« VorigeDoorgaan »
indeed to suppose that the mind ever actually exists in the condition that we have imagined for it. From the moment of birth, it possesses the command of the voluntary movements of the body, and this power we shall see opens to it, from the commencement of its career, a range of activity from which by our hypothesis, it was altogether excluded. We have placed it in its hypothetical imprisonment, not as forming a portion of the actual history of any human being, but solely that we might the more easily disentangle the elements of its powers from their more complicated phenomena.
END OF BOOK I.
PERCEPTION, AND THE PHENOMENA DEPENDENT UPON IT.
WE are now to raise the mind, which we have been contemplating, to a higher state of existence than that which our hypothesis has assigned to it, and to open to it a wider field for the exercise of its faculties. The step by which this is to be effected, is giving it such command of the movements of the body, in which it resides, as we possess,- -a power over those of its motions which are called voluntary motions, as distinguished from those motions which proceed independently of its will.
An infant, from its birth, and independently of all experience, moves those members of its body which are under the control of its will, wittingly. It stretches out its hand, or its foot, and draws it in again, conscious of what it does. This is rendered evident by the fact which we have formerly noticed, that an infant which has once sucked the breast in a reclining posture, will turn its head to the same side on which it lay when it first enjoyed its natural beverage, and form its lips into a round aperture as when they enclosed the nipple, as an indication of its desire of a repetition of the same enjoyment, and of its expectation of receiving it as when it was in the same posture. We have observed a very young infant, we dare not say how few weeks old, for we took no note of it, bring his hand over an itching sore behind his ear, manifesting how early he had acquired the power of directing his hand wittingly, and his knowledge of the direction in which the sore lay that was annoying him. We conceive it unnecessary to offer any further proof of
the fact, that from our earliest infancy, independently of all reasoning and of all inferences from experiment, we move those members of the body which are placed under the control of the mind, designedly and consciously of what we do. Now this fact in our constitution produces the most important results. It is not necessary, indeed, to these results, that this consciousness of power over the muscles of the body, should be innate; it is manifest that it is very early acquired, and all that is necessary for our purpose is that we come to possess it. We proceed to describe the immediate results of this power.
WE have seen that no conception or notion of anything external to the mind could have been communicated by mere sensation. In the state in which in the former book we supposed it to be placed, it was exposed to various influences from the external world through the senses; but it never, in that condition, could have discovered that there was an external world. Its sensations would in such circumstances come and go, but it could never discover how, or from what cause; and they would leave behind them some effect, some impression, as it is figuratively called, that would cause them to be revived in the mind under certain circumstances, and to lay the foundation of many interesting operations, but all without any conception of objects external to itself, which gave beginning to these sensations and operations.
How, then, does the mind acquire its knowledge of external objects? The first, and, in some sense, natural supposition is, that the senses discern these objects,hear, see, taste, smell, feel them; just as it is the first
and natural account that we give of the vicissitudes of day and night, that the sun rises in the east, and passes over to the west, and there sinks beneath the horizon. As more accurate observation, however, has discovered that the sun does not rise nor set, but that its appearing to do so arises from the motion of the earth, so it has been discovered that we hear, see, taste, smell, and feel, only our own sensations, and not the external things that cause the sensations; and that our inferring the existence of external objects from our sensations is the result of experience. Some of the ancient philosophers imagined that all external objects gave out certain subtile emanations images of themselves, which they called ideas, which entered the organs of sense, and by means of which ideas the mind perceived the external objects. That theory has been long abandoned. More recently, it has been thought that the notion of external objects was conveyed by the sense of touch, and that the mind intuitively inferred the existence, and what have been called the primary qualities, of objects, such as extension, form, &c., from the sensations received by this sense. We have seen, however, that the sense of touch would not of itself convey this notion, any more than any of the other senses; yet this sense is more nearly connected with the discovery of external objects than any or all of the other senses.
The following seems to be the history of this most important of all discoveries.
The infant has power to move various parts of its body. We shall confine ourselves at present to the hands. In stretching out his hand, he encounters resistance; he draws it in, stretches it out again, and is stopped by the same resistance: this conveys the idea of a vacant space and something beyond it. He draws in his hand and
* Some metaphysicians suppose that space is a notion in the mind anterior to all experience, that when an infant stretches out his hand he is conscious that the movement is in space. We are not disposed very keenly to dispute what may be in the mind of an infant, but only
touches some part of his own body; here he meets resistance as before, but there is now a double sensation, the sensation from the nerves of his hand, and the sensation from those of the part of the body which his hand touched. By repeated experiments of this kind, he learns to distinguish between his own body and other objects, and also to know that other objects may be at some distance from him-that there is a vacant space between him and them. He grasps some object, and finds himself resisted in attempting to shut his hand; he opens his hand, the object that he grasped is removed; he shuts it again, and finds no resistance till he meets part of his own hand, which he learns to distinguish from the extraneous object by the double sensation. He lays his hand on a hard substance, and finds himself peremptorily prevented from moving it farther in that direction; but he finds that he can move it along the surface of a hard object to the right or left, forward or backward, till he comes to the ends or sides of it, and then the resistance ceases at once, and his hand drops; he lifts it, finds the object again, moves his hand over it till he gets to the edges of it, and thus has a kind of rough measurement of the extent of its surface in various directions. As he proceeds with his investigations, he say, that, having weighed the arguments for that opinion, as far as we could understand them, we are not convinced by them, and still believe that our notion of space is the result of experience. We must admit, however, that the notion of space may be, as Sir William Hamilton distinguishes, although not innate, yet native. The infant moves in the womb; are its motions voluntary, and is it conscious of these motions being in any particular direction? If so, it must receive the notions of matter and space there. Are its motions arrested by the parietes of its receptacle, and is it conscious of their being so arrested? Then it may be born with the conception of a non ego, or something different from itself. Still we should conceive it more probable that the notion of matter, space, and a non ego, is derived from its voluntary motions, than that it has an innate notion of space, and moves its limbs, in consequence of that innate notion, in a certain direction. For a notice of Kant's inferences, from what he regards as necessary cognitions or modes of thought, we refer to Note B in the Appendix.