CHAPTER IX.

MEMORY. MENTAL ASSOCIATION.

Memory. -- The term Memory, in ordinary Ianguage, designates the faculty of retaining, reproducing, and recognizing representations of past experiences. These several features of memory vary in degree of perfection in the same, and in different individuals. Viewed as the capacity for preserving our mental acquisitions this power has been called the Conservative Faculty. It is an essential condition of all knowledge. The simplest act of judgment, as well as the longest chain of reasoning, necessarily implies retention. But acquisition plus conservation is not enough. During the whole of our life the greater portion of our mental possessions lie below the surface of consciousness, and exist only in a condition of potential resuscitation. It is the power of recalling and recognizing these dormant cognitions which completes and perfects this instrument of knowledge. The act of recognition is radically distinct from the mere re-apparition of an old mental state; but both have been sometimes comprehended under the Reproductive Faculty.

Aristotle distinguishes between memory (mnêmê), the passive faculty of retention, and reminiscence (anamnêsis), the power of active search or recall. The division is analogous to that of modern writers into spontaneous or automatic memory, and voluntary memory, or the power of recollection. The operation of reminiscence is compared by St. Thomas to that of syllogising, a progress from the known to the unknown, from the remembered to the forgotten. As it involves volitional and rational activity it is restricted to man, whilst memory is common to the brutes. Hamilton confines the name memory to the retentive or conservative capacity of the mind, whilst under the reproductive faculty he includes both reproduction and recognition. The imagination proper, he describes as the representative faculty.

Reproduction. -- A brief study of our minds reveals the fact that even spontaneous thoughts and recollections of past events do not occur completely at random. Our fancy can, it is true, move in a very rapid and seemingly arbitrary manner, whilst widely remote actions and episodes often reappear in imagination in an unexpected and disconnected way. Still, closer attention to the reproduced states will usually disclose faint and unobtrusive connexions binding together the links of what looked like a haphazard series of thoughts.

Process of Recollection. -- But it is in the act of reminiscence or recollection, in the sustained effort to recall some past experience, we perceive most clearly that the current of representations which pass before our consciousness do not proceed in an entirely casual and lawless manner. Starting from a vague notion of the event which we wish to remember, we try to go back to it by something connected with it in time, in place, or by any other kind of affinity. We first endeavour to place ourselves in the mental situation of the original incident. Then we notice that by fixing our attention on any particular occurrence we bring it into greater vividness, and numerous attendant circumstances are gradually recalled. Our ordinary procedure is accordingly to seize upon, and intensify by attention, the force of that one of the newly-awakened recollections which we judge most likely to lead to the desired end. When our gaze is focussed on this fresh centre a new system of objects related by similarity, contiguity, or contrast, begins to emerge from obscurity, and here we repeat our process of choice, picking out again the most promising train. By reiterated selections and rejections of this kind we approach gradually closer and closer to the object of pursuit, until it finally flashes upon us with a more or less lively feeling of satisfaction. Throughout our investigation we must have had some vague idea, some general outline of the experience of which we are in search, in order to direct us along the most likely paths. This is made evident in the final act of recognition, for in this stage we become conscious that the rediscovered fact fits precisely into the vague outline still retained. The accompanying pleasure is due to the perception of agreement between the new and the old, together with the feeling of relief occasioned by having the undefined want satisfied.

Laws of Association. -- The study of such an operation as that just described convinces us that our recollections succeed each other not arbitrarily, but according to certain laws. Careful observation of our mental processes have enabled psychologists to reduce such laws to a few very general principles. These principles which condition the reproduction of phenomena of the mind have been called the Laws of Mental Suggestion or the Laws of the Association of Ideas. The chief of these are:

(1) The law of similarity or affinity in character.

(2) The law of contrast or opposition in character.

(3) The law of contiguity, comprising association a) in space, and (b) in time.

Similarity. -- The Law of Similarity expresses the general condition that the mind in the presence of any mental state tends to reproduce the like of that state in past experience; or as it is sometimes enunciated, mental states suggest or recall their like in past experience. The previous form of expression, however, possesses the advantage of calling attention to a point frequently overlooked by English psychologists, namely, that it is in the mind, and not in the transient phenomena, the binding or associating force dwells. An impression or idea, viewed merely as an individual phenomenon, contains no reason in itself why another mental event like or unlike it should be its successor. It is only the permanence of the Subject which renders association of the states possible. The mind, retaining as habits or faint modifications former experiences, resuscitates on the occurrence of similar or contrasted events the latent state, and recognizes the likeness which subsists between the new and the old. The vicious reasoning of sensationalist writers who explain both the mind and the material world, including the human organism, as a product of the association of ideas is thus obvious.

Examples of association by similarity are innumerable. A photograph recalls the original, a face that we see, a story that we read, a piece of music or a song that we hear, all remind us of similar experiences in the past. Even the less refined sensations of touch, taste, and smell, cause us to recollect like impressions in our previous life. Painting, sculpture, the drama, and the rest of the fine arts, seek to please by their success in imitation. The pleasures of wit and humour, the charm of happy figurative language in poetry or prose, and the admiration won by great strokes of scientific genius, are in the same way largely based on the satisfaction of the tendency by which the mind is impelled to pass from a thought to its like.

Contrast. -- The Law of Contrast enunciates the general fact that the mind in the presence of any mental state tends to reproduce contrasted states previously experienced. Or it may be formulated in the proposition that mental states suggest contrasted states of past experience. The idea of prodigal wealth recalls that of needy poverty, cold suggests heat, black white, virtue vice, and so on. From the beginning, however, this law has been felt to be reducible to more ultimate principles. In fact, to declare broadly that mental states are inclined to revive former perceptions both like and unlike them would approach paradox, if not actual contradiction. The truth is, this law in so far as it is mental and not an effect of organic reaction is a result of the combined forces, similarity and contiguity. This will be made evident presently.

