§ 3. The Spatial Significance of Free Movements. — So far, we have dealt only with what may be called restricted movements, movements restricted by the conditions which determine the actual exploration of bodies. But the experiences thus acquired cannot be without effect on free movements. The spatial significance acquired in the exploration of bodies must in some degree cling to analogous movements when they take place without contact with external things. As a matter of fact such movements yield the perception of what may be called geometric configuration, configuration in which the spatial character is not regarded as belonging to any external body, but as the product of our subjective activity. To quote Professor James: "If, with closed eyes, we trace figures in the air with the extended forefinger (the motions may occur from the metacarpal, the wrist, the elbow, or the shoulderjoint indifferently) what we are conscious of in each case, and indeed most acutely conscious of, is the geometric path described by the finger tip. Its angles, its subdivisions, are all as distinctly felt as if seen by the eye; and yet the surface of the fingertip receives no impression at all. ... In persons born blind the phenomenon in question is even more perfect than in ourselves."*

*Principles of Psychology, vol. ii., p. 190.

In these geometric tracings we are making an express experiment, and concentrating attention on the movements of the finger, as such. Under such conditions there is present a very distinct mental image of the path described by the moving finger. It is as if the finger actually left a marked track behind it, and so drew figures in the air. The outline is generally visualised in the case of seeing persons; * the blind presumably image it in the way of passive touch.+ It does not appear however that in ordinary movements, on which we do not expressly concentrate attention, this ideal imagery is distinctly present, or indeed present at all. None the less they still possess a spatial significance. The sweep of a limb, or the movement of the whole body, means extension, differing in amount and direction according to the direction and amount of the movement. This extension is not that of any external body; it is free or empty space. Inasmuch as the presentation of it depends purely on free movement, it ought according to principles laid down in the preceding chapter to lack the character of external reality. This is true of geometric tracings in which attention is wholly concentrated on the free movement itself. But, in general, free space is, as Kant says, a form of the external world. This is so, because free movements are usually not wholly free, but in a certain respect conditioned. They take place in the service of practical ends, and they are useful in this way mainly in so far as they effect a transition from one resisting body to another, or from one part of a resisting body to another part. But the necessity of proceeding from one definite point to another definite point imposes restriction on the amount and direction of the movement. This has been well put by Dr. Bain. "Let us suppose the hand moving between two fixed obstacles, — for example, from one side of a box to another. There is, to commence with, the contact with one side of the box felt more or less as a sense of touch, pressure, and resistance, . . . the abrupt departure from this state is a mark in consciousness, a call to attention; and the mind is awakened to the feeling of movement that follows. After a time, the other side is struck, and the mind is again roused and takes note of the cessation of the movement."* In this way free space acquires the character of a space separating and connecting external bodies and thus itself partakes of external reality.

* Mr. Welton, who is by no means blind, gives me the following account of his own experience. "I can't get the visual image even in this case, or at any rate it is of the vaguest character, and then only seems to arise when I as it were make up my mind I will see it. But it has no colour and I'm not really sure it isn't a touch image after all, — so vague is it. What is plainer far is the touch image, — my finger seems to go round the outside or inside (either at will) boundary of the figure. I certainly seem to feel the figure much more than see it. If I try writing in the air I seem to vaguely apprehend a nearly invisible finger moving, but I don't see a tracing of the letters made after they are made."

+Unless they have lost their sight after the fourth year; in that case they will probably visualise. It is noteworthy that the blind usually talk as if they saw. This arises because they have to use the same language as those who see, and dislike appearing peculiar.

* The Senses and the Intellect, fourth edition, p. 197.