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three hundred sail belonging to the island, he would tell the name of each one as she approached with unerring certainty, while she was still at such a distance as to present to a common eye only a confused white blur upon the clear horizon.' There are numerous instances to the same effect, occasioned by the situations in which men are placed, and the calls for the frequent exercise of the sight. The almost intuitive vision of the skilful engineer is, beyond doubt, in most cases merely a habit. He has so often fixed his eye upon those features in a country which have a relation to his peculiar calling, that he instantly detects the bearing of a military position, its susceptibility of defence, its facilities of approach and retreat, &c.
No man is born without the sense of touch, but many are born without the sense of hearing; and, wherever this is the case, we are entitled to look for habits of sight. Persons under such circumstances naturally and necessarily rely much on the visual sense, whatever aids may be had by them from the touch. Hence habits; and these imply increased quickness and power, wherever they exist. It is a matter of common remark, that the keenness of visual observation in the DEAF and DUMB is strikingly increased by their peculiar circumstances. Shut out from the intercourse of speech, they read the minds of men in their movements, gestures, and countenances. They notice with astonishing quickness, and apparently without any effort, a thousand things which escape the regards of others. This fact is undoubtedly the foundation of the chief encouragement which men have to attempt the instruction of that numerous and unfortunate class of their fellow-beings. They can form an opinion of what another says to them by the motion of the lips; and sometimes even with a great degree of accuracy. That this last, however, is common, it is not necessary to assert; that it is possible, we have the testimony of well-authenticated facts. In one of his letters, Bishop Burnet mentions to this effect the case of a young lady at Geneva.-“ At two years old," he says, “it was perceived that she had lost her hearing, and ever since, though she hears great noises, yet hears nothing of what is said to her; but, by
observing the motion of the lips and mouths of others, she acquired so many words, that out of these she has formed a sort of jargon in which she can hold conversation whole days with those who can speak her language. She knows nothing of what is said to her, unless she sees the motion of their lips that speak to her; one thing will appear the strangest part of the whole narrative. She has a sister with whom she has practised her language more than with anybody else, and in the night, by laying her hand on her sister's mouth, she can perceive by that what she says, and so can discourse with her in the dark." (London Quarterly Review, vol. xxiv, p. 399.)
Such are the views which have been opened to us in considering the law of HABIT in connexion with the senses; and we may venture to say with confidence, that they are exceedingly worthy of notice. There are two suggestions which they are especially fitted to call up. They evince the striking powers of the human mind, its irrepressible energies, which no obstacles can bear down. They evince also the benevolence of our Creator, who opens in the hour of misery new sources of comfort, and compensates for what we have not, by increasing the power and value of what we have. $ 54. Sensations may possess a relative, as well as positive increase of
power. There remains a remark of some importance to be made in connexion with the general principle which has been brought forward, and as in some measure auxiliary to it; for it will help to explain the more striking instances of habits, if any should imagine that the fact of mere repetition is not sufficient to account for them. Our sensations and perceptions may acquire not only a direct and positive, but a relative and virtual increase of power.
This remark is thus explained. We shall hereafter see the truth of an important principle to this effect, that there will be a weakness of remembrance in any particular case in proportion to the want of interest in it. Now hundreds and thousands of our sensations and perceptions are not remembered, because we take no interest in them. Of course they are the same, relatively to our amoụnt of
knowledge and our practice, as if they had never existed at all. But when we are placed in some novel situation, or when, in particular, we are deprived of any one of the senses, the pressure of our necessities creates that interest which was wanting before. Then we delay upon, and mark, and remember, and interpret a multitude of evanescent intimations which were formerly neglected. The senses thus acquire a very considerable relative power and value. And in order to make out a satisfactory explanation of some instances of habits, it is perhaps necessary that this relative increase should be added to the direct and positive augmentation of vigour and quickness resulting from mere repetition or exercise.
