An Introduction to Comparative Psychology
Chapter 4: Suggestion and Association
C. Lloyd Morgan
WE must now return to the wave of consciousness, with a brief consideration of the nature of which we began our investigations. We saw that in any moment of consciousness-any particular now-it is experienced as a complex whole, which only on introspection and retrospective analysis can be resolved into its constituents. Let us next consider by what means and in what manner the nature and constitution of the wave is brought about or determined in any series of successive moments of consciousness. In this chapter we shall deal mainly with the wave-crest or focus of consciousness, to the partial neglect of the subconscious body of the wave.
When we take a walk in the country and wisely surrender ourselves to the suggestions of rural nature, the wave crest of consciousness is mainly determined by sights and sounds and scents coming from without. When on our return we sit and read some book with attention, the nature and course of the psychical wave-crest is determined by what the author has written for our instruction or amusement. Or if we listen to our friend describing what be has seen or done in our absence, the course of the wave is guided by his words. In all these vases the determination of the nature of the wave-crest is largely external; but in the first case tile external suggestion comes directly from the natural object while in the latter cases the external suggestion is indirect: through the intervention of symbolic means. For language, written or spoken-, is the medium by which we can
(60) tender the wave of consciousness in our neighbour's mind somewhat similar to that which is passing or has passed through our own.
When, on the other hand, we abandon ourselves to a train of reverie, with closed eyes in a quiet half-hour, or when we are abstractedly thinking out some problem, and are deaf to all that passes around us, then the nature of the wave is not determined from without, but is of internal origin.
But what exactly do we mean when we speak of the determination of the wave as "external" or "internal"? Has the mind, as such, extension or place, so as to justify the use of these physical expressions? Assuredly it has not: and in using the terms 11 external " and " internal " we have momentarily changed our point of view from that of psychical processes to that of their physical accompaniments. The psychical wave accompanies or is the conscious aspect of the dominant cerebral disturbances in the cortex of the brain. Now the dominance of cerebral disturbances at any moment may be produced in one of two ways, or in part by one and in part by the other. Such dominance may be determined by incoming stimuli through the afferent nerves ; this is external determination. Or it may be determined by the preceding cerebral changes, the brain-states of any one moment being the outcome of the brain-states of foregoing moments; this is internal determination. The terms " internal " and 11 external " are thus, strictly speaking, applicable to the cerebral cortex, which is the seat of molecular disturbances, accompanied by states of -consciousness. Where these dominant disturbances are the result of preceding disturbances within the cortex, the determination is internal; where they result from afferent impulses coming from beyond the region of the cortex, the determination is external.
It must be noticed, however, that all the external stimulus does is to set agoing certain Internal processes, The im-
(62) -pulse from without is like the touch of the trigger -which determines a complex explosion,. When we are out for a country walk light-waves received by the retina of the eye originate impulses which, conveyed inwards by the afferent nerves, initiate brain-disturbances having for their conscious aspect fields and woods, streams, birds and- insects, and so forth. We say that we see all these ; and we speak correctly. But in the language of psychological analysis we receive sense-stimuli which suggest all these impressions and certain ideas arising out of them to the mind. Certain notes or sounds suggest the thrush, the cuckoo, or the grasshopper certain odours, violets or limes.
When we are reading or listening to a speech, states of consciousness are evoked by the printed words (retinal stimuli) or by the sounds which fall -on our ear (auditory stimuli). The suggestion of the states of consciousness is external. But the nature of the states depends upon the internal conditions and organization of the brain-centres We may term the initiation of states of consciousness by external stimuli primary suggestion, reserving the phrase secondary suggestion for the wholly internal determination of states of consciousness by changes within the cortex.
Taking primary suggestion first, we are not at present in a position to analyse the process very deeply, and must defer its fuller consideration till we come to the chapter on The 'Analysis of Impressions. I shall describe as an impression that which is brought to the focus of consciousness, or to the crest of the psychical wave, through primary suggestion. And for the present it must be sufficient to note that the nature of the impression thus suggested -by a simple stimulus or by several simple stimuli, is determined (1) by inherited brain-structure or its psychical. correlative mental constitution (2) by the modification impressed on this brain-structure or mental constitution by individual experience. In brief, the exist-
(63) -ing condition and mode of response of the brain is due in part to inherited structure and in part to individual acquisition. So far as the impressions are concerned, that is to say the focal states suggested by simple afferent stimuli, these impressions are presumably very similar or practically identical in all normally constituted human beings. My friend and I have closely similar impressions of the road along which we are walking, of the hedge that borders it, of our dogs racing on in front of us, of the setting sun and the deeply-tinted clouds on the horizon. It is true that no two of us taking the same me country walk will have quite the same states of consciousness aroused by external suggestion, because no two of us have had quite the same individual experience, and in no two of us is the mental constitution and inherited brain-structure identical. But the difference here lies not so much in the impressions, or focal states, as in the marginal states which form the body of the psychical I wave. Thus, although the impressions are closely similar, the states of consciousness, which include not only the focal impressions but also their marginal setting, are different.
