Materialist dialectics is the only scientific epistemology and it is also the only scientific logic. Materialist dialectics studies the emergence and development of our knowledge of the external world, studies how we move from a state of ignorance to one of knowledge and the transformation of incomplete knowledge to more complete knowledge; it studies the increasingly profound and extensive reflection of the principles of development of nature and society in the mind [p. 200] of humankind. This is the unity of materialist dialectics and epistemology. Materialist dialectics studies the most general principles of (p. 279) development of the objective world, and studies the form reflected in thought of the most developed behaviour and characteristics of the objective world. In so doing, materialist dialectics studies the principles of emergence, development, passing away and mutual transformation of each process and phenomenon of material reality; at the same time, it studies the forms in which the principles of development of the objective world are reflected in human thought. This is the unity of materialist dialectics and logic.
To gain a thorough understanding of the reasons why dialectics, logic, and epistemology constitute a single entity, we will turn now to an examination of how materialist dialectics resolves the problem of the mutual relations between the logical and the historical.
Engels said: “In relation to the method of thought of the various philosophers,[2-203] the strong point of the Hegelian method of thought resides in the extremely rich historical sensitivity which permeates its foundations. Although its form is abstract idealist, the development of its thought nevertheless frequently parallels the development of world history. Moreover, history was actually taken as the verification of thought. History frequently progresses through leaps and in a confused manner. Consequently, if history is to be complied with, not only must a mass of insignificant data be given attention, but thought must be allowed to pursue a discontinuous path. At such a moment, the only appropriate method was the logical method. However, this logical method was basically still an historical method, but one which had abandoned its historical form and accidental character”. Marx, Engels, and Lenin paid ample attention to this concept of “the unity of the development of logic and history”. “The categories of Logic are abbreviations for the ‘endless multitude’ of ‘particulars of external existence and of action’”. “Categories constitute divided compartments which help us comprehend the dividing line between classes of things”. “The practical activity of man had to lead his consciousness to the repetition of the various logical figures thousands of millions of times in order that these figures could obtain the significance of axioms”. “Man’s practice, repeating itself a thousand million times, becomes consolidated in man’s consciousness by figures of logic. Precisely (and only) on account of this thousand-million-fold repetition, these figures have the stability [p. 201] of a prejudice, an axiomatic character”.[2-204] These words of Lenin’s demonstrate clearly the distinguishing characteristic of materialist dialectical logic which is dissimilar to formal logic which regards (p. 280) its principles and categories as empty, divorced from content and autonomous, and whose form is unconcerned with content. It is also unlike Hegel, who regarded logic as estranged from the material world, an independently developing conceptual essence, reflected and transplanted in our minds; moreover, he perceived the manifestation of the movement of matter as being dealt with via a process of creation in the mind. Basing himself on the identity of existence and thought, Hegel saw the identity of idealism in the identity of dialectics, logic, and epistemology. In contrast, the identity of dialectics, logic, and epistemology within Marxist philosophy is founded on a materialist basis. Only when materialism is employed to resolve the question of the relationship of existence and thought, and only when one adopts the position of reflection theory, can the problems of dialectics, logic, and epistemology be completely resolved.