Space and Time
Recognising the existence of objective reality, i.e.., matter in motion, independently of our mind, materialism must also inevitably recognise the objective reality of time and space, in contrast above all to Kantianism, which in this question sides with idealism and regards time and space not as objective realities but as forms of human understanding. The basic difference between the two fundamental philosophical lines on this question too is quite clearly recognised by writers of the most diverse trends who are at all consistent thinkers. Let us begin with the materialists.
“Space and time,” says Feuerbach, “are not mere forms of phenomena but essential conditions (Wesensbedingungen)…of being” (Werke, II, 332). Regarding the sensible world we know through sensations as objective reality, Feuerbach naturally also rejects the phenomenalist (as Mach would call his own conception) or the agnostic (as Engels calls it) conception of space and time. Just as things or bodies are not mere phenomena, not complexes of sensations, but objective realities acting on our senses, so space and time are not mere forms of phenomena, but objectively real forms of being. There is nothing in the world but matter in motion, and matter in motion cannot move otherwise than in space and time. Human conceptions of space and time are relative, but these relative conceptions go to compound absolute truth. These relative conceptions, in their development, move towards absolute truth and approach nearer and nearer to it. The mutability of human conceptions of space and time no more refutes the objective reality of space and time than the mutability of scientific knowledge of the structure and forms of matter in motion refutes the objective reality of the external world.
V.I.Lenin, Materialism and Empirio-criticism: Critical Comments on a Reactionary Philosophy, Progress Publishers, Moscow, 1975, 158
Part twenty/to be continued…
Full text at Marxists Internet Archive