Contiguity. -- The Law of Contiguity formulates the truth that the mind in the presence of an object or event, whether actual or ideal, tends to recall other objects and events, formerly closely connected in space or time with that now present. It is often impossible to draw a rigid line between associations due to close connexion in time and those founded on contiguity in space. When looked at from the mental side, we say the subjective impressions occurred simultaneously, or in close succession; viewed from the opposite standpoint, we say the perceived objects were locally contiguous. Suggestion by contiguity whether in space or time is the most important and far reaching form of association. It is not confined to cognitive acts, but includes emotions, volitions, and external movements as well. It is the principle upon which every system of education both mental and physical is based; and by the sensationalist school in this country it has been erected into an omnipotent agency through which all knowledge and belief regarding space and time, mind and matter, have been created. We have pointed out in treating of sense-perception how the taste, smell, touch, and sight of objects mutually suggest one another. Contiguous association is also a leading source of our pleasures and pains. The process of learning to walk, to speak, and to write, and the acquisition of the various manual arts, rest upon the tendency of acts which are repeated in succession to become so united that each impels to the reproduction of the next. Language is possible because auditory sounds grow to he associated on the one side with the visual image of the object, and on the other with the complex cluster of motor or muscular impulses involved in the utterance of the name; and literature is intelligible only through the marvellous command which repeated associations have given us over the innumerable combinations of individual letters which cover the page of a book.

Time order. -- Although, as we have said, associations in space are often intimately related to connexions in time, there is one important feature in which these latter differ from the former. Owing to the permanent coexistence of the separate parts of an extended object, and to our visual power of simultaneously apprehending these parts, no particular point becomes endowed with any special priority; consequently we can in imagination, as in the previous reality, pass in any order from each point to every other. But in serial states, where each separate impression has dropped out of consciousness before the appearance of the next, the whole force of the association is to reproduce the mental states in their original order of occurrence.

Reduction of these laws. -- Contiguous suggestion is an agency of such extensive range in mental phenomena that some psychologists hold similarity, contrast, and all other forms of association, to be merely special applications of this ultimate principle. Others, on the contrary, consider contiguity to be a particular case of similarity -- likeness in space or time.

Contrast analyzed. -- That the law of contrast is resolvable we have before stated. Contraria sunt ejusdem generis. Contrast presupposes similarity in genus. There is no disposition in the mind to pass from the idea of civilization to that of liquid or of black, because there is no relation of similarity between them. But there is an easy transition in thought from civilization to barbarism, from solid to liquid, and from black to white, because each pair of terms refer to a common class. Still this does not quite complete the explanation, as there may be many species in the class, and there is no special inclination felt to pass to intermediate objects, such as from white to green or red. It is here the principle of contiguous suggestion supplements that of similarity. We are accustomed to meet in literature, in language, and in daily experience, contrasted terms and objects bound together in pairs; and in fact the entire judicial function of the intellect consists in the discrimination of unlike things, and assimilation of those which are like, so that we naturally acquire a facility for passing from a notion to its opposite.

Attempted analysis of similarity. -- The effort to reduce similarity and contiguity to a single principle is not quite so successful, though they are evidently connected. Psychologists who maintain that contiguity is the most general principle, explain suggestion by apparent resemblance as really due to the fact that those features in the present object which also existed in the former object arouse by contiguity the parts which were adjacent to them on that occasion. Thus, when the face of a stranger reminds me by similarity of an old friend, it is held that the process consists of a deeper impression of the common features, which results from the fact of these features having been previously perceived, and then a consequent reinstatement of the lineaments, formerly contiguous, whilst our interest and attention is withdrawn from those adjacent in the present experience.

The following analysis of Similarity is given by the German psychologists Maas and Biunde: Let the face now seen for the first time be called B. Let the former face recalled through the resemblance of B be styled A. Let the points common to both be called m. Let the unlike features peculiar to B be named b, and let those peculiar to A be named a. Now, when B is observed, the familiar but unexpected feature m attracts notice, while the less interesting b is ignored. But m has been formerly frequently joined with a constituting the total representation A, and accordingly bringing back its old associate it reinstates A. "When, for example, I look at the portrait of Sir Philip Sydney, I am reminded of its likeness to the portrait of Queen Elizabeth, because of the ruff which is about the neck of each, which in this case is the only common feature, and attracts at once the attention. The ruff brings back everything besides in Her Majesty's portrait -- the head-dress, the features, the sceptre the robes, &c., till the whole is restored."^{1} Mr. J. Ward on similar lines contends that it is in previous contiguity alone the associative or suggestive force lies, and that simiIarity, is only an incidental relation recognized after the reproduction is accomplished.^{2}

Attempted analysis of contiguity. -- Writers who look upon similarity as the ultimate law, describe contiguity as merely a particular case of resemblance. No part of the present representation, it is urged, can be" common" to the previous mental state in the strict sense of being numerically one and identical on the two occasions. Even the mental states aroused by the contemplation of the same object now and five seconds ago are two really different conscious acts. But it cannot be denied that an experience -- a sensation, an intellectual cognition, or an emotion -- often recalls a similar state that occurred amid completely different surroundings at a very distant period. There is, for instance, no connexion of contiguity between the present perception of a photograph seen for the first time and a friend's face whom I have not met for twenty years. We must therefore, it is argued, admit as an ultimate fact this tendency of the mind to reproduce past experiences connected with the present by likeness alone. Moreover, cases described as contiguous associations are merely particular forms of similarity -- likeness in space or time. When, for example, a bridge recalls the image of a house that used to stand hard by, the association is said to be one of a partial resemblance between the present and past mental states. The mind is at present in a state like that in which it was before.

Herbert Spencer makes similarity the sole ultimate principle: "The fundamental law of association is that each (mental state), at the moment of presentation, aggregates with its like in past experience. . . Besides this there is no other; but all further phenomena of association are incidental." Similarly Höffding: "Every association by contiguity presupposes an association by similarity, or at least an immediate recognition. When the apple before me carries my thoughts to Adam and Eve, this is because first -- perhaps so quickly that I am hardly conscious of it -- I have thought of the apple on the tree of knowledge. The association by similarity at the root of association by contiguity may easily escape uur attention. But it is a link which cannot be dispensed with." (Op. cit. p. 158.)

Hamilton originally accepted the analysis of Maas, and enounced as the one comprehensive principle of Association the Law of Redintegration or Totality: Thoughts suggest each other which have previously constituted parts of the same entire or total act of cognition.^{3} Moreover he traced the recognition of this principle back to St. Augustine,^{4} and even to Aristotle. Subsequenty, however, in his work On Reid, Note D,*** Hamilton abandoned this view, and acknowledged both Similarity and Contiguity as irreducible. He thus formulates the two principles: (1) The LAW of REPETITION, or of DIRECT REMEMBRANCE: -- Thoughts co-identical in modification (i.e. similar as acts of the mind) but differing in time, tend to suggest each other. (2) The LAW of REDINTEGRATION, of INDIRECT REMEMBRANCE, or of REMINISCENCE: -- Thoughts once co-identical in time, are however different as mental modes, again suggestive of each other, and that in the mutual order which they originally held. The terms Direct and Indirect mark the fact that a mental state immediately or directly recalls its like in the past, and mediately the unlike states formerly contiguous to this restored element. This latest position of Hamilton is akin to that of St. Thomas, as will be seen later.

