In the article, using the methodology of system analysis, system-functional, system-structural and system-component aspects of the system approach, as well as the method of expert assessments of authoritative specialists professing a realistic approach to understanding and cognition of truth, materialistic dialectics is considered as a composite This part of the realistic theory of knowledge, the epistemological basis of a realistic approach to understanding and knowing the truth in various spheres of cognition, including in criminal proceedings. It is substantiated that one of the reasons for the unproductiveness of the endless discussion between supporters and opponents of the concept of objective truth in the Russian criminal process is that some modern participants in this discussion from both sides in their understanding of dialectical materialism as the epistemological basis of the realistic approach to understanding and knowing the truth stopped at the level of Soviet official philosophy, not taking into account that dialectical materialism is productively developing through philosophical comprehension within the framework of complex and systematic approaches of the achievements of various branches of the natural sciences and humanities covered by the concept of “cognitive sciences”, which contributes to a deeper understanding of the foundations, system-forming factors of the realistic approach to understanding and cognition of truth.