for physical purposes in terms of states of consciousness or the transition between them.
We may now pass from relations in space to relations in time. Both Ate alike given, from morning to night, id. the daily routine of experience. But both alike remain marginal until reflection turns the focal light of consciousness upon them. Did the reader notice, as he read what was Said above with regard to space-relations, that time-relations
(231) were lurking throughout in the margin of his consciousness and only needed special attention in retrospection to render them focal ? Yet this is undoubtedly so. The impression of the point a was succeeded by that of c. The time relation was subconsciously sensed, but was not made focal in consciousness. As in the case of space relations, so too with time-relations, although we feel them -as, they pass, yet we cannot definitely perceive them until they have passed. We have in focussing them to look back upon the course of the psychical wave and to fix our attention not upon the impressions as such, not upon the space-relations or the amount and direction of eye-movements in passing from one to another, but upon the sequence or succession. And here, too, it is clear that until the succession a c is completed. We cannot have an accurate perception of the time-relation involved, or in other words it is only by retrospection that such relation can be focussed.
If we represent diagrammatically, in the accompanying
figure, the flow of consciousness from left to right with a narrow focal region, -and on either side of it a marginal region ; then in two succeeding moments of consciousness we have first a focal with c marginal, and then d focal with e marginal. When we are directing our attention to space-relations we make a vertical section of the wave and disregard
(232) the horizontal flow ; and when we are directing our attention to the time-relations we make both vertical and horizontal sections, and perceive a c as simultaneous and a d as successive. It is probable that the psychological and physiological basis of the perception of duration and of sequence is the continuance in consciousness and gradual fading of impressions.' If impressions and the sensation elements which go to the formation of states of consciousness were strictly instantaneous, there could be no continuity of consciousness and no perception of duration or of sequence. But impressions do not appear and disappear in consciousness instantaneously. They take an appreciable time to fade out of consciousness. If two notes in succession be played or struck on a musical instrument, the first remains marginal in consciousness when ;he second has come in to occupy the focus. The sound as a psychical experience does not cease abruptly, but gently dies away; and such fading of impressions probably affords the subconscious material of our awareness of duration and succession, and of our subsequent perception of relations in time. And' here it is worth noting that our accurate measurement of, and symbolization of time-relations, is through the intervention of perceived relations in space, -- the space passed over by the hands of our clocks, the space covered by the movements of the heavenly bodies, or the shadow on a sundial, and so forth.
The raw materials of numerical relations, as of those of space and time, are given in our daily experience, and are marginally sensed long before they are focally perceived. The child, long before he can count, senses the difference between one thing and two things, between two and three, between three and several, between several and many. It would not be surprising to find that a clever dog was able to distinguish from each other playing-cards, from the ace to
(233) the ten. But they would be distinguished through difference of sense-impression, not through pcr~eption of numerical relations. So, too, with succession. One can very readily distinguish a succession of three from a succession of four, without anything like counting, through the sensing of senseexperience. It is, indeed, surprising how large a group of sounds, up to sixty-four in my own case, can be appreciated as a group without counting. But the perception of numerical relations is something more than the sensing of a group of discrete objects or sounds. It is also to be distinguished from the perception of the group as larger or smaller. Whether the numerical relations were first perceived among objects simultaneously presented, or in 'association with succession, we cannot say; but it is at least possible, if not probable, that they arose in close association with that phase of time-experience which presents us with succession rather her than with duration. Run the eye slowly from left to right along the shaded diagram (Fig. 17). You
are subconsciously aware of the duration of the impression it produces. But if you run the eye along the second figure (Fig. 18), you are aware of succession. The homogeneous
duration of a continuous impression gives place to a successive series of similar impressions. And in this series you
(234) have, not only one aspect of time-sequence, but also the material from which a numerical sequence may, on the advent of reflection, be evolved.
We have already seen that when the attention is transferred from a red wafer to another red wafer, or from a red one to a blue one, we are subconsciously aware of the similarity or the dissimilarity of the transition in consciousness. For purposes of daily intercourse, and for purposes of physical science, we should speak of the similarity of the red wafers to each other, or of the dissimilarity of the red to the blue. That is to say, we should attach the similarity to the object. But for purposes of psychological analysis we regard the matter from a different standpoint, The red wafer of the plain man or the physicist is for the psychologist a substantive impression, and the similarity of the two red wafers, or the dissimilarity of a red and a blue one, is a transition in consciousness. So long as this transition is only subconsciously sensed, we have merely a dim awareness of the similarity or dissimilarity ; but, when the transition is rendered focal, we have a clear perception of the relation. And, as in other cases, this perception involves reflection. To perceive the relation between the white and the shaded disc in Fig. 19, we fix the attention first on one and then on
the other, so as to make first the white focal with the dark marginal, and then the dark focal with the white marginal. We may then make both discs marginal, and fix the atten-
(235) -tion on their similarity- of size or their dissimilarity in shading, thus rendering, not the discs themselves, but theirrelation in particular respects, focal to consciousness.