As my friend and I are walking along the road, during a pause in our conversation we pass a gate at which some -cattle are standing. We both begin to speak at once, and, after mutual apologies and the usual courtesies, he takes the precedence, and tells me of the Red Devons with which he has stocked a farm which lie has lately purchased. When he has spoken, he asks me what I was about to say ; and I laughingly reply that I was merely going to -ask whether he thought certain recent promises to electors (1892) were much more likely to be fulfilled than certain other promises in 1885 concerning three acres and -a cow. Now here a similar impression, the result of primary suggestion) gives rise in two different minds to two different trains of ideas.
Before going further we must define what is here meant by the word" idea." We used the word "impression" to
(64) signify that which is brought to the focus of consciousness, or the crest of the psychical wave, through primary suggestion. We shall use the word "idea" to signify that which' is brought to the focus of consciousness through secondary suggestion. The idea may be a clear-cut mental image, like the remembered face of a dear friend, or it may be as vague as that which attaches to the word " universe" or the word " fog." Whether well or ill-defined, it occupies the crest of the psychical. wave and has been brought there, not by primary suggestion through the channels of sense, but by secondary suggestion -as the result of foregoing brain-disturbances. Thus the primary impression cow gives rise in my friend's mind to the secondary idea farm, and in my mind to the secondary idea " elections." These ideas may suggest others, and so on in a longer or shorter train of secondary suggestion.
It is somewhat difficult to assign exactly the limits which demarcate primary from secondary suggestion. If, for example, I see on Exmoor a footprint which suggests a red-deer; shall we say that the impression is that of a footprint which in turn gives rise to the idea symbolized by the word " red-deer " ? or shall we say that an impression of a reddeer is primarily suggested ? In this case we may perhaps fairly adopt the former view, and say that the footprint suggests the idea of the beast that made it. But if I see over the brow of the hill the points of an antler, shall we say that the impression of a bit of an antler suggests the idea of the stag that bears it ? or shall we say that the visual stimulus from a portion of the stag suggests the impression of the reddeer ? Let us suppose we still adopt the former view and say that the impression of an antler-point suggests an idea of the stag. Then how will it be if I see the head and shoulders-, while the legs and hind-quarters are hidden ? Surely here we may fairly say that we have a direct impression of the red-deer. If so, we imply that a small
(65) portion of the stag suggests an impression which gives rise to an idea-of the animal itself, while a larger portion directly suggests an impression of the animal. I have no desire to be over-subtle, and I think it probable that if two men -- one an experienced and enthusiastic staghunter, the other a mere townsman-were standing to-ether on Exmoor and saw the points of an antler ; in the one case red-deer would shoot to the focus of consciousness as a practically direct impression while in the other a vague " something visible " would slowly take form as an impression, to be gradually followed by an idea of the animal, with some such train as this : " Why, it must be an antler; a red-deer, by Jove." These cases, and a hundred other such, show that the demarcation between primary and secondary suggestion is not very easy to draw with strict rigidity.
If we adopt this interpretation, however, we must admit that the impression may contain a greater or less amount of ideal supplement. Only the antler-tip is presented to sense: the rest is ideally added.
Returning now to the case above noticed, where the same impression cow gave rise for me and for my friend to different trains of ideas, there is not much difficulty in assigning, in general terms, reasons for the different results in his mind and in mine. His farm in Devonshire had been for some time a topic of thought and discussion, his mind had a constant tendency to revert to this subject. Presumably from the physiological point of view certain cortical centres, the disturbances in which are associated with this particular form of consciousness, were already in a state of irritability or incipient change, and only needed a suggestive impulse to raise their molecular thrills into dominance. Probably the farm was lurking in the background of hip consciousness as lie walked silently by my side. On the other hand, my own mind was, as we say, full of the elections, and of certain statements reported to have been made in
(66) Wiltshire to catch the agricultural vote. The cow appeared to me therefore in an electioneering connection. Had a butcher been with us, the cattle might well have suggested the peculiar excellence of last year's Christmas beef. Or if a student of pre-historic archaeology had been there, his mind, through the intervention of Bos primigenius, might have wandered to the Europe of primitive times.
