Appendix 25.

(708) [Extrasubjective perception of bodies]

When we had to establish the first, substantial difference between our own body and bodies different from our own, we found that the former was perceived along with us as sentient subject, while the latter were perceived simply as forces different from the subject. This difference was proved by: 1. a fact revealed by consciousness - when we say 'fact' we mean 'something self-evident', and therefore 'certain'; 2. use of the theory of perception already outlined (cf. 528-536), and of the principles of substance and cause (cf. 567-569).

However, our body can be perceived extrasubjectively, just as any other body can be. In this case, if we perceive our body as an extrasubjective term of our sense-faculty, we can discover secondary, but nevertheless important differences, enabling us once again to distinguish it from external bodies. This way of distinguishing our own body (considered as different from us as subject) from external bodies, supposes the truth about an extrasubjective term of our sense-faculty. There was, however, no need of this as long as the distinction between our own and other bodies depended upon the substantial difference between subject and that which is extrasubjective.

Three differences may be noted between the extrasubjective perception of our own and external bodies. These differences show that our own body is quite distinct from any external body. Galluppi sets out the differences as follows:

First difference:

If your right hand is warm, and your left cold, and you bring them into contact, you will feel the same 'self' in them both. Myself which feels the warmth of the right hand is the same as that which feels the cold of the left. Myself, therefore, seems to exist in both hands. But if you touch a lump of metal with one hand, you will feel myself in the hand without feeling it in the metal. It does not seem to exist in the lump of metal, which is extraneous to myself. Contact between the two hands furnishes two sensations; contact with the metal only one. Myself looks upon right and left hands as parts of its own body because it has a touch-feeling in both; it looks upon the lump of metal as an external body because it has a touch-feeling of the metal, but not in the metal. Myself regards as its own the body which it feels, and in which it seems to feel or to exist; it regards as external to itself a body which it feels, but in which it does not seem to feel or exist.

Second difference:

If you want to move your arm, you do so from within, immanently. But the lump of metal will not move simply because you want it to. First, you have to move your hand towards it, and then move the lump by moving your hand. Myself regards as its own the body which it can move by willing to do so; it regards as external any body whose movement does not depend upon its act of will.

Third difference:

You can move the lump of metal to a place where it no longer acts upon any of your senses. But you cannot do this with your own body. At least while you are awake, it is impossible to avoid its action. Myself regards as its own, therefore, that body which is unceasingly present to it; it regards as external any body ceasing to modify it or not present to it.

Galluppi concludes from these observations that we can distinguish our own from external bodies by means of sight and touch. But both senses perceive extrasubjectively, and I am not satisfied with showing a difference between our own body and external bodies as differing terms of sight and touch. We must also recognise that our own body pertains to ourselves as subject, while external bodies are purely extrasubjective. This is the basic difference beteen them.

Nevertheless, the three facts indicated by Galluppi do help considerably to underline the distinction between a subject and something different from the subject, if we take their analysis one step further. In the first of the three differences, where the hand feels itself as sentient, we find a subject, while the lump of metal which is only felt and does not feel itself, is indicative of something different from the subject. In the second difference, the movement that I want to carry out through my hand can be perceived not only with sight and touch, but principally through interior feeling and consciousness, which draw attention to the subject. The movement I impart to the lump of metal is clearly noted only through sight and touch indicating something different from the subject. In the third difference, I feel my body united with me wherever I go, not because I see it or touch it, but principally through interior consciousness, which indicates me as its subject. The distance of external bodies is brought home to me by touch or the other senses indicating that these bodies are extrasubjective terms of my feeling powers.