The Essays of Adam Smith

by Adam Smith

461 ‘In a year after seeing,’ adds Mr. Cheselden, ‘the young gentleman being carried upon Epsom-downs, and observing a large prospect, he was exceedingly delighted with it, and called it a new kind of seeing.’ He had now, it is evident, come to understand completely the language of Vision. The visible objects which this noble prospect presented to him did not now appear as touching, or as close upon his eye. They did not now appear of the same magnitude with those small objects to which, for some time after the operation, he had been accustomed, in the little chamber where he was confined. Those new visible objects at once, and as it were of their own accord, assumed both the distance and the magnitude of the great tangible objects which they represented. He had now, therefore, it would seem, become completely master of the language of Vision, and he had become so in the course of a year; a much shorter period than that in which any person, arrived at the age of manhood, could completely acquire any foreign language. It would appear too, that he had made very considerable progress even in the two first months. He began at that early period to understand even the feeble perspective of Painting; and though at first he could not distinguish it from the strong perspective of Nature, yet he could not have been thus imposed upon by so imperfect an imitation, if the great principles of Vision had not beforehand been deeply impressed upon his mind, and if he had not, either by the association of ideas, or by some other unknown principle, been strongly determined to expect certain tangible objects in consequence of the visible ones which had been presented to him. This rapid progress, however, may, perhaps, be accounted for from that fitness of representation, which has already been taken notice of, between visible and tangible objects. In this language of Nature, it may be said, the analogies are more perfect; the etymologies, the declensions, and conjugations, if one may say so, are more regular than those of any human language. The rules are fewer, and those rules admit of no exceptions.

But though it may have been altogether by the slow paces of observation and experience that this young gentleman acquired the knowledge of the connection between visible and tangible objects; we cannot from thence with certainty infer, that young children have not some instinctive perception of the same kind. In him this instinctive power, not having been exerted at the proper season, may, from disuse, have gone gradually to decay, and at last have been completely obliterated. Or, perhaps (what seems likewise very possible), some feeble and unobserved remains of it may have somewhat facilitated his acquisition of what he might otherwise have found it much more difficult to acquire a knowledge of.

That, antecedent to all experience, the young of at least the greater part of animals possess some instinctive perception of this kind, seems abundantly evident. The hen never feeds her young by dropping the 462 food into their bills, as the linnet and thrush feed theirs. Almost as soon as her chickens are hatched, she does not feed them, but carries them to the field to feed, where they walk about at their ease, it would seem, and appear to have the most distinct perception of all the tangible objects which surround them. We may often see them, accordingly, by the straightest road, run to and pick up any little grains which she shows them, even at the distance of several yards; and they no sooner come into the light than they seem to understand this language of Vision as well as they ever do afterwards. The young of the partridge and of the grouse seem to have, at the same early period, the most distinct perceptions of the same kind. The young partridge, almost as soon as it comes from the shell, runs about among long grass and corn; the young grouse among long heath, and would both most essentially hurt themselves if they had not the most acute, as well as distinct perception of the tangible objects which not only surround them but press upon them on all sides. This is the case too with the young of the goose, of the duck, and, so far as I have been able to observe, with those of at least the greater part of the birds which make their nests upon the ground, with the greater part of those which are ranked by Linnæus in the orders of the hen and the goose, and of many of those long-shanked and wading birds which he places in the order that he distinguishes by the name of Grallæ.

The young of those birds that build their nests in bushes, upon trees, in the holes and crevices of high walls, upon high rocks and precipices, and other places of difficult access; of the greater part of those ranked by Linnæus in the orders of the hawk, the magpie, and the sparrow, seem to come blind from the shell, and to continue so for at least some days thereafter. Till they are able to fly they are fed by the joint labour of both parents. As soon as that period arrives, however, and probably for some time before, they evidently enjoy all the powers of Vision in the most complete perfection, and can distinguish with most exact precision the shape and proportion of the tangible objects which every visible one represents. In so short a period they cannot be supposed to have acquired those powers from experience, and must therefore derive them from some instinctive suggestion. The sight of birds seems to be both more prompt and more acute than that of any other animals. Without hurting themselves they dart into the thickest and most thorny bushes, fly with the utmost rapidity through the most intricate forests, and while they are soaring aloft in the air, discover upon the ground the insects and grains upon which they feed.

