ness, and of the local endowments of the senses and moving organs. There is, certainly, a presumption in favour of a contrast, from the essential difference between sense and intellect, notwithstanding their intimate connexion and dependence. Anatomically the two are thought to be separately embodied; the senses being more related to the ganglia of the brain; the intellect to the convoluted hemispheres.

Besides, there are individuals distinguished as learners generally; they may not succeed in all subjects alike, but they have an aptitude for acquirement so extensive as not to be properly referable to endowments of the special senses. When we find a man almost equally accomplished in mechanical art, fine art, language, science, business, we regard the case as coming under general retentiveness, and not under an aggregate of high sense-endowments. Lastly, many of the lower animals, as the dog, have sense-endowments of the first order. If we judge them by the proper test of a sensedelicate discrimination, they will bear comparison with human beings, even in Sight and in Hearing, not to mention their superiority in Smell. But their powers of memory do not correspond; and we must represent the inferiority as attaching to the intellectual region strictly so called, or whatever imparts the retentive power on the whole.

(2.) In the second place, I may advert to the known superiority of early years as regards this force or plasticity. It is impossible to state with any precision the comparative intensity of the adhesive growth at different ages, but there can be no doubt of the fact of its gradually diminishing from infancy to old age. Bodily acquisitions are easiest while the organs are still flexible, apart from the plastic adhesiveness of the brain; hence a maximum age is fixed for admitting recruits into the military service. At the present time, I believe the age of twenty-three is the extreme term of admission. Up to this age, any bodily habit is easily assumed; the moral discipline of obedience is also comparatively easy. But for both the one and the other, the earliest years are the best. We must always take account of the obstruction arising from adverse

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bents and acquisitions. In matters where the bodily and mental system are not pre-occupied, the age of twenty-five is a very plastic age, as for example, in learning businessforms, languages, or science. On the other hand, the voluntary command of the attention is greatest in mature life.

(3.) We remark, finally, that there is a temporary adhesiveness as distinguished from what is enduring or permanent. I may convey a long message from one room to another, but be unable to reproduce it next day. The endurance of the first impression, while the mind is wholly occupied with it, is no surety for its being retained for a week or a month to come.

The illustration in this chapter has been mainly directed upon the enduring acquisitions. We have generally understood the retainability of an impression to mean the power of recalling it at any future time, however remote. But it is necessary to take account of the tendency of all acquisitions to decay by time; the rate of decay being dependent on various circumstances, and chiefly on the decay of the brain. itself. It is observed that the impressions that survive, in extreme old age, are those of early years.

To keep our acquisitions from decaying, it is requisite that they should be occasionally revived. A language acquired in early years may be utterly lost by disuse; whereas, if kept up till mature age, it will be fixed for life. Sustained practice seems particularly necessary in early education children's acquisitions are very liable to decompose, if not kept up and confirmed by new additions. No precise laws have ever been ascertained in this department of the human mind.

The system of cramming is a scheme for making temporary acquisitions, regardless of the endurance of them. Excitable brains, able to command a very great concentration of force upon a subject, will be proportionably impressed for the time being. By drawing upon the strength of the future, we are able to fix temporarily a great variety of impressions, during the exaltation of cerebral power that the

excitement gives. The occasion past, the brain must lie idle for a corresponding length of time, while a portion of the excited impressions will gradually perish away. This system is unfavourable to permanent acquisitions; for these, the force of the brain should be carefully husbanded and temperately drawn upon. Every period of undue excitement and feverish susceptibility is fraught with great waste of the plastic energy of the mind on the whole.

1.

CHAPTER II.

AGREEMENT-LAW OF SIMILARITY.

Present Actions, Sensations, Thoughts, or Emotions tend to revive their LIKE among previous Impressions, or States.

CONTIGUITY joins together things that occur together,

or that are, by any circumstance, presented to the mind at the same time; as when we associate heat with light, a falling body with a concussion. But, in addition to this link of reproductive connexion, we find that one thing will, by virtue of Similarity, recall another separated from it in time, as when a portrait recalls the original.

The second fundamental property of Intellect, termed Consciousness of Agreement, or Similarity, is a great power of mental reproduction, or a means of recovering past mental states. It was noticed by Aristotle as one of the links in the succession of our thoughts.

As regards our knowledge, or perception, of things, the consciousness of Agreement is second only to Discrimination, or the consciousness of Difference. When we know a thing, we do so by its differences and its agreements. Our full knowledge of red, is our having contrasted it with all other colours, and our having compared it with itself and with its various shades. Our knowledge of a chair is made up of our experiences of the distinction between it and other articles of furniture, &c., and of the agreement between it and other chairs. Both modes are involved in a complete act of cognition, and nothing else (except, of course, the Retentiveness implied in the one and the other) is necessary. Our knowledge of man is the sum of the points of contrast between a man and all other things, and the sum of the points of identity on comparing men with one another. Our increase in knowledge

is constantly proceeding in both directions: we note new differences, and also new agreements, among our experiences, object and subject. We do not begin to be conscious till we have the shock of difference; and we cannot make that analysis of our conscious states, called the recognition of plurality, combination, or complication, till we discover agreements, and refer each part of the impression to its like among our previous impressions. To perceive is, properly, to recognize, or identify.

2. Some preliminary explanation of the kind of relationship subsisting between the two principles of Contiguity and Similarity, is requisite in order to guard against mistakes, and especially to prevent misapprehension, as to the separate existence of the two modes of action in the mental framework. When the cohesive link between any two contiguous actions, or images, is confirmed by a new occurrence or repetition, obviously the present impression must revive the sum total of the past impressions, or reinstate the whole mental condition left on the occasion immediately preceding. Thus, if I am disciplining myself in the act of drawing a round figure with my hand, any one present effort must recall the state of the muscular and nervous action, or the precise bent acquired at the end of the previous effort, while that effort had to reinstate the condition at the end of the one preceding, and so on. It is only in this way that repetition can be of any avail in confirming a physical habit, or in forming an intellectual aggregate. But this reinstatement of a former condition by a present act of the same kind, is really and truly a case of the operation of the associating principle of similarity, or of like recalling like; and we here plainly see, that without such recall, the adhesion of contiguous things would be impossible. Hence it would appear, that all through the exposition of Contiguity, the principle of Similarity has been tacitly assumed; we have everywhere taken for granted, that a present occurrence of any object to the view, recalls the total impression made by all the previous occurrences, and adds its own effect to that total.

But, by thus tacitly assuming the power of anything