p The universal character of the motion of matter was recognised by pre-Marxist materialists, but they interpreted it in a narrow, metaphysical way. They did not associate motion with change, development of bodies, and often conceived it only as mechanical displacement in space.

p Dialectical materialism does not reduce the diversity of forms of motion to a single mechanical or any other form, but associates motion with change, development of bodies, the coming into being of the new and the passing away of the old. Motion is understood by dialectical materialism as any change, as change in general which encompasses all the processes transpiring in the Universe—from the simplest mechanical displacement to such an extremely complex process as human thinking.

p Matter exists only in motion, through which it manifests or reveals itself. The facts of daily life, the development of science and practice have given convincing proof of this.

p Let us take, for example, the atom. It exists as a definite material body only in so far as the elementary particles forming it are in constant motion. Outside of the motion of these particles the atom could not exist, nor could there be any other body without motion. As soon as metabolic interchange between the organism and the environment ceases (this .is also a form of motion), the living organism perishes.

p Due to motion material bodies manifest themselves, act on our sense organs. The Sun, for example, constantly irradiates countless moving particles into cosmic space. When they reach the Earth, these particles act on our sense organs and make the existence of the Sun known to us. If it were not for the movement of these particles we would not even suspect the Sun’s existence; after all, the Sun is about 150 million kilometres away from the Earth.

p Similarly, all other material bodies exist, manifest themselves only in motion. Not only elementary particles in atoms are in motion, but also the atoms in molecules and the molecules in bodies. The whole vast mass of terrestrial 47 and cosmic bodies is in motion. Likewise,living organisms and social life undergo changes. It is impossible to find a single particle of the material world which does not move or change.

Motion is thus a form of the existence of matter, its inalienable attribute. “Motion is the mode of existence of matter. Never anywhere has there been matter, without motion, nor can there be,”  [47•*  Engels wrote.