The young of several sorts of quadrupeds seem, like those of the greater part of birds which make their nests upon the ground, to enjoy as soon as they come into the world the faculty of seeing as completely as they ever do afterwards. The day, or the day after they are dropped, the calf follows the cow, and the foal the mare, to the field; and though 463 from timidity they seldom remove far from the mother, yet they seem to walk about at their ease; which they could not do unless they could distinguish, with some degree of precision, the shape and proportion of the tangible objects which each visible one represents. The degree of precision, however, with which the horse is capable of making this distinction, seems at no period of his life to be very complete. He is at all times apt to startle at many visible objects, which, if they distinctly suggested to him the real shape and proportion of the tangible objects which they represent, could not be the objects of fear; at the trunk or root of an old tree, for example, which happens to be laid by the roadside, at a great stone, or the fragment of a rock which happens to lie near the way where he is going. To reconcile him, even to a single object of this kind, which has once alarmed him, frequently requires some skill, as well as much patience and good temper in the rider. Such powers of sight, however, as Nature has thought proper to render him capable of acquiring, he seems to enjoy from the beginning, in as great perfection as he ever does afterwards.

The young of other quadrupeds, like those of the birds which make their nests in places of difficult access, come blind into the world. Their sight, however, soon opens, and as soon as it does so, they seem to enjoy it in the most complete perfection, as we may all observe in the puppy and the kitten. The same thing, I believe, may be said of all other beasts of prey, at least of all those concerning which I have been able to collect any distinct information. They come blind into the world; but as soon as their sight opens, they appear to enjoy it in the most complete perfection.

It seems difficult to suppose that man is the only animal of which the young are not endowed with some instinctive perception of this kind. The young of the human species, however, continue so long in a state of entire dependency, they must be so long carried about in the arms of their mothers or of their nurses, that such an instinctive perception may seem less necessary to them than to any other race of animals. Before it could be of any use to them, observation and experience may, by the known principle of the association of ideas, have sufficiently connected in their young minds each visible object with the corresponding tangible one which it is fitted to represent. Nature, it may be said, never bestows upon any animal any faculty which is not either necessary or useful, and an instinct of this kind would be altogether useless to an animal which must necessarily acquire the knowledge which the instinct is given to supply, long before that instinct could be of any use to it. Children, however, appear at so very early a period to know the distance, the shape, and magnitude of the different tangible objects which are presented to them, that I am disposed to believe that even they may have some instinctive perception of this kind; though possibly in a much weaker degree than the greater part 464 of other animals. A child that is scarcely a month old, stretches out its hands to feel any little plaything that is presented to it. It distinguishes its nurse, and the other people who are much about it, from strangers. It clings to the former, and turns away from the latter. Hold a small looking-glass before a child of not more than two or three months old, and it will stretch out its little arms behind the glass, in order to feel the child which it sees, and which it imagines is at the back of the glass. It is deceived, no doubt; but even this sort of deception sufficiently demonstrates that it has a tolerably distinct apprehension of the ordinary perspective of Vision, which it cannot well have learnt from observation and experience.

Do any of our other senses, antecedently to such observation and experience, instinctively suggest to us some conception of the solid and resisting substances which excite their respective sensations, though these sensations bear no sort of resemblance to those substances?

The sense of Tasting certainly does not. Before we can feel the sensation, the solid and resisting substance which excites it must be pressed against the organs of Taste, and must consequently be perceived by them. Antecedently to observation and experience, therefore, the sense of Tasting can never be said instinctively to suggest some conception of that substance.

It may, perhaps, be otherwise with the sense of Smelling. The young of all suckling animals, (of the Mammalia of Linnæus,) whether they are born with sight or without it, yet as soon as they come into the world apply to the nipple of the mother in order to suck. In doing this they are evidently directed by the Smell. The Smell appears either to excite the appetite for the proper food, or at least to direct the new-born animal to the place where that food is to be found. It may perhaps do both the one and the other.