The task, bequeathed to us by Lenin, of creating a Logic (with a capital 'L'), i.e. of a systematically developed exposition of dialectics understood as the logic and theory of knowledge of modern materialism, has become particularly acute today. The clearly marked dialectical character of the problems arising in every sphere of social life and scientific knowledge is making it more and more clear that only Marxist-Leninist dialectics has the capacity to be the method of scientific understanding and practical activity, and of actively helping scientists in their theoretical comprehension of experimental and factual data and in solving the problems they meet in the course of research.