I am
summing up the fourth chapter of "Matter and Memory". First of all, we
choose between the images, emphasising the strong, extinguishing
the weak, although both have, a priori, the same interest for pure
knowledge; we make this choice above all by according preference to
impressions of touch, which are the most useful from the practical point
of view. This selection determines the parcelling up of matter into
independent bodies, and the artificial character of our proceeding is
thus made plain. Does not science, indeed, conclude in the same way,
showing us--as soon as she frees herself even to a small extent from
common-sense--full continuity re-established by "moving strata," and all
bodies resolved into stationary waves and knots of intersecting fluxes?
Already, then, we shall be nearer pure perception if we cease to
consider anything but the perceptible stuff in which numerically
distinct percepts are cut. Even there, however, a utilitarian division
continues. Our senses are instruments of abstraction, each of them
discerning a possible path of action. We may say that corporal life
functions in the manner of an absorbing milieu, which determines the
disconnected scale of simple qualities by extinguishing most of the
perceptible radiations. In short, the scale of sensations, with its
numerical aspect, is nothing but the spectrum of our practical activity.
Commonly we perceive only averages and wholes, which we contract into
distinct "qualities". Let us disengage from this rhythm what is peculiar
to ourselves.

Above all, let us strive to disengage ourselves from homogeneous space,
this substratum of fixity, this arbitrary scheme of measurement and
division, which, to our greater advantage, subtends the natural,
qualitative, and undivided extension of images. (We usually represent
homogeneous space as previous to the heterogeneous extension of images:
as a kind of empty room which we furnish with percepts. We must reverse
this order, and conceive, on the contrary, that extension precedes
space.) And we shall finally have pure perception in so far as it is
accessible to us.

There is no disputing the absolute value of this pure perception. The
impotence of speculative reason, as demonstrated by Kant, is perhaps,
at bottom, only the impotence of an intelligence in bondage to certain
necessities of the corporal life, and exercised upon a matter which it
has had to disorganise for the satisfaction of our needs. Our