Criticism. -- It seems to us that similarity and contiguity, though they are usually allied in their operation, contain each a separate element of its own. On the one hand, it is a fundamental irreducible law that present mental states tend to awaken representations of their like in past life. On the other, these reproduced representations usually call up unlike adjacent elements, which formerly co-existed along with them. The second fact cannot be really resolved into the first, nor the first into the second. We may of course manage to include both forms of suggestion in one verbal statement, but their radical difference will still remain. Though the adjectives "similar" or "same" maybe used to mark agreement of date as well as likeness of quality, we must not forget that coincidence in time is something essentially different from affinity in nature.

Physiological hypothesis. -- It is suggested that the physiological counterpart of the law of suggestion by contiguity lies in the tendency of groups of cerebral nerve elements which have acted together in the original experience to do so again whenever any portion of the group is stimulated. The hypothesis seems plausible though, of course, there is no direct evidence on the point.

The physical correlate of the law of similarity is supposed the same way to consist of a certain "sympathetic" power of a present neural excitation to re-awaken to activity nervous elements formerly excited in a similar way. The neural tremor accompanying the original cognition left it is assumed in the cerebral substance, an abiding disposition to repeat itself; and the present similar excitation -- presumably in different cellular matter -- it is supposed, may by a sort of sympathetic influence evoke a rehearsal of the old movement. This we confess seems to us much less satisfactory. In what sense is the cerebral neural tremor corresponding to the retinal image of a six-inch photograph peculiarly like that excited by the original -- a six-foot man -- seen three months ago? How is this "sympathetic affinity" to be conceived? It seems to us that suggestion by similarity -- where this cannot be reduced to contiguity -- involves the higher supra-sensuous activity of the mind, to which the appropriate cerebral action is unimaginable. Hence the difficulty.

Co-operative Associations. -- The terms compound, or complex associations, are used to designate those forms of suggestion where two or more distinct lines of connexion co-operate in the reproduction of a mental state, or series of mental states. The word co-operative appears to us to describe more accurately the nature of this process in which several separate strands join together to intensify the force of association. The phrase, conflicting associations, will then designate with precision those contrasted phenomena in which the lines of suggestive force are divergent. Instances of co-operative association are abundant; in fact, we rarely find suggestion acting along a solitary isolated path. The recollection of a poem may be effected partly by auditory associations of rhyme and metre, partly by the succession of connected thoughts, and partly by the visual picture of the page on which the verses were printed. Most familiar acquisitions such as walking, speaking, writing, brushing our hair, playing the piano, are the result of the co-operation of parallel series of tactual, motor, and visual or auditory series of associated sensations; and the great assistance which local associations afford in resuscitating forgotten events where the other links have become attenuated is well known.

Conflicting Associations. -- Conflicting or obstructive associations illustrate the incidental disadvantages which we so frequently find attached to the working of a generally useful law. Just as a desired recollection may be facilitated by several convergent associations of similarity or contiguity, so may it be impeded by their divergence. A verse, or a word, which is connected in a poem or speech with more than one context, frequently tends to shunt us off the right track. The aim of the riddle or conundrum is this very result. The recollection of a name of which we possess the first letter may be similarly obstructed; and the accidental presence of any strong counter-association connected with a present idea, may temporarily interfere with our power of reminiscence. The best method of procedure in such cases, experience teaches us, is to secure a new unprejudiced start by turning away from the subject altogether for awhile, until the vivacity of the connexion between the obstructive word or idea and the divergent series has diminished, or until we can hit upon some independent line of suggestion when the pursuit may be resumed with better prospects of success. The sudden revivals of lost ideas, whilst we are immersed in a new occupation, after a vainly protracted search, are in this way explained. Psychologically misleading associations were in the ascendant during our futile struggles, and physiologically the perturbed state of the brain rendered the reproduction of the neural correlate of the desiderated representation impossible. But the subsequent readjustment gave rise to the particular set of conditions psychical and physical which made resuscitation feasible, and which, either automatically or influenced by a lingering semi-conscious volition, disinterred the lost thought.

Secondary Laws. -- In addition to these Primary laws of association or suggestion, there are certain other general conditions determining the efficiency of memory and recollection. Some, or all of these, have been variously expressed under such titles as, the law of preference, the secondary laws of suggestion and general conditions of acquisition and reproduction. However they be described, they serve to explain the varying force of associations not accounted for by the other group. The leading principles in this secondary class are: (1) Vividness of impression; (2) Frequency of repetition; and (3) Recentness.

Vividness. -- Assuming the action of the other laws to remain constant, the deeper, the more intense, or the more vigorous the original impression, the more permanent is its retention, and the easier its reproduction. The vividness of an impression is itself dependent objectively on the inherent attractiveness or force of the stimuli, and subjectively upon the energy of our voluntary attention. The novelty, beauty, or overwhelming power of a single experience may give it life-long permanence; and deep interest or intense application of attention may largely compensate for the absence of the other conditions of reproduction. To awaken and sustain interest must therefore be always a chief aim of the teacher, as whatever is learned by this motive is both acquired with greater facility and retained with greater tenacity.

Frequency. -- The influence of repetition need not be dwelt on. By reiteration, especially at short intervals, the feeble association created by the first contiguous occurrence of two events becomes gradually converted into an almost irresistible suggestive force, and a frail link of similarity is changed into an iron bond. It is by repetition that in the last resort all other imperfections of memory must be made good.

Recentness. -- The third law is also familiar. The shorter the time that has elapsed and the fewer the intervening impressions, the more easily a past thought or series of thoughts is recollected. Consequently it is important that the first lessons in a new subject be repeated at brief intervals, otherwise the effect of each impression will have completely faded away before the next effort. The co-operation of one or more of these laws with one or more of the others will account for variations in the suggestiveness or suggestibility of particular mental states.

Order of reproduction. -- Of two associated terms, such as a name and its object, a sign and the thing signified, a means and its end, one may have far more power of recalling the other than vice versa. This may be due either to the customary movement of our attention in a regular order, as in the case of repeating the alphabet, or to the direction whither our interest naturally tends, as where symbols or means point to the ultimate object. It may also be due to the circumstance that one of the terms has been met with more frequently, or more recently than the other, or to the fact that it is connected with a larger number of co-operative threads of association now present.

