ones.

past impression the past is recovered and fused with the present instantaneously and surely. So quick and unfaltering is the process that we lose sight of it altogether; we are scarcely made aware of the existence of an associating link of similarity in the chain of sequence. When I look at the full moon, I am instantly impressed with the state arising from all my former impressions of her disc added together; so natural and necessary does this restoration seem that we rarely reflect on the principle implied in it, namely, the power of the new stimulus to set a-going the nervous currents with all the energy acquired in the course of many hundred repetitions of the same visual impetus. But when we pass from perfect to imperfect or partial identity, we are more readily made aware of the existence of this link of attraction between similars, for we find that the restoration sometimes does not take place; cases occur where we fail to be struck with a similitude; the spark does not pass between the new currents and the old dormant The failure in reinstating the old condition by virtue of the present stimulus, is in the main ascribable to imperfect identity. When in some new impression of a thing, the original form is muffled, obscured, distorted, disguised, or in any way altered, it is just a chance if we recognised it; the amount of likeness that is left will have a reviving power, or a certain amount of reinstating energy, while the points of difference or unlikeness will act in resisting the supervention of the old state, and will tend to revive objects like themselves. If I hear a musical air that I have been accustomed to, the new impression revives the old as a matter of course; but if the air is played with complex harmonies and accompaniments, it is possible that the effect of these additions may be to check my recognition of the piece; the unlike circumstances may repel the reinstatement of the old experience more powerfully than the remaining likeness attracts it; and I may either find in it no identity whatever with an air previously known, or I may identify it with something altogether different. If my hold of the essential character of the melody is but feeble, and if I am stunned and confounded with the new accompaniments, there is every likelihood that I shall not

MODES OF UNLIKENESS MIXED UP WITH LIKENESS. 455

experience the restoration of my past hearings of the air intended, and consequently I shall not identify the perform

ance.

4 The obstructives that prevent the revival of the past through similitude may be classed under the two heads of Faintness and Diversity. There are cases where a new impression is too feeble to strike into the old-established track of the same impression and make it alive again, as when we are unable to identify the taste of a very weak solution, or to make out an object in twilight dimness. The most numerous and interesting cases come under the other head of Diversity, or mingled likeness and unlikeness; as when we meet an old acquaintance in a new dress, or in circumstances where we have never seen the same person before. The modes of this diversity are countless and incapable of being classified. We might, indeed, include under diversity the other of the two heads, seeing that faintness implies diversity of degree, if not of any other circumstance; but I prefer considering the obstruction arising from faintness by itself, after which we shall proceed to the larger field of instances constituted by unlikeness in other respects.

5. The difficulty or facility of resuming a past mental condition at the suggestion of a present similitude will depend upon the hold that the past impression has acquired; it is much easier to revive a familiar image than an unfamiliar by the force of a new presentation. We shall, therefore, have to keep this circumstance in view, among others, in the course of our illustration of the law of similarity.

It has to be seriously considered how far mental character, or intellectual peculiarity, affects the power of reviving similars, or of bringing together like things in spite of the repulsion of unlike accompaniments. There is much to be explained in the preferences shown by different minds in the objects that they most readily recal to the present view; which preferences determine varieties of character, such as the scientific and artistic minds. The explanation of these differences. was carried up to a certain point under the Law of Contiguity; but if I am not mistaken there is still a residue referable to

the existence of various modes and degrees of susceptibility to the force of Similarity. From all that I have been able to observe, the two energies of contiguous adhesion and of attraction of similars do not rise and fall together in the character; we may have one feeble and the other strong, in all proportions and degrees of adjustment. I believe, moreover, that there is such a thing as an energetic power of recognising similarity in general, and that this is productive of very striking consequences. Whether I shall be able to impress these convictions upon my readers will depend upon the success of my detailed exposition of this second leading peculiarity of our intellectual nature.

FEEBLENESS OF IMPRESSION.