All this serves to bring into view what appears to be of great importance in serving to determine the direction of the course taken by the psychical wave in secondary suggestion, namely- immediate interest. There are certain permanent interests concerning our own future, that of those near and dear to us, that of our own past Work, that of our business or occupation, that of our favourite schemes. All these are more or less directly associated with ourselves. In each moment of consciousness they do form or may readily be caused to form part of the body of the wave. They are constantly either in or near the margin \of consciousness. There are also the more transitory interests of our immediate thought or occupation, the game we are playing, the book we are reading, the problem we are thinking out. These, too, form important constituentsthe psychical wave in the moment in question. If we call the former general interest, and the latter special interest, we may say that the course of the wave, in secondary suggestion, is largely determined by the joint action of general and special interest. Although in a less degree interest has some effect in primary suggestion. Every-one knows the story of Eyes and No-eyes. Interest largely makes the difference between the two. If a naturalist is out for a country walk with one whose absorbing pursuit is abstract mathematics, the former will hear and see much to which the latter is psychically deaf and blind. The retina and the auditory nerve-ends are stimulated, but the subconscious effect produced has no chance of rising into dominance
(67) when it has to compete with a matter of such absorbing interest as a problem in four-dimensional space.
The course of the psychical wave, then, is largely determined by interest ; and the interests of our life are constantly lurking in the margin of consciousness. They ,form a sort of permanent body to the psychical wave. In saying, therefore, that the wave is largely guided in its course by interest, we are saying in effect that in any series of moments of consciousness a b c d, the state of the wave at c is determined by the state of the wave at b, and will in urn determine the state of the wave at d. In other words, the interest is internal, and something the wave carries with it; not external, and moulding the wave of consciousness from without. The only qualification of this general statement we should have on deeper analysis to make, is that probably not only the subconscious states of the body of the wave, but also various infra-conscious or extra-marginal elements below the threshold of consciousness, would have to be taken into consideration. We are burdened, for example, with a great sorrow, but have to fulfil an engagement to lecture or make a speech. Beginning with an effort, we erelong get 'interested; thoughts connected with our purpose in speaking occupy consciousness; our sorrow for the time is forgotten. We walk away animated perhaps with success ; but from out of the unconscious there rises a numb and nameless feeling, and our sorrow regains its sway. It has in the excitement of speaking. been thrust below the threshold of consciousness out into the extramarginal region. But no sooner does the excitement subside, than it rises first into numbing subconsciousness, and then with a pang becomes dominant and focal.
Returning once more to the example we have taken to illustrate secondary suggestion, it is clear that the impression caw would never have suggested farm to my friend's mind, nor " elections " to my mind, in the absence of previous
(68) experience. Internal or secondary suggestion does -but follow lines previously marked out by external or primary suggestion. A London child visiting the country, and seeing for the first time the yellow flowers of the gorse or furze, is told ]low Linnaeus, the great botanist, when he first saw a furze-hush in golden blossom, knelt down and thanked God that, he had been permitted to see such a sight. Certain states of consciousness are thus directly suggested by the sight of the flower and the telling of the incident. Subsequently the sight of the furze-blossom will recall the story of the incident to the child's mind. The wave of consciousness will tend to repeat its former course. Not only the story of the incident, but its narrator, and the whole scene, will be more or less clearly suggested. And then the idea of the narrator will perhaps remind the child of another incident she told on the same occasion concerning Charles 11. in the oak-tree; and this again will call to mind the history lesson that has to be learnt for to-morrow; and so on.
The wave of consciousness, then, in secondary suggestion tends to repeat its former course, that which was determined by the primary suggestion of direct experience. Tile occurrence of two impressions in immediate sequence establishes a link between them ; and the subsequent occurrence of the first impression suggests the idea which answers to the second. The name given to this link is association. The sight of furze-blossom, and the story of Linnaeus, are associated in primary experience; and the subsequent sight of yellow furze suggests the story by association. But though the wave of consciousness in secondary suggestion tends to repeat its course, it only does so imperfectly, and for a short distance. It is at any moment liable to be switched off in a new direction, owing to the influence of a stronger association. Thus the sequence in the child's mind when he again sees the yellow
(69) furze is,-Linnaeus: narrator: oak: English history: tomorrow's lesson. This is not by any means all accurate ,reproduction of any one previous sequence, but is made up of bits of several previous sequences.