Retention. -- The problem of the conservation of experienences has been as keenly discussed as that of reproduction. That cognitions do de facto persist in some form, whilst not realized in consciousness, is indeed only a hypothesis, but yet one which is irresistibly forced upon us. We have continuous evidence that we can recall familiar past events, and we are consequently convinced that they have dwelt within us during the interval. The theory offered by Aristotle and the schoolmen on this subject was summed up in the phrase which describes the memory as thesaurus specierum. By species, as we have already stated, the scholastic philosophers understood modifications which reflect in a psychical manner external objects, and which have been excited in the soul by the action of these objects. These species or cognitional acts were classed as sensuous or intellectual according as they pertained to intellect or sense, and the mediaeval psychologists taught that when experiences have disappeared from consciousness the soul is endowed with the capacity of retaining these modifications as faint dispositions or habits. But the retention is not solely mental; the organism co-operates. The soul is not a detached spirit, but an informing principle dependent on the body which it animates. Consequently the latter co-operates in conservation and reproduction, just as in the original perception. The physical impression, like the mental act, must persist in a habitual manner ready to be recalled into activity on an appropriate occasion.^{5}

Ultra-Spiritualist theory. -- Modern writers who have departed from this view have commonly erred by accounting for memory as a property of the soul alone or of the body alone. Sir William Hamilton looks on all physiological hypotheses on the subject as unphilosophical, and as affording no insight into the nature of memory, and he asserts that "all of them are too contemptible even for serious criticism."^{6} This remark is perfectly just if the physical theory by itself be advanced as an adequate explanation of memory, that is, apart from any retention by the permanent mind; but otherwise it is untenable.

Physiological basis proved. -- That there is a subsidiary concomitant process of organic conservation, on which the mind is at least partially dependent, is rendered probable by a multitude of facts. (1) In youth, while the organism is most plastic, we are capable of acquiring easily the most enduring habits and recollections. (2) The faculty becomes impaired in later life as the organism grows less pliable. (3) Injuries of the brain, fevers, and cerebral diseases, frequentlv act in a striking manner on memory whilst the other cognitional faculties remain unaffected. Determinate periods of life, special kinds of experience, classes of words, particular languages, certain parts of speech, and even individual letters, have been suddenly erased by physical derangements of the cerebrum. (4) Moreover, these losses have often been suddenly restored on the recurrence ol abnormal cerebral conditions. (5) Finally, in ordinary experience health, vigour, and freshness of the brain are found to be most important conditions of the acquisition of knowledge.

Hamilton's own theory is that of Herbart and many German spiritualist philosophers. He explains memory, in accordance with the doctrine of latent or unconconscious mental modifications, as a result of the self-energy of the mind. Presentations or cognitions are not passive impressions, but spontaneous activities of the soul, exerted on the occasion of external stimuli. As modes of a subject one and indivisible they cannot be destroyed -- a part of the ego must be detached or annihilated if a cognition once existent be again extinguished. The real problem with Hamilton, then, is not that of remembrance, but of obliviscence; and this he explains as due to the gradual enfeeblement and obscuration of former states owing to the rise at successive activities into the limited sphere of consciousness. This delitescence or subsidence of the old energies is continuous, but they are never completely obliterated.

Regarding this doctrine we have room here only to point out the erroneous idea involved in conceiving a past act of perception as persisting in a merely lowered degree of activity. In such a view consciousness would be but an accident of cognition. This error is traceable to the literal interpretation of metaphorical language regarding the surface of consciousness. A cognition cannot whilst retaining its reality as a cognition, sink into unconsciousness, just as a balloon or a diving-bell descends into denser or more profound strata. The true conception of retention is the old one, per modum habitus. An act of knowledge when it has passed out of thought is no longer an activity or energy; as an act it has perished, but during its existence it wrought an effect on the soul in the shape of a habit or disposition, which on the recurrence of suitable conditions is capable of giving rise to a representation of the former state.

Purely Physical theory. -- Far more seriously erroneous, however, is the theory which, exaggerating the capacity of the organic factor, would explain memory in purely materialistic fashion. Dr. Bain, Mr. Spencer, Dr. Maudsley, and M. Ribot, are well-known representatives of this view. Memory is in this hypothesis, "per se a biological fact -- by accident a psychological fact."^{7} To each cognitive act, sensuous or intellectual, there corresponds a definite disturbance of some group of nerve-fibres and nerve-cells in the brain. Such a cluster of neural elements vibrating or acting together in any way retain a tendency to act in a similar way again. Lines of least resistance are formed, and every repetition of a conscious act with its regrouping of the appropriate collection of cells gives greater stability to the cerebral registration. These organic modifications are, however, according to the more recent exponents, to be viewed, not so much in the light of mechanical impressions stamped upon the substance of the brain, as "dynamical affinities" or alliances, created between separate centres of activity by means of which simultaneous re-excitations of the original groupings may be secured. The revival of the old neural tremor affords then, it is supposed, an abundantly sufficient explanation of the phenomenon of recollection. " Memory is, in fact, the conscious phase of this physiological disposition, when it becomes active or discharges its functions on the recurrence of the particular mental experience."^{8}

Recognition. -- The weak point of this theory when put forward as a complete explanation of memory is that it simply ignores the essence of the problem -- the act of recognition. Apart from the insuperable difficulty due to the physiological law of metabolism -- the fact of perpetual change going on in the material substance of the body -- this hypothesis fails to distinguish between the reproduction of states like former ones and the identification of this similarity. The problem to be solved is how some striking experience, such as the sight of Cologne Cathedral, the death of my father, a friend's house on fire, the first pony I rode, can be so retained during a period of fifty years that, when an old man, I feel absolute certainty of the perfect agreement in many details between the representation of the event now in my mind and the original perception. The circumstance that the passage of a neural tremor through a system of nerve-fibres may leave there an increased facility for a similar perturbation in the future, in no way indicates how this second excitation or its accompanying mental state is to recognize itself as a representation of the first. To account for the facts there is required a permanent principle distinct from the changing organism, capable of retaining the old states in some form or other, and also in virtue of its own abiding identity, capable of recognizing the resuscitated image as a representation of the former cognition. Given such a principle, the persistence of physiological "traces" or "vestiges" may facilitate its powers of reproduction, and may serve to account for differences in individual endowments; but without such an abiding mind the plastic properties of the nerve are useless to explain the phenomenon.