In perceiving such relations there is no necessity that there should be eye-movement. If by means of a lantern a red disc is thrown on a screen, and then the red be suddenly changed to blue, we can perceive the colour-relation, or the transition in consciousness from one to the other. Or, to take the testimony of other senses, we can perceive the similarity or dissimilarity of two succeeding sounds, or of two tastes or scents, or pressures) and so forth. The physiology of these transitions is not well understood; but the similarity or dissimilarity is presumably between like or unlike cortical conditions. Psychologically, what we call a perception of similarity is therefore a recognition, through retrospection, that two succeeding impressions were in certain respects identical, or that the transition was from like to like; while dissimilarity is the perception of a difference in the subsequent impression, or that the transition was from like to unlike. There must be, a transition for the perception of similarity or dissimilarity. If there be no transition, we do not speak of the similarity of two impressions, but the continued duration of a single impression. in any case, the essential point to notice is that the definite perception of similarity involves the conscious and focal appreciation of the relation of likeness as such, and differs from the mere subconsciousness or marginal awareness that an impression is one that has occurred before in previous experience. Throw a street urchin a halfpenny, or a dog a piece of biscuit They do not stop to render focal the similarity of the objects to previous halfpennies or previous bits of biscuit. The one goes for the focal halfpenny; the other for the focal biscuit. Their actions show that they are aware of the likeness of these impressions to previous impressions; but they show no evidence of making the relation focal. If
(236) We say that the dog recognizes the object as a bit of biscuit, we must be careful to distinguish between this simple and elementary form of recognition, and that higher. form which implies a conscious perception of the relationships involved. The one is at most a subconscious awareness that the impression is not new or is familiar; the other is a fully conscious product of reflective thought. The one is the outcome of sense-experience; the other is a bit of intellectual knowledge.
Let us here note an important gain to the mental life which is incidental to and the outcome of this process of the perception of relations. As we compare with each other the objects presented in sense-experience, rendering focal this or that relationship which obtains between them, we are inevitably forced to pay special attention to those attributes or qualities in which the relationship specially holds good. If we are comparing objects with respect to their size, their weight, their hardness, their colour, or any other quality or attribute they may possess, and if we, are focussing the relation in this particular respect, such quality is necessarily emphasized at the expense of others with which it is closely linked in sense-experience. It is thus rendered predominant over the others, and is oil the high road to become the abstract idea of intellectual thought. Nor can the process of comparison and the perception of the particular relations between concrete objects of experience be carried far, if indeed it can be carried on at all, without a dawning conception of the universal validity of the relationships dealt with in particular instances. Thus the perception of relations forms the starting-point of the higher intellectual operations which lie in the sphere of conceptual thought as it is developed in mankind. We shall hereafter have occasion to consider some of the characteristics of conceptual thought. It is here only necessary to observe that its foundations are laid in the perception of those relations which in it reach explicit abstractness and universality.
We must now proceed to note that when once the perception of relations' has entered into the fabric of the mental synthesis, its results become woven through and through the tapestry of consciousness, so as to constitute an abiding background. When once relations of space, time, number, size, and so forth, have been perceived, representative perceptions may be called up by association, not necessarily into prominence, but into the marginal background of consciousness. The sportsman's recognition of the partridge lie brings down is different from the dog's recognition, because for the sportsman there is a subconscious background of relationships which have been perceived, while for the dog this subconscious background is, as I believe, absent. This suffusion of all our impressions with more or less of a definitely relational tone, is what raises them to the level of percepts. For, as I before said, the percept is an impression to which is added a conscious or subconscious perception of relation to the subject or to other objects ; or, as we may otherwise phrase it, the percept is an impression set in a relational background. In previous chapters we have intentionally neglected or endeavoured to eliminate all that differentiates the impression from the percept. Now it is necessary to introduce this factor in the mental synthesis, a factor which is, as I believe, distinctively human. Animals and little children live in a world of impressions and ideas, set in a background of dimly-sensed relations which have never been perceived as such. For fully developed man the world is a world of percepts, set in a background of relations which have been consciously grasped. It will be noted, however,' that it is not the focal impression itself but its marginal setting which is thus modified. And since we can, in analytic thought, dissociate the impression from its setting, we may perhaps fairly, hope that what we have already endeavoured to establish concerning impressions, in sense-experience or consentience, is nowise invalidated by
(238) the fact that in us the setting is different from that which forms the subconscious background in the infant and, as I shall hereafter more definitely suggest, in the animal.