It is clear that in the case of all common objects of which we have had direct experience under varying circumstances, and in the case of many common words which we have used in numerous connections, there is not one particular line of association with each, but rather a number of divergent lines. Indeed, the associations with each familiar sight and sound, and each familiar word, are so numerous and so divergent, that they have, in adult life, little tendency to direct the course of the wave of consciousness in any particular direction. It would be, exceedingly inconvenient if they had. If each predicative word in a sentence tended to switch off the wave of consciousness on some particular .line of its own, we should lose ourselves in the maze of side issues. If " lose" necessarily reminded us of some particular game, or sum of money we had lost; if "maze" sent us off to wander in memory between thickset hedges at Hampton Court; if "issues" led us in thought to some ,spring where the water issues from the earth ;-how confused would be the result of reading the latter half of the last sentence. And no doubt this is one of the difficulties of early education, and one of the causes of the apparent inattention of children. Experience being limited, the words have particular associations which divert the attention from the subject-matter in hand.
Divergent association is therefore a great gain. For since of the many possible diverging lines there is no inherent tendency to follow any particular one, tile mind hangs poised, following none, but ready to follow any of them. But how it, if this be so, that in reading a paragraph each word helps to carry the mind -- for at each moment of consciousness the existing phase -of the psychical wave is
(70) for empirical psychology the mind-along the special line intended by the author ? If each word has divergent associations, how is the particular association intended by the writer suggested ? On the principles already laid down the answer to this question is not far to seek. The word does not stand alone in the paragraph, and that which it suggests is only part of the psychical wave. -The moment of consciousness embraces not only the particular word in the focus, but a few words that have not reached the focus, and half a sentence or more that has passed the focus and is fading out of marginal consciousness. And since the psychical wave in succeeding moments of consciousness is continuous, it is determined at any one moment by what it has been at previous moments. When we are reading any particular word, what it suggests is determined by the net result of all the preceding sentences in the paragraph.
In like manner, if in a chain of reverie any particular idea or image occurs, what it will serve to suggest depends upon the nature of the psychical wave as a whole, of which this image or idea, though for the moment in the focus, is only one constituent element out of several or many. Much confusion arises, and many unnecessary difficulties present themselves, if we fall into the analyst's fallacy and suppose that the particular idea or image, which we can separate from the rest by retrospective analysis, was separate and distinct from the rest in its natural occurrence. Therefore I again insist on the fact that in the moment of consciousness the psychical wave has numerous elements; and that a state of consciousness is something exceedingly complex, and vciy different from an isolated image or idea.
So complex is each state of consciousness -- that is to say, the psychical wave in each moment of consciousness-that the same state of consciousness probably rarely occurs twice in the experience of any individual. Even when the central impression or idea is the same, its setting, the marginal
(71) region or sub-conscious body of the wave, is different, Our surroundings are not quite the same. We ourselves change from day to day and from year to year. The continuous individuality-that felt bond of continuity in conscious existence-is, be it never so slightly, modified by all our experiences, We feel that we are not what we were. The psychical wave at any moment of consciousness leaves traces or habitudes which modify all future phases of the wave. If then a state of consciousness is so complex, and if it is rare that any two states of consciousness should be quite the same, it might seem a hopeless task to endeavour to formulate the laws which condition their being. But here, as in other matters of science, we employ the method of analysis, and, by studying- severally, through retrospection, the constituents of the psychical wave, obtain some insight into its constitution and the manner of its origin.
As the result of such analysis certain laws of association have been formulated. As generally accepted they are two -(1) association by contiguity, and (2) association by similarity; to which, as subsidiary, is sometimes added a third, (3) association by contrast.
The law of contiguity may, in accordance with our method of presenting the subject, be thus enunciated :-If any two focal states a and I occur in successive moments of consciousness as impressions, the subsequent recurrence of a as impression or idea will tend, under similar marginal conditions, to suggest the recurrence of I as: an idea.
