the others perceive quality. The first are almost caught up
in the running-gear of things; the others react, and the tension of
their faculty of acting is probably proportional to the concentration of
their faculty of perceiving. The progress goes on even in humanity
itself. A man is so much the more a "man of action" as he can embrace in
a glance a greater number of events: he who perceives successive events
one by one will allow himself to be led by them; he who grasps them as
a whole will dominate them. In short, the qualities of matter are so
many stable views that we take of its instability.

Now, in the continuity of sensible qualities we mark off the boundaries
of bodies. Each of these bodies really changes at every moment. In the
first place, it resolves itself into a group of qualities, and every
quality, as we said, consists of a succession of elementary movements.
But, even if we regard the quality as a stable state, the body is still
unstable in that it changes qualities without ceasing. The body
pre-eminently--that which we are most justified in isolating within the
continuity of matter, because it constitutes a relatively closed
system--is the living body; it is, moreover, for it that we cut out the
others within the whole. Now, life is an evolution. We concentrate a
period of this evolution in a stable view which we call a form, and,
when the change has become considerable enough to overcome the fortunate
inertia of our perception, we say that the body has changed its form.
But in reality the body is changing form at every moment; or rather,
there is no form, since form is immobile and the reality is movement.
What is real is the continual _change of_ form: _form is only a snapshot
view of a transition_. Therefore, here again, our perception manages to
solidify into discontinuous images the fluid continuity of the real.
When the successive images do not differ from each other too much, we
consider them all as the waxing and waning of a single _mean_ image, or
as the deformation of this image in different directions. And to this
mean we really allude when we speak of the _essence_ of a thing, or of
the thing itself.

Finally things, once constituted, show on the surface, by their changes
of situation, the profound changes that are being accomplished within
the Whole. We say then that they _act_ on one another. This action
appears to us, no doubt, in the form of movement. But from the mobility
of the move