e line, divisions
corresponding, each to each, with the divisions arbitrarily chosen of
the line once it has been traced. The line traversed by the moving body
lends itself to any kind of division, because it has no internal
organization. But all movement is articulated inwardly. It is either an
indivisible bound (which may occupy, nevertheless, a very long duration)
or a series of indivisible bounds. Take the articulations of this
movement into account, or give up speculating on its nature.

When Achilles pursues the tortoise, each of his steps must be treated as
indivisible, and so must each step of the tortoise. After a certain
number of steps, Achilles will have overtaken the tortoise. There is
nothing more simple. If you insist on dividing the two motions further,
distinguish both on the one side and on the other, in the course of
Achilles and in that of the tortoise, the _sub-multiples_ of the steps
of each of them; but respect the natural articulations of the two
courses. As long as you respect them, no difficulty will arise, because
you will follow the indications of experience. But Zeno's device is to
reconstruct the movement of Achilles according to a law arbitrarily
chosen. Achilles with a first step is supposed to arrive at the point
where the tortoise was, with a second step at the point which it has
moved to while he was making the first, and so on. In this case,
Achilles would always have a new step to take. But obviously, to
overtake the tortoise, he goes about it in quite another way. The
movement considered by Zeno would only be the equivalent of the movement
of Achilles if we could treat the movement as we treat the interval
passed through, decomposable and recomposable at will. Once you
subscribe to this first absurdity, all the others follow.[99]

Nothing would be easier, now, than to extend Zeno's argument to
qualitative becoming and to evolutionary becoming. We should find the
same contradictions in these. That the child can become a youth, ripen
to maturity and decline to old age, we understand when we consider that
vital evolution is here the reality itself. Infancy, adolescence,
maturity, old age, are mere views of the mind, _possible stops_ imagined
by us, from without, along the continuity of a progress. On the
contrary, let childhood, adolescence, maturity and old age be given as
integral parts of the evolution, they become _real stops_, and we can no
longer conceive how evolution is possib