The fact of recognition is invariably overlooked in this point of the controversy by the adversaries of mental retention. Thus Mr. Mark Baldwin asserts that a cognition is "a mental product dependent upon a (cerebral) process, and in the absence of this process it simply ceases to exist. The true answer to the question, as to where the presentation is in the time between perception and memory (reproduction) is no where." (Op. cit. p. 156.)

To this it may be objected that it is by no means easy to define precisely where the cognition is even when revived. There is probably a commotion in some part of the cerebrum, but obviously that is not the "mental product." Secondly, Mr. Baldwin is quite right in urging that the presentation no longer exists in an actual condition. Certainly not, after the Herbartian view, "sunk in sub-consciousness like a stone in a lake." Still, the fact of recognition implies more than an abiding modification of brain substance to connect the two mental events. The act of recollection is not simply the production of a mental state like the former due to the repetition of a similar cerebral process. It is not merely "a really new presentation" resembling the old image. It involves a recognition of agreement between the present state and the previous experience possible only if that experience has been retained in some form or other by the agent who identifies them; and this agent is not merely an aggregate of cellular matter. Whether we choose to speak of the retention as accomplished through species, or "modifications," or "dispositions" wrought in the mind, the persistence of the effect of the former mental act in the mind, and not merely in tbe brain, is the only means by which we can rationally account for the subsequent identification of the present with the past experience.

Reminiscence. -- Besides recognition, however, the special form of active or voluntary memory termed recollection, or reminiscence, refutes the materialistic hypothesis. In this operation the mind controls and directs the course of its ideas. The process involves reflexion, comparison, and active intellectual cognizance of relations, whilst the free acceptance or rejection of selected lines of thought constitutes its most essential feature. Now, at the very most, the purely physical theory might account for the awakening of representations of former experiences by the accidental action of some external stimulus which sets the group of nerves engaged vibrating in the old way. But if there be no such external stimulus how is the recollection to be explained? Undoubtedly, faint sense impressions coming from without sometimes resuscitate involuntary memories, but our every-day life assures us that long past occurrences are also deliberately recalled by the mind itself. It tells us that we can employ the laws of association to reproduce at choice special series of events, and that according as they arise we can again select particular individuals from these series to form new starting-points. But clearly the mere persistence of modifications in the cellular substance of the brain could not account for this operation.

It has been well said "The sensory cell is not self-acting; it does not of itself originate sensation. And if it be not, we need, in default of impulse from without, impulse from an inner sphere of experience, where intellectual activity proceeds under laws quite different from those which apply in connection with purely sensory action."^{9}

Intellectual and sensuous memory. -- This third element of memory involved in the act of recognition introduces us to the question: Is memory a sensuous or an intellectual faculty? Although recollection in man commonly involves intellectual activity, we have discussed memory here along with the sensuous powers of the mind because a large portion of the phenomena of this faculty do not transcend the order of sensuous life; and it is of the utmost importance that mere increase in refinement or complexity should not cause sense to be confounded with intellect, a mistake which is so often made in English philosophical literature.

Dr. Bain, for instance, of his large volume on The Senses and the Intellect, devotes the half entitled Intellect to expounding the association of mental states. Now, in our view, this is in the main what intellect is not. The laws of suggestion or association are best exhibited in the purely automatic working of reproduction, and they account for the various operations of animal consciousness; but they are in no way characteristic manifestations of the superior rational activity which constitutes intellect, though of course cognitions of an intellectual order may suggest each other.

Neither the acquisition, nor the retention of sensuous impressions, nor even their automatic reproduction under the laws of suggestion, exceeds the range of sense. Nay, there is nothing incompatible with the nature of an exclusively sentient mind in the presence of a feeling that a revived image is familiar or has been presented to us before. A man whose intellectual activity is completely absorbed in some abstract train of thought may make a complicated journey through a city, or perform any other familiar mechanical operation, guided by sensuous memory and the hardly noticed impressions of various well-known objects. But besides such processes as these, man can acquire, retain, and reprodoce rational cognitions; he can recall past acts, sensuous or rational; he can formally or explicitly compare the present representation with the past experience, and recognize identity or difference between them; he can form the notion of time; and he can by a reflective process of reminiscence localize an occurrence at a determined date in the past. In all these operations intellect is essentially implied, and consequently we must admit a rational as well as a sensuous memory.

Scholastic controversy. -- There has been much subtle discussion among the schoolmen as to the forms and modes of memory which are to be deemed sensuous or intellectual. St. Thomas, in a well-known passage^{10} says: "Cognoscere praeteritum ut praeteritum est sensus," but the "ut praeteritum" may have more than one signification. Suarez maintains that "intellectus rem cognoscit cum affectionibus seu conditionibus singularibus perfectius multo quam sensus;" also that "Sensus novit praeteritum tantum materialiter, intellectus vero formaliter." Amongst recent text-books of note, Lahousse asserts, "Absurdum est (dicere) memoriae sensitivae proprium esse apprehendere praeteritum determinatum, uti est praeteritum," and he urges, "Ens praesens non apprehenditur a sensu tanquam praesens; apprehendi enim deberet ratio praesentiae ut sic, quae ratio abstracta non attingitur a senso." Sanseverino defends a somewhat different view. St. Thomas appears at times to say that past events are cognized as past per se by sense, and only per accidens by intellect; elsewhere, however, he explicitly distinguishes between the remembrance of a past object and of the percipient act by which it was apprehended. The memory of the former he considers as per se sensuous, though per accidens it may belong to intellect. The proper object per se of intellect is the essence or nature of things without reference to present, past, or future. Time is a particular determination merely incidental to an object, and is apprehended by the universal faculty only indirectly through reflexion. As regards a previous percipient act, however, it can be known as last by the intellect not merely thus per accidens, but per se. Still even here the definite chronological situation, like every other individual determination, only indirectly apprehended by intellect through reflexion, and is accordingly merely per accidens the object of that faculty. St. Thomas thus seems to teach that the occurrence of a sensuous impression of an object may carry with it the feeling that this object has been apprehended before, and this feeling may even refer the occurrence to a definite point of the previous time series, just as an external sense may localize a body in space. The formal recognition, however, of agreement between a present representation and a past object or state must, on St. Thomas' principles, be deemed an act of intellect. This is the feature of memory most in Suarez' mind, and Dr. Gutberlet would apparently account for some of the differences of opinion on the subject by the term "memory" being used by other writers mainly to signify reproduction apart from recognition. The reader wishing to study the question at length may consult St.Thomas, Sum. i. q. 79. a. 6, Qu. Disp. de Verit, q. x. a. 3, c, and De Mem. et Rem. l. 2; Suarez, De Anima, IV. c. x.; Lahousse, Psych. III. c. x. a. 5; Sanseverino, Dynam. c. vi. a. 2; Liberatore, Psych. c. i. a. 7; and Gutberlet, op. cit. p. 108.

