her to regard the infinitely complex (and thereby
infinitely well-contrived) organization as a fortuitous concatenation of
atoms, or to relate it to the incomprehensible influence of an external
force that has grouped its elements together. But this complexity is the
work of the understanding; this incomprehensibility is also its work.
Let us try to see, no longer with the eyes of the intellect alone, which
grasps only the already made and which looks from the outside, but with
the spirit, I mean with that faculty of seeing which is immanent in the
faculty of acting and which springs up, somehow, by the twisting of the
will on itself, when action is turned into knowledge, like heat, so to
say, into light. To movement, then, everything will be restored, and
into movement everything will be resolved. Where the understanding,
working on the image supposed to be fixed of the progressing action,
shows us parts infinitely manifold and an order infinitely well
contrived, we catch a glimpse of a simple process, an action which is
making itself across an action of the same kind which is unmaking
itself, like the fiery path torn by the last rocket of a fireworks
display through the black cinders of the spent rockets that are falling
dead.

* * * * *

From this point of view, the general considerations we have presented
concerning the evolution of life will be cleared up and completed. We
will distinguish more sharply what is accidental from what is essential
in this evolution.

The impetus of life, of which we are speaking, consists in a need of
creation. It cannot create absolutely, because it is confronted with
matter, that is to say with the movement that is the inverse of its own.
But it seizes upon this matter, which is necessity itself, and strives
to introduce into it the largest possible amount of indetermination and
liberty. How does it go to work?

An animal high in the scale may be represented in a general way, we
said, as a sensori-motor nervous system imposed on digestive,
respiratory, circulatory systems, etc. The function of these latter is
to cleanse, repair and protect the nervous system, to make it as
independent as possible of external circumstances, but, above all, to
furnish it with energy to be expended in movements. The increasing
complexity of the organism is therefore due theoretically (in spite of
innumerable exceptions due to accidents of evolution) to the necessity
o