_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,
_Your faithful Friend,_
_and obedient Servant._