Qualities of good memory. -- The estimation of time, the localization of events in the past, expectation and some other operations connected with memory, will be more conveniently treated in a future chapter. But we may add a word here on the qualities of a good memory and the aim of the teacher with respect to this facuIty. Excellence of memory is measured by facility of acquisition, tenacity, and readiness of reproduction. These properties frequently exist in the same person in inverse degrees of excellence. The lawyer and the actor attain great perfection in the rapidity with which they can commit to memory the facts of a new case or a part in a new play, but in a short time the whole subject is again erased from the mind. The capacity of memory varies much in different individuals, and history affords us many examples of powers that seem to the ordinary mind marvellous.

Thus Ben Jonson, it is alleged, could repeat all that he had ever written, and most of what he had said. Scaliger learned by heart the Iliad and Odyssey in three weeks, and the whole of the Greek poets in three months. Pascal, it is said, could remember anything he had ever thought. Lord Macaulay could after a single attentive perusal reproduce several pages of a book, and discovered by accident that he could repeat the whole of Paradise Lost. Cardinal Mezzoffanti knew forty-eight different languages and many dialects.^{11}

Training of the memory forms an important part of the first stages of all systems of education. The teacher must here carefully distinguish between instruction or the storing the mind with useful information and education proper or the development of mental faculty. Accordingly, although many of the earlier educational exercises aim primarily at the acquisition of certain necessary items of knowledge such as the alphabet, parts of speech, meanings of words, tables and the like, which must be learned by sheer force of repetition, nevertheless the teacher's chief aim must be to cultivate in the pupil a habit of judicious, not of mere mechanical memory. That is, he must accustom the child to exercise remembrance by means of the internal or rational connexion of ideas rather than by mere contiguous association. He must see that the subject-matter is understood and not merely reproduced by rote. Further, he should profit by the teaching of physiology and psychology: (1) to avoid over-estimating the feeble powers of the very young; (2) to allot the period when the brain is physically in the best condition for the work of learning by heart; (3) to exercise the mind in frequent repetition at short intervals in order to deepen the first impression before it has faded away.^{12}

Historical Sketch. -- The phrase, Association of Ideas, has played such an important part in the history of English Philosophy that it appears to us advisable to make a few additional remarks on the subject. The reality of association as a principle governing the faculty of recollection is undeniable, and has been recognized by philosophers from the time of Aristotle. In the light, however, of a hypothesis put forward to account for certain peculiar intellectual states, it seems to have been first advocated in this country by Hobbes, and later on with far greater ingenuity by Hume. It is in this second sense that Associationism has become the central tenet of the English school of thinkers which has thence received its title.^{13}

Mental Association, as the universal condition of memory, was distinctly expounded and reduced to the three general laws of similarity, contrast, and propinquity in time, space, or some extrinsic relation, by Aristotle. In a very erudite article,^{14} Hamilton vindicates for the Greek philosopher the honour of having first discovered and formulated these laws. We can only afford to cite a few sentences freely translated by Hamilton, but the whole chapter of the De Memoria et Reminiscentia dealing with the subject is well worthy of study. "Reminiscence," says Aristotle, "takes place in virtue of that constitution of our mind, whereby each mental movement (modification) is determined to arise as the sequel of a certain other. . . . When, therefore, we accomplish an act of reminiscence, we pass through a certain series of precursive movements, until we arrive at a movement on which the one we are in quest of is habitually consequent. Hence, too, it is that we hunt through the mental train excogitating what we seek from (its concomitant in) the present or some other (time), and from its similar or contrary or coadjacent. Through this process reminiscence is effected, for the movements (i.e., mental modifications) are in these cases sometimes the same, sometimes at the same time, sometimes parts of the same whole, so that (starting thus) the subsequent movement is already more than half accomplished."^{15}

St. Thomas, in his Commentaries, developes the doctrine of Aristotle in a manner which exhibits close study of the nature of mental association. The ultimate cause of remembrance, he repeats, lies in the native tendency of the mind to reproduce representations in the order of the original impressions.^{16} He then passes on to amplify Aristotle's treatment of the mode of reminiscence, and to expound more fully the general laws governing reproduction. The process of recollection may advance, he observes, along a time series of events, from the recent to the most distant, and vice versa; or starting from a known object it may be guided by any of the three indicated relations. At times remembrance is awakened by force of similarity, as when thinking of Socrates we are reminded of Plato, who resembled him in wisdom. At other times the bond of connexion is contrariety, as when the thought of Hector recalls that of his opponent Achilles. Finally, the third principle of suggestion is vicinity in space, or time, or some other form of propinquity. After illustrating by examples these three general laws, he goes on to indicate in a much clearer manner than Aristotle their further analysis and reduction: In all three forms of suggestion the ultimate ground of reminiscence lies in the connexion of the previous "movements" of the soul. Association by similarity is due to identity in mental modification subsisting between the similar experiences. Contrast is based upon the simultaneity of the two terms in apprehension. Local propinquity and other modes of contiguity are merely cases of partial similarity; impressions produced by adjacent objects overlap, and the common part in the revived state reproduces its ancient collateral features.^{17} We have thus co-identity in nature and in time, or what Hamilton calls the laws of direct and of indirect remembrance, laid down by St. Thomas as the two general principles of association. Accordingly, notwithstanding the contempt which writers of the Associationist school have invariably exhibited towards the schoolmen, we find in these terse remarks of St. Thomas, now over six hundred years old, a statement and analysis of the Laws of Association virtually as complete and exhaustive as that given by any psychologist from Hobbes to Mr. Herbert Spencer.

