434. Unless man were a subject which is a substance that can serve a source and containant he would be unable to think and will. Any thing that is supposed to exist apart from a substantial subject is nothing. This can be seen from the fact that a man is unable to see without an organ which is the subject of his sight, or to hear without an organ which is the subject of his hearing. Apart from these organs, sight and hearing are nothing and have no existence. The same is true of thought, which is inner sight, and of perception, which is inner hearing; unless these were in substances and from substances which are organic forms and subjects, they would have no existence at all. All this shows that man's spirit as well as his body is in a form, and that it is in a human form, and enjoys sensories and senses when separated from the body the same as when it was in it, and that all the life of the eye and all the life of the ear, in a word, all the life of sense that man has, belongs not to his body but to his spirit, which dwells in these organs and in their minutest particulars. This is why spirits see, hear, and feel, as well as men. But when the spirit has been loosed from the body, these senses are exercised in the spiritual world, not in the natural world. The natural sensation that the spirit had when it was in the body it had by means of the material part that was added to it; but it then had also spiritual sensations in its thinking and willing.