particle, so accurately placed in
the middle, as to be always equally attracted on all sides, and,
thereby, continue without motion, seems to me a supposition fully as
hard as to make the sharpest needle stand upright upon its point on a
looking-glass. For, if the very mathematical centre of the central
particle be not accurately in the very mathematical centre of the
attractive power of the whole mass, the particle will not be attracted
equally on all sides. And much harder is it to suppose all the
particles, in an infinite space, should be so accurately poised, one
among another, as to stand still in a perfect equilibrium. For I reckon
this as hard as to make not one needle only, but an infinite number of
them, (so many as there are particles in an infinite space,) stand
accurately poised upon their points. Yet I grant it possible, at least,
by a divine power; and, if they were once to be placed, I agree with
you, that they would continue in that posture without motion, for ever,
unless put into new motion by the same power. When, therefore, I said,
that matter evenly spread through all space, would convene, by its
gravity, into one or more great masses, I understand it of matter not
resting in an accurate poise."

Let not it be thought irreverence to this great name, if I observe, that
by "matter evenly spread" through infinite space, he now finds it
necessary to mean "matter not evenly spread." Matter not evenly spread
will, indeed, convene, but it will convene as soon as it exists. And, in
my opinion, this puzzling question about matter, is only, how that could
be that never could have been, or what a man thinks on when he thinks on
nothing.

Turn matter on all sides, make it eternal, or of late production, finite
or infinite, there can be no regular system produced, but by a voluntary
and meaning agent. This the great Newton always asserted, and this he
asserts in the third letter; but proves, in another manner, in a manner,
perhaps, more happy and conclusive.

"The hypothesis of deriving the frame of the world, by mechanical
principles, from matter evenly spread through the heavens, being
inconsistent with my system, I had considered it very little, before
your letter put me upon it, and, therefore, trouble you with a line or
two more about it, if this comes not too late for your use.

"In my former, I represented, that the diurnal rotations of the planets
could not be derived from gravity, but required a di