Of the later scholastics, Vives goes most fully into the treatment of this subject, and it is scarcely too much to say that there is no form of association viewed as a condition of memory which he has not expounded and illustrated.^{18}

The chief interest, however, in the history of the doctrine of mental association centres in modern psychology; and it is there that we find association advocated not only as a general condition of reproductive memory, but also as a philosophic principle adequate to explain the constitution of numerous important mental states. Locke, in the Essay, in 1685, contributed the phrase Association of Ideas, as the title of a chapter dealing with peculiarities of character, but did little more on the subject. Hobbes had previously made occasional observations on the power of association, but it is clear from the terms and phrases which he employs, that, in spite of his vigorously expressed contempt for the schoolmen, he silently borrowed from them on this topic.

In this country, nevertheless, it was not till Berkeley's writings appeared (1709-13), and still more decidedly in Hume's Essay on Human Nature (1728), that mental association was insisted on as a virtually omnipotent principle in the genesis of knowledge. But on the Continent, already in the middle of the seventeenth century, Pascal, and after him Malebranche, had indicated the extensive influence of mental association; and even Condillac was as early as Hartley, who is the recognized founder of the Associationalist school in this country. In his Observations on Man (1748), in connexion with a theory of neural vibrations, Hartley expounded a system nf mechanical association, in which imagination, memory judgment, reasoning, emotions, and passions, are all reduced to associations of sensations. Later on in the century, Associationism was advocated by Tucker in the science of Ethics, and by Alison in the sphere of AEsthetics. Approval and remorse, good and evil, beauty and ugliness, were all analyzed into pleasant and painful sensations associated in experience with certain actions and objects.

At the beginning of the present century James Mill, in his Analysis of the Phenomena of the Human Mind (1829), reexpounded the doctrines of Hartley and Hume, and may be styled the second founder of the school. Sensations, and ideas, which are merely faint reverberations of defunct sensations, worked up in various ways by force of association, and especially by that form of suggestion included under the law of indissoluble association, account for the sum-total of our mental possessions. Sensations or ideas, repeatedly recurring together or in close succession, and never apart, tend to combine in such an indissoluble or inseparable manner that one necessarily or irresistibly suggests the other.^{19} By a species of "mental chemistry" the contiguous states fuse or combine, so as to generate products utterly unlike the constituent elements. The visual appearances of objects come thus to suggest irresistibly their distance, and we imagine we see an object to be hard, soft, hot, cold, rough, or smooth. By this means are created such universal illusions, as the necessity of mathematical judgments, the unity of the mind, and the externality and permanence of a material world.

John Stuart Mill and Dr. Bain develope the same principles, and enrich their treatment with numerous ingenious illustrations. The effect of hostile criticism from various standpoints has been to modify very considerably the treatment of Psychology by the more recent representatives of associationism. Dr. Bain's chief contribution to the resources of the school was the allotment to the mind of a reservoir of spontaneous activity continually fed by the accumulation of superfluous muscular energy. By judicious management of this new fund, many deficits in the sensist theory of both the cognitive and volitional departments of mental life could, it was believed, be made good.

In still greater contrast to the views of James Mill and the earlier writers of the school, is the exposition of the Associationist system offered by Mr. Sully in his Outlines of Psychology. (Cf. cc. ix. x.) The old doctrine of a purely passive mind, wherein sensations through a process of agglutination coalesce into all kinds of intellectual products, is virtually abandoned, and intead we have ascribed to the mind active powers of attention, comparison, and judgment. This last act, too, is not, as with Mr. Bain, the "fact of similarity or dissimilarity" -- the capability of experiencing like or unlike feelings -- but the intellectual faculty of cognizing this relation of likeness or unlikeness. These considerable improvements, which bring the sensist theory of mental life more into harmony with the results of actual observation, and help to obviate some of the most telling objections urged against the unreformed doctrine, are, on the other hand, very dearly purchased from a logical point of view. It is difficult to see how the fundamental article of the Sensist school -- the tenet that the mind is nothing more than a cluster or series of feelings -- can be harmonized with the imported doctrine, which attributes to this "mind" the active power of discriminating, combining, and organizing these states. The truth is, the best part of Mr. Sully's description of mental operations belongs to an alien conception of the mind, and is not easy to reconcile with his general position as a sensist philosopher. The elder Mill, Condillac, and the other earlier advocates of Sensism. possessed at least the merit of understanding and frankly attempting to face the real problem for their school. Postulating only those assumptions which were legitimate to them, they sought to explain how, out of sense impressions passively received from without, our illusory belief in a permanent human mind, as well as in a material world, could be produced. The result was, as is virtually admitted by their descendants, a miserable caricature of the observed facts. The modern representative of the school while accepting their fundamental doctrine that the mind is nothing but an aggregate or series of feelings externally awakened, nevertheless ascribes to this mind inherent activity. Such a procedure, however, as was felt, I believe, by the earlier associationists, is incompatible with the essential principles of their system.

Obliviscence. -- From the laws of memory the general conditions of forgetfulness can be easily deduced. The converse of the primary laws of suggestion may be formulated in the statement that events unconnected by either similarity or contiguity with present mental states usually lie beyond the sphere of recall. The correlative of the secondary law is expressed in the proposition that the tendency of an experience to lapse out of memory is in proportion to the feebleness of the original impression and the infrequency of its repetition. The third law of obliviscence enunciates the general fact, that a mental impression becomes obliterated in proportion to the length of time, and the number and vivacity of the other mental states which have intervened since its last occurrence or reproduction.

The phrase, Law of Obliviscence, is also employed by J. S. Mill to describe an important element in the law of "inseparable" association, viz., the general fact that "when a number of ideas suggest one another by association with such certainty and rapidity as to coalesce together in a group all the members of the group which remain long without being attended to have a tendency to drop out of consciousness."^{20} The evanescence of the separate letters and words of a printed page leaving us in possession only of its general purport is the favourite illustration. The phenomenon is merely an instance of the law of inattention. The amount of mental energy, and consequently the depth of the impression, devoted to the individual units is reduced to a minimum, as the whole force of our thought is concentrated on the meaning of the entire paragraph.

Readings. -- On Memory, cf. St. Thomas, Comm. in Arist. De Mem. at Reminisc.; also Sum. i. q. 79. a. 6 and 7; Suarez, De Anima, Lib. iv. c. 10; Hamilton, Metaphysics, Lect. xxx. xxxi.; Carpenter, Mental Physiology, c. x. On the Physiology of Memory, cf. Carpenter, op. cit. pp. 436-448; Ladd, op. cit. Pt. II. c. 10, §§ 15-21; Farges, Le Cerveau et l'Ame, pp. 322-328. Some good remarks on the Materialist theory are to be found in Professor Calderwood's Relations of Mind and Brain, pp. 272-84. On Mental Association, cf. Hamilton, On Reid, notes D**, D***. On the Validity of Memory, J. Rickaby, First Principles, Pt. II. c. vi. On Memory and Empiricism, cf. Ward, Philosophy of Theism, pp. xiv.-xvii. and 64-67. For a collection of curious anecdotes illustrating various aspects of those faculties, see Abercrombie On the Intellectual Powers, Pt. III. sect. I.