$ 55. Of habits as modified by particular callings and arts. Hitherto it has been our chief object to examine habits in their relation to the senses separately; it is proper also to take a general view of them, as formed and modified by the particular callings and employments of men. Habits of perception are frequently formed under such circumstances, where all the senses are not only possessed, but where they exist with their ordinary aptitudes and powers.-In consequence of the habits which he has been called upon to form by his particular situation, a farmer of a tolerable degree of experience and discernment requires but a slight inspection, in order to give an opinion on the qualities of a piece of land, and its suitableness for a settlement. A skilful printer will at once notice every, thing of excellence or of deficiency in the mechanical execution of a printed work.—The same results are found in all who practise the fine arts. An experienced painter at once detects a mannerism in colouring, combinations and contrasts of light and shade, and peculiarities of form, proportion, or position, which infallibly escape a person of more limited experience.
Dr. Reid speaks on this subject in the following characteristic manner.—“ Not only men, but children, idiots, and brutes, acquire by habit many perceptions which they had not originally. Almost every employment in life hath perceptions of this kind that are peculiar to it. The shepherd knows every sheep of his flock, as we do our
acquaintance, and can pick them out of another flock one by one. The butcher knows by sight the weight and quality of his beeves and sheep before they are killed. The farmer perceives by his eye very nearly the quantity of hay in a rick, or of corn in a heap.
The sailor sees the burden, the built, and the distance of a ship at sea, while she is a great way off. Every man accustomed to writing, distinguishes acquaintances by their handwriting, as he does by their faces. And the painter distinguishes, in the works of his art, the style of all the great masters. In a word, acquired perception is very different in different persons, according to the diversity of objects about which they are employed, and the application they bestow in observing them."* $ 56. The law of habit considered in reference to the perception of the
outlines and forms of objects. Before leaving the subject of Habit, considered as influencing Sensation and Perception, there is one other topic which seems to be entitled to a brief notice; we refer to the manner in which we perceive the outlines and forms of bodies. In discussing the subject of Attention, Mr. Stewart, in connexion with his views on that subject, introduces some remarks in respect to vision. He makes this supposition, That the eye is fixed in a particular position, and the picture of an object is painted on the retina. He then starts this inquiry : Does the mind perceive the complete figure of the object at once, or is this perception the result of the various perceptions we have of the different points in the outline ?--He holds the opinion, that the perception is the result of our perceptions of the different points in the outline, which he adopts as naturally consequent on such views, as the following: The outline of every body is made up of points or smallest visible portions; no two of these points can be in precisely the same direction; therefore every point by itself constitutes just as distinct an object of attention to the mind, as if it were separated by some interval of empty space from all the other points. The conclusion therefore is, as every body is made up of parts, and as the perception of the figure of the whole object implies a knowledge of the relative situation of the different parts with respect to each other, that such perception is the result of a number of different acts of attention.
* Reid's Inquiry into the Human Mind, chap. vi., 0 20.
But if we adopt this view of Mr. Stewart, it is incumbent upon us to show how it happens that we appear to see the object at once. The various facts which have been brought forward in this chapter appear to furnish us with a solution of this question. The answer is, that the acts of perception are performed with such rapidity, that the effect with respect to us is the same as if it were instantaneous. A habit has been formed; the glance of the mind, in the highest exercise of that habit, is indescribably quick; time is virtually annihilated; and separate moments are to our apprehension of them crowded into one.
0 57. Notice of some facts which favour the above doctrine. Some persons will probably entertain doubts of Mr. Stewart's explanation of the manner in which we perceive the outlines of objects; but there are various circumstances which tend to confirm it. When we look for the first time on any object which is diversified with gaudy colours, the mind is evidently perplexed with the variety of perceptions which arise; the view is indistinct, which would not be the case if there were only one, and that an immediate perception. And even in paintings, which are of a more laudable execution, the effects at the first perception will be similar.
But there is another fact which comes still more directly to the present point. We find that we do not have as distinct an idea, at the first glance, of a figure of a hundred sides, as we do of a triangle or square. evidently should, if the perception of visible figure were the immediate consequence of the picture on the retina, and not the combined result of the separate perceptions of the points in the outline. Whenever the figure is very simple, the process of the mind is so very rapid that the perception seems to be instantaneous. But when the sides are multiplied beyond a certain number, the interval of time necessary for these different acts of attention