ange. If these parts took to changing, we should split them up in
their turn. We should thus descend to the molecules of which the
fragments are made, to the atoms that make up the molecules, to the
corpuscles that generate the atoms, to the "imponderable" within which
the corpuscle is perhaps a mere vortex. In short, we should push the
division or analysis as far as necessary. But we should stop only before
the unchangeable.

Now, we say that a composite object changes by the displacement of its
parts. But when a part has left its position, there is nothing to
prevent its return to it. A group of elements which has gone through a
state can therefore always find its way back to that state, if not by
itself, at least by means of an external cause able to restore
everything to its place. This amounts to saying that any state of the
group may be repeated as often as desired, and consequently that the
group does not grow old. It has no history.

Thus nothing is created therein, neither form nor matter. What the group
will be is already present in what it is, provided "what it is" includes
all the points of the universe with which it is related. A superhuman
intellect could calculate, for any moment of time, the position of any
point of the system in space. And as there is nothing more in the form
of the whole than the arrangement of its parts, the future forms of the
system are theoretically visible in its present configuration.

All our belief in objects, all our operations on the systems that
science isolates, rest in fact on the idea that time does not bite into
them. We have touched on this question in an earlier work, and shall
return to it in the course of the present study. For the moment, we will
confine ourselves to pointing out that the abstract time _t_ attributed
by science to a material object or to an isolated system consists only
in a certain number of simultaneities or more generally of
correspondences, and that this number remains the same, whatever be the
nature of the intervals between the correspondences. With these
intervals we are never concerned when dealing with inert matter; or, if
they are considered, it is in order to count therein fresh
correspondences, between which again we shall not care what happens.
Common sense, which is occupied with detached objects, and also science,
which considers isolated systems, are concerned only with the ends of
the intervals and not with the intervals themselve