attention is thus free for other tasks. In this respect analysis by
concepts is the natural method of common-sense. It consists in asking from
time to time what point the object studied has reached, what it has become,
in order to see what one could derive from it, or what it is fitting to say
of it.

But this method has only a practical reach. Reality, which in its essence
is becoming, passes through our concepts without ever letting itself be
caught, as a moving body passes fixed points. When we filter it, we retain
only its deposit, the result of the becoming drifted down to us.

Do the dams, canals, and buoys make the current of the river? Do the
festoons of dead seaweed ranged along the sand make the rising tide? Let
us beware of confounding the stream of becoming with the sharp outline of
its result. Analysis by concepts is a cinematograph method, and it is
plain that the inner organisation of the movement is not seen in the moving
pictures. Every moment we have fixed views of moving objects. With such
conceptual sections taken in the stream of continuity, however many we
accumulate, should we ever reconstruct the movement itself, the dynamic
connection, the march of the images, the transition from one view to
another? This capacity for movement must be contained in the picture
apparatus, and must therefore be given in addition to the views themselves;
and nothing can better prove how, after all, movement is never explicable
except by itself, never grasped except in itself.

But if we take movement as our principle, it is, on the contrary, possible,
and even easy, to slacken speed by imperceptible degrees, and stop dead.

From a dead stop we shall never get our movement again; but rest can very
well be conceived as the limit of movement, as its arrest or extinction;