In primitive experience the focal states a and I are determined by primary suggestion, and both are therefore impressions. Thus a vivid Hash of lightning is followed in normal experience by a thunder clap. lit the absence of experience there is nothing in tile former to suggest the occurrence of the latter. Subsequently the impression of lightning will be followed by an idea of a thunder-clap, and this idea will very probably precede the actual impression,
(72) constituting what is sometimes called a pre-perception. Eventually the idea of a flash of lightning, however produced, will be succeeded by an idea of the thunder-clap. A lady of my acquaintance once told me how, after a storm, she showed her little boy a spirited picture of a storm at sea with a ship being struck by lightning. He gazed intently for a few moments and then asked, " Mother, why doesn't it rumble?" The law of contiguity, be it noted, says nothing about the primitive sequence a 1; that is given in experience. The sequence may be a natural or an arbitrary one; with this the law of association has no concern. it only asserts that if a be followed in experience by 1, then subsequently the recurrence of a, either as impression or idea, will be followed by the recurrence of I as an idea.
It may be well to note here the limiting conditions introduced in the foregoing enunciation of the law of contiguity. The recurrence of a will be followed by the recurrence of I under similar marginal conditions. We have already seen how the impression cow suggested farm, &c., to my friend, and "elections," &c., to me. The marginal conditions, the settings, so to speak, of the impression, were different in the two cases, and the secondary suggestion was therefore different. Only under similar marginal conditions, will the impression a suggest 4 Under different marginal conditions, it may suggest P or z. It is true that the, marginal conditions never or very rarely are quite similar. But such an assumption in the enunciation of a general law is very common in scientific method. The first law of motion asserts that the motion of a body when left to itself will be uniform and rectilinear. Practically no physical body is left to itself; it is never free from the influence of surroundings. But no one with an- adequate grasp of scientific. method regards this as a defect in Newton's law.Nor should we regard the assumption of similar marginal conditions as any defect in the law of contiguity.
It must not be supposed, however, that the law of contiguity is on the same plane of universality as the first law of motion. There is another implied but unexpressed assumption that is never more than partially true. It is assumed that memory is perfect. That this assumption is false, or only partially true, is only too apparent. We may to-day establish the sequence iter itineris, or seven-times-eight fifty-six, in a small boy's mind, so that at the end of the lesson iter at once suggests itineris, and the multiplication-table runs smoothly. But next week iter unfortunately does not. suggest itineris, and the multiplication-table is decidedly lumpy. Those of us who in adult life have weak or treacherous memories, know well that associations are often not permanent but transitory. The wave of consciousness that flowed so glibly from a to I last week, now flows to any other letter of the alphabet. The bond between a and I seems to have dissolved. It would be confusing, however, to interpolate in the midst of a consideration of association more than a passing allusion to the conditions of memory.. It is therefore sufficient to note here that the relative permanence or transiency of association-links is primarily dependent on unalterable physiological conditions. Macaulay could not help remembering; most of us cannot -help forgetting. Secondly, with a given faculty, the relative permanence depends (1) on the strength of the initial association depending largely on the interest it arouses; (2) on the recency of its establishment; and (3) on the frequency of its occurrence. For the present, however, we neglect all these considerations and assume a perfect memory, though, as we shall hereafter see, forgetfulness is one of the conditions of our mental life, and a sine qua non of its development.
We are still very far from anything like adequate or exact knowledge of the physiological conditions of association external stimulus x, giving rise to the impression a, is
(74) followed by a quite unconnected stimulus, y giving rise to the impression I At first sight there is no obvious reason why any connection should be-established between a and I And if the stream of consciousness were discontinuous, there would be no psychological connection. Assuming the continuity of this stream, we may diagrammatically represent the effects of successive stimuli, thus: --
The dotted line represents the flow of the stream of consciousness. The stimulus x gives rise to the impression a, and the subsequent stimulus y to the impression l. There is no direct connection between a and l; but there are indirect connections in the transitional occurrences within the stream of consciousness between these impressions.
But we, may regard Fig. 10 as a physiological diagram. The dotted line then represents the stream of occurrences in the nerve-tissues of the brain, in which a and I are externally determined by stimuli. The connection then lies in nerve impulses along interconnecting nerve-tracts between the centres concerned in a and I respectively. There is no reason to suppose, however, that these interconnecting nerve-impulses have conscious accompaniments. The continuity is purely physical or physiological. Only on the assumption that the diagram represents the stream of things in themselves, the realities underlying physical and psychical appearances, can we satisfactorily predicate continuity. This no doubt introduces metaphysical conceptions. But they are inevitable.