6. We commence with the case of Faintness or Feebleness in the present, or suggesting, impression considered as an obstacle to the revival of the corresponding previous impression. There is in every instance a certain degree of feebleness that will militate against the efficacy of the present image to reinstate the old track worn by the same image in its former advent. When an extremely faint suggestion in the present answers completely the purpose of reviving the old currents, we must consider that the restoring action of similarity is unusually vigorous in that mind, or for that class of impressions. Thus if by a very feeble solution of salt in water, such as occurs in many land springs, the impression on the tongue is sufficient to revive in one person, and not in another, the past state of mind produced by the tasting of salt, we should naturally remark that in the one the attraction of similars in the matter of taste is more vigorous than in the other. Doubtless there is another circumstance that would make a difference without any positive distinction in the character of the intellectual force of similarity, that is the familiarity with the substance tasted combined with a habit of attending to minute differences, in other words a concentration of the mind upon the effect; but where this difference, due to professional habits, does not exist, the only interpretation we can put upon the

REINSTATEMENT BY FEEBLE IMPRESSIONS.

457

circumstance is that now supposed,-an inequality in the power of reinstating a past condition of mind by a similar one present. If without any express education, one person can discern common salt in a solution when present at the rate of eight grains to the gallon, while another person requires twelve grains per gallon to be present, and a third twenty, then these numbers would roughly express the strength of the force of similarity on the matter of Taste in the three persons respectively. We cannot infer from this that in other impressions, as in Smell or Hearing, there would be the same distinction in these three parties, inasmuch as the character of the special organ counts for something. The structure of the tongue may be such as to make a slight taste in one person as impressive in the conscious mind as a stronger taste in another person: while in order to ascribe the difference to an intellectual peculiarity, such as the intensity of the attraction of similars, we should have to suppose the same solution to yield an equal sensation or an equal intensity of the feeling of taste.

7. Such is a general example taken at random to show what is meant by the revival of impressions under the impediment that feebleness puts in the way. I might go systematically through the Sensations of the various Senses to gather illustrations of the same fact. (Movements apart from Sensations do not furnish cases in point). In the various sensations of Organic Life, there occur examples of difficult reinstatement, through feebleness of the suggesting sensation. I may experience a certain uneasy sensation, which I cannot describe or recognise, because of its being too faintly marked to reproduce the old accustomed impression of the same thing. It may be a derangement of the stomach, or the liver, or the brain, such as I have experienced before and possess a durable conception of, but being too little prominent to strike into the old track it reminds me of nothing, and I cannot tell what it is. By and by it increases somewhat, and becomes powerful enough to reinstate some likeness of it in the past, and I then know its character. If on the one hand, the feeling is located in an organic tissue easily inflamed into sensibility by a light

impression, or if on the other, the general power of similarity is comparatively strong, and the recognition of organic pains and pleasures rapid and easy, a very slight manifestation makes me at once aware of what is happening to me. This keen organic sensibility may be noted as a peculiarity of some constitutions, making the individual extremely self-conscious, in the sense of being alive to every passing change of organic state; generating hypochondria and the alternation of fears and hopes regarding one's bodily welfare. The peculiarity will be occasionally found rising to a morbid extreme; as when the individual never passes an hour without solicitude on the matter of health and mortality. Obtuseness of feeling to what is going on within the various bodily parts is a defect fraught with dangerous neglect; while on the other hand a needless amount of distress and a needless waste of precaution may be the result of too much sensibility, whether this have its origin in the sense or in the intellect.

8. I have already cited an example from Taste. There would be no material difference in the circumstances of a case of Smell. When a very faint odour is recognised or identified, this shows that notwithstanding the faintness of the impression the previous sum total of the same smell has been brought back. If two persons be subjected to the same odour, as in walking through a garden, and if one recognises it while the other feels it not, the difference is to be referred to one or more of the three main circumstances involved in such a perception, namely, greater familiarity with the odorous substance, greater acuteness of the organ, or greater force of the attraction of similars. If both parties are known to be alike familiar with the supposed odour, we must refer the difference to one of the two remaining circumstances; and if by some further test we could find that they had equal delicacy of organ, that is, if it could be shown that the same smell caused a nearly equal force of sensation or consciousness, the explanation would be thrown upon the last of the three considerations, the intellectual force of similarity, which we are now bent upon tracing out. If a person is not remarkable for being excited, agitated, in other words made highly sensitive, by