{1} Porter, op. cit. § 247.

{2} "Psychology," Encycl. Brit.

{3} Metaph. Vol. II. p. 238.

{4} Confessions, x. c. 19.

{5} Cf. St. Augustine (Epist. ix. ad Neb. n. 3). "Itaque, ea quae ut ita dicam, vestigia sui motus animus figit in corpore, possunt et manere, et quemdam quasi habitum facere, quae latenter, cum agitata fuerint, et contractata secundum agitantis et contractanus voluntatem ingerunt nobis cogitationes, et somnia." Also St. Thomas: "Dicit (Aristoteles) manifestum esse quod oportet intelligere aliquam talem passionem a sensu esse factam in anima et in organo corporis animati, cujus quidem animae memoriam dicimus esse quemdam quasi habitum, quae quidem passio est quasi quaedam pictura. . . . Dicit autem in anima et in parte corporis quia cum hujusmodi passio pertineat ad partem sensitivam quae est actus organici corporis, hujusmodi passio non pertinet ad solam animam sed ad conjunctum." (Comm. De Memoria, i. l. 3.)

{6} Metaphysics, Vol. II. p. III.

{7} Ribot, Diseases of the Memory, p. 10.

{8} Dr. Maudsley, The Physiology of the Mind, p. 513.

{9} Calderwood, The Relations of Mind and Brain. p. 282.

{10} Qu. Disp. de Verit. q. x. a. 2. c.

{11} Cf. Hamilton, Metaph. ii. pp. 225-227.

{12} St. Thomas' rules for the cultivation of memory are a practical embodiment of the Laws of Suggestion and admirably adapted to the development of judicious memory. They are thus well summarized in B. Boedder's Psych. Rat. § 249: -- I. (Similarity). Similitudinibus convenientibus minus consuetis res abstractas tibi declara. II. (Contiguity). Cum ordine dispone quae memoria tenure cupis. III. (Attention). Sollicite et cum affectu addisce, quae cupis rememorari. IV. (Repetition). Quae rememorari tua multum interest ea frequenter meditare. (Sum. 2a 2ae q. 49. a. i. ad 2.)

{13} On this distinction, cf. "Mental Association" by Croom Robertson, Encyc. Brit.

{14} On Reid, note D**.

{15} On Reid, pp. 899, 900.

{16} Causa autem reminiscendi est ordo motuum, qui relinquuntur in anima ex prima impressione ejus, quod primo apprehendimus reminiscentiae contingunt per hoc quod onus motus natus est post alium nobis occurrere." (Ibid.)

{17} "Hoc autem primum, a quo reminiscens suam inquisitionem incipit, quandoque quidem est tempus aliquod notum, quandoque res aliqua nota. (1) Secundum tempus quidem incipit quandoque a nunc, id est a praesenti tempore, procedendo in praeteritum, cujus quaerit, memoriam. . . . Quandoque vero incipit ab aliquo alio tempore . . . et procedit descendendo. . . . (2) Similiter etiam quandoque reminiscitur aliquis incipiens ab aliqoa re cujus memoratur, a qua procedit ad aliam, triplici ratione (a) Quandoque quidem ratione similitudinis; sicut quando aliquid aliquis memoratur de Socrate, et per hoc occurit ei Plato, qui est similis ei in sapientia. (b) Quandoque vero ratione contrarietatis; sicut si aliquis memoretur Hectoris, et per hoc occurrit ei Achilles. (c) Quandoque vero ratione propinquitatis cujuscunque; sicut cum aliquis est memor patris, ei per hoc occurrit ei filius. Et eadem ratio est de quacunque alia propinquitate, vel societatis, vel loci, vel temporis; et propter hoc fit reminiscentia, quia motus horum Se invicem consequuntur. (a) Quorundam enim praemissorum motus sunt idem, sicut praecipue similium; (b) quorundam autem simul, scilicet contrariorum, quia cognito uno contrariorum simul cognoscitur aliud; (c) quandoque vera quidam motus habent partem aliorum, sicut contingit in quibuscunque propinquis, quia in unoquoque propinquorum consideratur aliquid quod pertinet ad alterum, et ideo, illud residuum, quod deest apprehensioni, cum sit parvum, consequitur motum prioris, ut apprehenso primo consequenter occurrat apprehensioni secundum." (St. Thomas, De Mem. l. v.)

{18} Cf. Vives, De Anima, Lib. II. c. De Mem. et Rem. We have not space to quote, but the reader will find a number of passages cited from him in Hamilton's Notes on Reid, pp. 892, 893, 896. 898, 902 908. A very little study even of these extracts will show how familiar to scholastic philosophers were many of the supposed discoveries of Hobbes, Hume, and later associationalist writers.

{19} The terms indissoluble and inseparable are defective even as expressions of the associationist view. It is not maintained that the associated states are absolutely inseparable, since a reversal of previous experience is always possible. The law of irresistible suggestion, advocated as a better title by Mr. Murray, would be a less objectionable phrase to indicate the element of truth contained in the doctrine. The powerful influence of continuous association is indisputable, and the acquired perceptions of the senses which we have discussed in an earlier chapter illustrate its action; but mere association is utterly unable to account for the unity of the mind, or for the necessity of mathematical or metaphysical truths. The phrase, mental chemistry, is also inappropriate and misleading. The chief forms of mental action to which this name has been applied are: (a) The asserted subjective creation of an imaginary material world by the agglutination, solidification, and externalization of sensations and ideas; (b) the production of the alleged illusory necessity pertaining to certain judgments, e.g., mathematical axioms. (a) Now, subjective feelings do not solidify or crystallize into a simulated material object. The true process, as we have shown in chapter vii., is one of growth in the perfection of our knowledge of real things. Successive sensations reveal new qualities of the object, and gradually elaborate cognition. The object, vaguely and obscurely apprehended in the primitive tactual or visual sensation, receives more complete determination by each subsequent impression. (b) That necessary judgments cannot be a result of association will be shown in a future chapter.

{20} Exam. c. xiv. p. 259.