"That there are, in a sense, multiple objects, that one man is distinct from another man, tree from tree, stone from stone, is an indisputable fact; for each of these beings, each of these things, has characteristic properties and obeys a determined law of evolution. But the separation between a thing and its environment cannot be absolutely definite and clear cut; there is a passage by insensible gradations from the one to the other; the close solidarity which binds all the objects of the material universe, the perpetuity of their reciprocal actions and reactions, is sufficient to prove that they have not the precise limits which we attribute to them. Our perception outlines, so to speak, the form of their nucleus; it terminates them at the point where our possible action upon them ceases, where, consequently, they cease to interest our needs. Such is the primary and most apparent operation of the perceiving mind; it marks out divisions in the continuity of the extended, simply following the suggestions of our requirement and the needs of practical life. But in order to divide the real in this manner, we must first persuade ourselves that the real is divisible at will. Consequently we must throw beneath the continuity of sensible qualities, that is to say, beneath concrete extensity, a network, of which the meshes may be altered to any shape whatsoever and become as small as we please; this substratum which is merely conceived, this wholly ideal diagram of arbitrary and infinite divisibility, is homogeneous space."
Matter and Memory by Henri Bergson, p. 277 (Thanks to Alise Piebalga for the reference)