We will take one more example of a relation, the definite perception of which differs markedly from the marginal awareness which is its precursor in mental development; and this relation we may term that of association. There are a thousand and one occurrences in our daily life which afford a basis in experience for the perception of such a relation. Numberless events are associated with definite consequences. The occurrence of any one of these begets a feeling of expectation of that which is its normal associate. The child sees a sweet, and as he stretches out his hand for it there rises in his mind, through association, an idea of its taste. The taste is suggested by the visual impression, and we say that the two are associated; but for. the child there need not be, and probably is not, any perception of the association. The daily life of many of the lower animals is moulded by certain practically constant associations in experience; thus it is they obtain food, thus they avoid danger. But there is no reason to suppose that they can or do perceive these associations as such. Relationships, even the most constant-those by which experience is continually guided-are beyond them, because it is only through reflection that the relationship can be perceived. The most that we can say is, that through sense-experience they are dimly and subconsciously aware of these constant associations. They sense where they cannot perceive.
Enough hag now been said in elucidation of the distinction between the focal perception of relations and the mere marginal awareness of the transitions in consciousness from impression to impression. It is of the essence of experience as given in our daily life that substantive impressions stand out like clear-cut figures in the midst of a number of more or less dim and shadowy spectres in the marginal region of
(239) the conscious field. And it is just because there is in consciousness not only a focus but also a margin, any spectre in which may subsequently become a focal and clear-cut figure, that we sense or are aware of the relations which the figures and spectres bear to each other. So long as our interest is centred in the figures themselves, their relations to each other are merely incidental. But if we wish to describe the conscious scene, then we are forced to bring the relation-ships into focal prominence. No description, still less any explanation or knowledge, properly so-called, is possible, except in terms of the relations which the figures, and spectres bear to each other. To describe,. to explain, to understand a scene, one has to dwell upon it reflectively and note the relations which its several parts bear to each other.' Try to describe the simplest visual scene, or a commonplace sequence of events, and see if you can do so without using words which render focal the relationships involved. An infant or a dog cannot understand the simplest possible description, because the words which stand for the relationships have no meaning. The words which stand for impressions may have suggestive value. The word "cat " or it rats" may have for the dog a very definite suggestive value ; and hence some people fancy that when they say to their dog " there is a cat in the garden," the animal understands what they say. But there is no evidence that the dog understands. It is quite sufficient to suppose that the word " cat " has suggestive force, all the rest being for the dog mere surplusage of sound. Those who have had experience in teaching tricks to dogs or other clever animals will be well aware how futile it is to describe or explain what they are to do. We will not, however, pursue further at present the bearing on animal psychology of what we have learnt in this chapter. But the fact that we cannot describe, still less explain, without rendering the relationships explicit and focal, justifies the suggestion that the perception of
(240) relationship, rendered possible by reflection or retrospection, was, in the evolution of man, rendered necessary for the purposes of social communication.
The mode of origin of the perception of relations, is admittedly one of the most difficult steps in psychological development to explain and render probable from the evolution standpoint. The explanation here offered does not lay claim to be in all respects adequate and complete. But I believe it is on the right lines. In the simplest experiences of daily life there are given what we may term, by anticipation, space-relations and time-relations, and arising out of these, relations of size or extent of space-occupancy and of duration or extent of time-occupancy ; numerical relations and relations of normal association ; relations of colour, tone, and illumination among visual objects ; of pitch, intensity, and timbre among sounds ; of sweet and bitter among tastes ; of pungent, aromatic, and so forth, among scents; of varying pressure and temperature, and all the other differences, among sense-data ; and in the midst of all these, relations of similarity and dissimilarity. All of these, and, as life becomes more complex, other less simple relationships are given, and may eventually, in the course of mental development, be perceived. And my object has been to show that, as primarily given in unreflective sense-experience, they remain marginal in consciousness, but that eventually they may become focal through the perception of relations.