To return to the law of contiguity. We have seen that, as above enunciated, it asserts that if any two focal states a and
(75) l occur in successive moments of consciousness, the subsequent recurrence of a will tend, under similar marginal conditions, to suggest the recurrence of l. As it is frequently stated, however, the law of contiguity seems to assert something more than this. It asserts that either of two ideas associated by contiguity tends to suggest the other. And this as a practical fact is sufficiently conformable with experience. I notice, for example, in my country walk an unfamiliar shrub, and then its peculiar lanceolate leaf Afterwards the sight of the shrub suggests the leaf, and conversely the sight of the leaf will suggest the shrub.
Let us note in passing, that although the leaf is part of the shrub as a natural object, yet the leaf and the shrub are quite distinct as impressions or ideas. When I have an impression of the shrub, it occupies the focus of consciousness as a whole; but when I concentrate my attention upon one particular leaf, the shrub, though still present to consciousness becomes merely marginal. I may have an impression (or an idea) of a flock of sheep, of one sheep of the flock, of a portion of the fleece of one sheep, or of one hair of the fleecy wool. All of these are quite separate ideas, which may occupy the focus of consciousness in successive moments, and are capable of becoming associated by contiguity. As the bush may suggest the leaf, so may the flock suggest the individual sheep, and in each case it would seem that 'the order is reversible. It would seem then that we must modify our previous statement, and assert th at the psychical wave may either repeat- its previous course, a being followed by l, or reverse its course, l being followed by a.
I question, however, whether the wave ever does reverse its course. The story is told of a schoolmaster who asked a sailor lad to box the compass backwards.- He readily did so; and then asked the schoolmaster to say with equal rapidity the alphabet backwards. He could not. For the
(76) sailor lad, the wave of consciousness had been wont to flow round the compass in either direction indifferently ; for the schoolmaster,' the wave of consciousness had always flowed in one direction, and he could not reverse its course.
In the many cases where either of two ideas will indifferently suggest the other, as in the case of the shrub and_ its leaf, it is probable that there has been an alternate occupancy of the focus of consciousness. Shrub, leaf, shrub again, leaf again, and so on. Either will then suggest the other, the wave repeating a part of its former course with- out reversal. In any case it does not seem in accordance with experience to say that the order of suggestion is in all cases indifferent. Many of us who have a fair reading acquaintance with French or German, speaking it or writing it but seldom, find that though the foreign word, at once suggests its English equivalent, the English word does not at once suggest its French or German equivalent. But if we have a conversational. knowledge of the language as well as a reading knowledge, this difference disappears. The order of association is here-in my own case at all events-not indifferent. I think we may therefore leave the enunciation of the law of contiguity as above given, requesting those who are satisfied that reversal is also true to modify the statement of the law in accordance with this view.
Passing now to the law of association by similarity, we find that this is not so definite and clear-cut, or so general in its application, as that we have already considered. It may be thus stated :-If two focal states of consciousness resemble each other, the recurrence of the one as impression or idea will tend to suggest the recurrence of the other as an idea. Note the ambiguity of the word " resemble." If we ask: Resemble in what respect? we can only reply: Resemble sufficiently in any respect. But we shall find it hard to render definite the sufficiency of resemblance. We
(77) may express the law somewhat differently thus :-If two focal states have common elements, the recurrence of one of them will suggest the recurrence of the other. But we cannot define very clearly what either the nature or the amount of the common elements must be to ensure recurrence under the law of similarity.
Standing by the medallion of Wordsworth in Grasmere church, my companion said to me, "It reminds me of Dante." Something about the face, perhaps the nose, suggested that of Dante. When associations of this type occur, we generally express them by some such phrase as "This reminds me of that," or "This resembles that." The crocodile reminds us of an alligator; the slowworm resembles a snake. Instances of such association are so common and familiar that they need no further illustration.
I shall employ the phrase association by resemblance for such cases as these where an impression suggests the idea of that which more or less closely resembles it, and shall use the phrase association by perceived similarity of relationship for certain more complex cases of far wider range and of a far subtler nature. These cases I will now proceed to illustrate.
Where Shelley says, in his " Ode to the West Wind":
"Drive my dead thoughts over the universe
Like withered leave.,, to quicken a new birth,--
the similarity between the focal idea " dead thoughts " and the focal idea " withered leaves " is by no means simple and obvious. One may say indeed that there is no similarity between the focal ideas taken by themselves ; they are only assimilated through the imaginative insight of the poet. The metaphors and imagery of every great poet are full of such subtle associations. Take, for example, Shakespeare's
Now is the winter of our discontent
Made glorious summer by this sun of York."
