Your Faithful Friend
and Servant.
[1] Ch. 27.
[XX.]
MADAM,
Some perhaps will question the truth or probability of my saying, that Light is a Body, objecting that if light were a body, when the Sun is absent or retires under our Horizon, its light would leave an empty place, or if there were no empty place but all full, the light of the Sun at its return would not have room to display it self, especially in so great a compass as it doth, for two bodies cannot be in one place at one time. I answer, all bodies carry their places along with them, for body and place go together and are inseparable, and when the light of the Sun is gone, darkness succeeds, and when darkness is gone, light succeeds, so that it is with light and darkness as with all Creatures else; For you cannot believe, that if the whole World were removed, there would be a place of the world left, for there cannot be an empty nothing, no more then there can be an empty something; but if the world were annihilated, the place would be annihilated too, place and body being one and the same thing; and therefore in my opinion, there be no more places then there are bodies, nor no more bodies then there are places.
Secondly, They will think it absurd that I say, the eye can see without light; but in my opinion it seems not absurd, but very rational, for we may see in dreams, and some do see in the dark, not in their fancy or imagination, but really; and as for dreams, the sensitive corporeal motions make a light on the inside of the organ of sight really, as I have declared in my former Letter. But that we do not see ordinarily without exterior Light, the reason is, that the sensitive Motions cannot find the outward objects to pattern out without exterior light, but all perception doth not proceed from light, for all other perception besides animal sight requires not light. Neither in my opinion, doth the Perception of sight in all Creatures but Animals, but yet Animals do often see in the dark, and in sleep: I will not say but that the animate matter which by self-motion doth make the Perception of light with other perceptive Figures, and so animal perceptive light may be the presenter or ground perceptive figure of sight; yet the sensitive corporeal motions can make other figures without the help of light, and such as light did never present: But when the eye patterns out an exterior object presented by light, it patterns also out the object of light; for the sensitive motions can make many figures by one act, not onely in several organs, but in one organ; as for example, there is presented to sight a piece of Imbroydery, wherein is silk, silver and gold upon Sattin in several forms or figures, as several flowers, the sensitive motions streight by one and the same act, pattern out all those several figures of flowers, as also the figures of Silk, Silver, Gold and Sattin, without any pressure of these objects, or motions in the medium, for if they all should press, the eye would no more see the exterior objects, then the nose, being stopt, could smell a presented perfume.
Thirdly, They may ask me, if sight be made in the eye, and proceeds not from the outward object, what is the reason that we do not see inwardly, but outwardly as from us? I answer, when we see objects outwardly, as from us, then the sensitive motions work on the outside of the organ, which organ being outwardly convex, causes us to see outwardly, as from us, but in dreams we see inwardly; also the sensitive motions do pattern out the distance together with the object: But you will say, the body of the distance, as the air, cannot be perceived, and yet we can perceive the distance; I answer, you could not perceive the distance, but by such or such an object as is subject to your sight; for you do not see the distance more then the air, or the like rare body, that is between grosser objects; for if there were no stars, nor planets, nor clouds, nor earth, nor water, but onely air, you would not see any space or distance; but light being a more visible body then air, you might figure the body of air by light, but so, as in an extensive or dilating way; for when the mind or the rational matter conceives any thing that hath not such an exact figure, or is not so perceptible by our senses; then the mind uses art, and makes such figures, which stand like to that; as for example, to express infinite to it self, it dilates it parts without alteration, and without limitation or circumference; Likewise, when it will conceive a constant succession of Time, it draws out its parts into the figure of a line; and if eternity, it figures a line without beginning, and end. But as for Immaterial, no mind can conceive that, for it cannot put it self into nothing, although it can dilate and rarifie it self to an higher degree, but must stay within the circle of natural bodies, as I within the circle of your Commands, to express my self
Madam,