23. Motion proves a vacuum.
But not to go so far as beyond the utmost bounds of body in the universe, nor appeal
to God's omnipotency to find a vacuum, the motion of bodies that are in our view and neighbourhood seems to me
plainly to evince it. For I desire any one so to divide a solid body, of any dimension he pleases, as to make it
possible for the solid parts to move up and down freely every way within the bounds of that superficies, if there be
not left in it a void space as big as the least part into which he has divided the said solid body. And if, where the
least particle of the body divided is as big as a mustard-seed, a void space equal to the bulk of a mustard-seed be
requisite to make room for the free motion of the parts of the divided body within the bounds of its superficies,
where the particles of matter are 100,000,000 less than a mustard-seed, there must also be a space void of solid
matter as big as 100,000,000 part of a mustard-seed; for if it hold in the one it will hold in the other, and so on in
infinitum. And let this void space be as little as it will, it destroys the hypothesis of plenitude. For if there can be a
space void of body equal to the smallest separate particle of matter now existing in nature, it is still space without
body; and makes as great a difference between space and body as if it were μέγα χάσμα, a distance as wide as
any in nature. And therefore, if we suppose not the void space necessary to motion equal to the least parcel of the
divided solid matter, but to 1/10 or 1/1000 of it, the same consequence will always follow of space without matter.