Keats speaks of wine in a goblet,
"With beaded bubbles winking at the brim."
Tennyson, in " Akbar's Dream," writes:
Has lifted the dark eyelash of the Night
From off the rosy cheek of waking Day."
The slow prosaic mind cannot follow these subtle associations, involving delicate perceptions of similarity of relationship, that abound in and give character to the best imaginative poetry. It wonders why Shakespeare drags in a reference to the season of the year, and thinks he should have spelt sun of York with an o. And when Keats, with his subtle and imaginative play of thought, says that Porphyro
" From the closet crept,
Noiseless as fear in a wide wilderness;
or when Browning, who had so thoroughly assimilated certain salient scientific truths, says
"And I know not if, save in this, such gift be allowed to man
That out of three sounds he frame, not a fourth sound, but a star;"
many complain of their similes as far-fetched. And probably no one who had not a permeating knowledge of the fact that the white light of -the star is resolvable into differently coloured rays, would catch Browning's thought that just as different colours combine to form white light, symbolized concretely in "a star," so do different sounds coalesce to form that new and diverse experience -a musical chord.
Wit and humour largely depend upon association by similarity, as where Oliver Wendell Holmes writes, the street-band having ceased its torture : --
"And silence, like a poultice, came
To heal the blows of sound."
An able fellow-student of mine, a Frenchman, once complained that he could not follow a train of reasoning given the morning's lecture. A feather-head standing near exclaimed, " Never mind, old man, we're all rowing in the same boat." "But, thank the Lord, not with the same sculls," was the prompt and witty reply. It is Mr Winwood Reade, I think, who somewhere says, " Life is bottled sunshine; and Death the silent-footed butler who draws the cork."
It must now be more definitely noted that these subtler scintillations of a brilliant intellect, though based on similarity, involve something more than simple resemblance of two focal ideas. There is no inherent similarity between silence and a poultice, or between a musical chord and a star. The similarity is not in the focal ideas, but in their relations. They may be expressed in the form of ratios. As a poultice is to the physical effects of a blow, so is silence to the effects of a street-band. As coloured rays are to starlight, so are separate notes to a musical chord. As withered leaves form a fertile soil for new plants, so will my dead thoughts form a fertile soil for new thoughts. And similarly in other cases. What we term the relation, is the transition from one focal state To another focal state. In view of these more complex cases of what I have termed association by perceived similarity of relationship, we may add to our former statement of the law the following: -- If the relation of two focal states a and I resembles the relation of two other focal states b and m, the recurrence of a : I mill suggest the recurrence of b : m. Or, more briefly, similar ratios or transitions suggest one another. We cannot follow this up further now. We shall hereafter see that this, which is the basis of poetical imagery, is also the basis of scientific insight and inference.
Concerning the principle of association 1), contrast, little need he said it is based upon the fact that strongly con-
(80) trasted ideas tend to suggest each other. A giant suggests a dwarf; beauty, ugliness; virtue, vice; and so forth. In such cases, however, there would seem to be always a bond either of contiguity (i.e. previous association in experience) or of similarity. We have perhaps seen or probably read of giants and dwarfs in connection with each other; and they are alike in being abnormal departures from the normal stature of man. That is to say, there is a similarity of relation. Good, bad; beautiful, ugly; virtuous, vicious; great, small; these are terms which, so to speak, go in couples, and thus come to be associated in the experiences derived from ordinary speech. Moreover, contrast is constantly used in early education. "Be good, and not naughty." "This is red and not blue." "What is the difference between solid and liquid?" Thus associations by contiguity are formed, and the perception of similar or dissimilar relations is fostered. Although, therefore, thereis no denying the fact that an idea may suggest its antithetical idea, there seems no reason forinvoking any principle of association other than those of contiguity or similarity.
