Here is another important (related) question. If there existed another world and organism which had no relation with our world, and if on the surface of the sky was an eye that was looking, would it perceive this other world at a moderate distance, or would it have no relation thereto? This question will be considered later.[169] Now however we shall give a further proof that the medium has nothing to do with vision. If the air were affected, it would experience a material affection, similar to the figure impressed on wax. In this case, a certain part of the object would be impressed on a certain part of the air; and consequently, the part of the air nearest to the eye would receive a part of the visible object, and this part would be of a size equal to that of the pupil. Now a visible object is seen in its entirety, and all those who are in the air equally see it, whether they behold it from the front, or side, or whether they be one behind the other, without however forming mutual obstacles. This proves that every part of the air contains the entire visible object. This cannot be explained by any corporeal affection, but by higher laws, suitable to the soul, and to the (universal) organism which everywhere responds to itself. MUTUAL RELATION OF THE EYE'S LIGHT AND THE OBJECTIVE LIGHT. 4. What is the mutual relation between the light that emanates from the eye, and the light which is exterior to the eye, and which extends between the eye and the object?[170] Light has no need of air as a medium, unless indeed somebody should undertake to say that there is no light without air, in which case air would be a medium only accidentally. Light itself, however, is an unaffected medium, for there is no necessity here for an affection, but only for a medium; consequently, if light be not a body, there is no need of a body (to act as medium). It might be objected that sight has no need either of a foreign light nor of a medium to see near by, but has need of them for vision at a distance. Later[171] we shall consider whether or not light without air be possible. Now let us consider the first point. INTERMEDIARY LIGHT IS UNNECESSARY, PARTLY BEING AN OBSTACLE.