e to the other as
possible. This happens in two ways: first by the particles limiting
one another's movement till they all advance in one direction; and,
secondly, in this way, that the particles limit their vertical movements
in virtue of which they are approaching the centre of attraction, till
they all move horizontally--i. e., in parallel circles round the sun as
their centre, no longer intercept one another, and by the centrifugal
force becoming equal with the falling force they keep themselves
constantly in free circular orbits at the distance at which they move.
The result, finally, is that only those particles continue to move in
this region of space which have acquired by their fall a velocity, and
through the resistance of the other particles a direction, by which they
can continue to maintain a FREE CIRCULAR MOVEMENT....

"The view of the formation of the planets in this system has the
advantage over every other possible theory in holding that the origin
of the movements, and the position of the orbits in arising at that same
point of time--nay, more, in showing that even the deviations from the
greatest possible exactness in their determinations, as well as the
accordances themselves, become clear at a glance. The planets are formed
out of particles which, at the distance at which they move, have exact
movements in circular orbits; and therefore the masses composed out of
them will continue the same movements and at the same rate and in the
same direction."(2)

It must be admitted that this explanation leaves a good deal to be
desired. It is the explanation of a metaphysician rather than that of
an experimental scientist. Such phrases as "matter immediately begins to
strive to fashion itself," for example, have no place in the reasoning
of inductive science. Nevertheless, the hypothesis of Kant is a
remarkable conception; it attempts to explain along rational lines
something which hitherto had for the most part been considered
altogether inexplicable.

But there are various questions that at once suggest themselves which
the Kantian theory leaves unanswered. How happens it, for example, that
the cosmic mass which gave birth to our solar system was divided into
several planetary bodies instead of remaining a single mass? Were the
planets struck from the sun by the chance impact of comets, as Buffon
has suggested? or thrown out by explosive volcanic action, in accordance
with the theory of Dr. Darwin? or