Of these two, that of contiguity must undoubtedly be' regarded as the more primitive, and it is capable of the more definite and rigid enunciation. Both deal expressly with the focal elements of consciousness. But it must not be forgotten that in normal human experience the focal elements can never be regarded as isolated; and that in any normal sequence of focal elements m n o p q, the nature of any one of them is not determined only by the nature of its antecedent o, but also by the subconscious, and perhaps also the intra-conscious, accompaniments of o. This we have already illustrated in indicating the nature of divergent association, and in showing that the particular association in any special case is determined by the general drift of the mind at the. time being. I pass in my walk two men in
(81) conversation, and overhear the remark, " I don't care much for bowls." Owing to divergent associations with the word "howls," this does not convey much to me. But there was probably no doubt as to the meaning in the mind of the person to whom the remark was addressed. Perhaps they were discussing games, or had been talking of the news of the Spanish Armada reaching England; perhaps they were naturalists, and were comparing views as to the best shape for an aquarium tank; perhaps they were talking about Coleridge, and the influence of the sonnets of Mr W. L. Bowles on the poet's mind. I cannot say. It all depends upon the nature of the wave of consciousness into which howls was thus introduced. In autumn, and at evening, we look upon the world with different eyes from those which looked on the spring of the year in early morn. "There is," as Wordsworth says, "an imaginative influence in the voice of the cuckoo, when the voice has taken possession of a deep mountain valley, very different from anything which can be excited by the same sound in a flat country." "After all, it is upon the mind which a traveller brings along with him that his acquisitions, whether of pleasure or profit, must principally depend."
This leads us to notice in passing the influence of the mood one is in, and the temperament one is of, upon the dominant idea of the psychical wave. Mood and, temperament express respectively the transitory or relatively permanent condition of the body of the wave of which the dominant idea is the crest or summit. The sequence of ideas I as is different, according as one is sanguine or melancholic, choleric or phlegmatic The poetic temperament is in many respects different from the scientific, and both from the merely prosaic. In the prosaic person, association by contiguity reigns supreme; in the poet, association by similarity is rich and abundant. The man of science, if he have the gift of imagination, utilizes
(82) association by similarity but always seeks to make it subservient to, or at least to correlate it with, association by contiguity.
In conclusion, we may ask whether any given state of consciousness regarded as a whole is completely determined by the preceding state of consciousness. That is, using the letters m n o p q not merely to represent the focal elements, but states of consciousness in their entirety, is the state A completely determined by the state o? At a dinner-party the other night I had the misfortune on entering the room to say to my hostess one of those things which are better put differently if not left unsaid. This left a sore place in my mind, which continually smarted. I lapsed into unconsciousness of it from time to time when I became interested in the conversation of my charming companion. But in the pauses of the conversation, back it came into consciousness, and reminded me like conscience of my evil deed. Now here we must either say that during conversation my faux pas was present to consciousness, though I was not conscious of it, which sounds to say the least of it somewhat contradictory; or we must say that the state of consciousness p was not completely determined by the preceding state of consciousness o. The facts are best explained by saying that during conversation the faux pas remained in the extra-marginal infra-conscious region, overmastered by more powerful and insistent states of consciousness. If this be so, there are three ways in which a focal element in consciousness may be normally determined:
(1) In association with cerebral disturbances determined by an external stimulus in primary suggestion.
(2) In association with cerebral disturbances determined by preceding disturbances, dominant or sub-dominant, and therefore associated with consciousness or subconsciousness.
(3) In association with cerebral disturbances determined by preceding infra-dominant disturbances not associated
(83) with consciousness, or whose psychical concomitants are infra-conscious.
According to the doctrine of determinism, every normal state of consciousness is determined in one or more of these three ways:
"In all psychical development," says Dr Stout in his Manual of Psychology, ,some kind of association and reproduction is involved. So much may be conceded to associationism. Its defect lies in making the whole process merely reproductive, to the exclusion of other modes of psychical interaction, giving rise to new and not merely reproduced results." It may be said that the law of association by contiguity is an analytic statement of the conditions of reproduction which are necessary to the genesis of experience; but that it must be supplemented by the laws which condition the synthesis involved in psychological production. Hence .the importance of supplementing any statement of the law of association by the qualification " under similar marginal conditions." When Dr Stout asserts that "the fundamental principle of association is not contiguity in the strict sense of the word, but rather continuity of interest," he is emphasizing the importance of these marginal conditions, for interest is the feeling tone which accompanies the relation of the focus to the margin in consciousness. In the suggestion by similarity considered in the latter part of this chapter, the marginal conditions rise, to the position of dominance. Now these marginal conditions are the relevant portion of the net result of experience and knowledge; and the higher the stage of mental development, the more important is their influence in modifying the course of further development, and in masking the effects at direct association.