3. And since, in this case, the sensation does not proceed from that body which is seen, but from the body of the living being that perceives, with which the soul is tempered together in some wonderful way of its own; yet vision is produced, that is, the sense itself is informed, by the body which is seen; so that now, not only is there the power of sense, which can exist also unimpaired even in darkness, provided the eyes are sound, but also a sense actually informed, which is called vision. Vision, then, is produced from a thing that is visible; but not from that alone, unless there be present also one who sees. Therefore vision is produced from a thing that is visible, together with one who sees; in such way that, on the part of him who sees, there is the sense of seeing and the intention of looking and gazing at the object; while yet that information of the sense, which is called vision, is imprinted only by the body which is seen, that is, by some visible thing; which being taken away, that form remains no more which was in the sense so long as that which was seen was present: yet the sense itself remains, which existed also before anything was perceived; just as the trace of a thing in water remains so long as the body itself, which is impressed on it, is in the water; but if this has been taken away, there will no longer be any such trace, although the water remains, which existed also before it took the form of that body. And therefore we cannot, indeed, say that a visible thing produces the sense; yet it produces the form, which is, as it were, its own likeness, which comes to be in the sense, when we perceive anything by seeing. But we do not distinguish, through the same sense, the form of the body which we see, from the form which is produced by it in the sense of him who sees; since the union of the two is so close that there is no room for distinguishing them. But we rationally infer that we could not have sensation at all, unless some similitude of the body seen was wrought in our own sense. For when a ring is imprinted on wax, it does not follow that no image is produced, because we cannot discern it unless when it has been separated. But since, after the wax is separated, what was made remains, so that it can be seen; we are on that account easily persuaded that there was already also in the wax a form impressed from the ring before it was separated from it. But if the ring were imprinted upon a fluid, no image at all would appear when it was withdrawn; and yet none the less for this ought the reason to discern that there was in that fluid before the ring was withdrawn a form of the ring produced from the ring, which is to be distinguished from that form which is in the ring, whence that form was produced which ceases to be when the ring is withdrawn, although that in the ring remains, whence the other was produced. And so the [sensuous] perception of the eyes may not be supposed to contain no image of the body, which is seen as long as it is seen, [merely] because when that is withdrawn the image does not remain. And hence it is very difficult to persuade men of duller mind that an image of the visible thing is formed in our sense, when we see it, and that this same form is vision.