The soul and the exterior object do not therefore suffice (to explain sensation); for there would be nothing that suffers. There must therefore be a third term that suffers, that is, which receives the sense-form, or, shape. This third term must "sympathize," or, share the passion of the exterior object, it must also experience the same passion, and it must be of the same matter; and, on the other hand, its passion must be known by another principle; last, passion must keep something of the object which produces it, without however being identical with it. The organ which suffers must therefore be of a nature intermediary between the object which produces the passion and the soul, between the sensible and the intelligible, and thus play the part of a term intermediary between the two extremes, being receptive on one side, making announcements on the other, and becoming equally similar to both. The organ that is to become the instrument of knowledge must be identical neither with the subject that knows, nor with the object that is known. It must become similar to both of them; to the exterior object because it suffers, and to the cognizing soul because the passion which it experiences becomes a form. Speaking more accurately, the sensations operate by the organs. This results from the principle asserted above, that the soul isolated from the body can grasp nothing in the sense-world. As used here, the word "organ" either refers to the whole body, or to some part of the body fitted to fulfil some particular function; as in the case of touch or sight. Likewise, it is easy to see that tools of artisans play a part intermediary between the mind which judges, and the object which is judged; and that they serve to discover the properties of substances. For instance, a (foot) rule, which is equally conformed to the idea of straightness in the mind, and to the property of straightness in the wood, serves the artisan's mind as intermediary to judge if the wood he works be straight. EXCLUSION OF OTHER SIDE ISSUES. We have just demonstrated that sensation belongs exclusively to an embodied soul, and that this implies organs. But we have nothing to do with the question whether the perceived object must be in contact with the organ, or whether the sensation can take place at a distance from the sense-object, by means of an intermediary; as the case of the fire which is located at a distance from our body, without the intermediary's suffering in any manner. It happens again where, empty space serving as intermediary between the eye and the color, one may well ask whether, to see, it suffice to possess the potentiality proper to that organ. But it is sure that sensation is some activity of the soul in a body, or through a body. ARE THE SENSES GIVEN US ONLY FOR THE SAKE OF UTILITY?