The evolution of society cannot be regarded as an instantaneous replacement of one system by another in all the countries of the world. By virtue of the fact that in each country the internal and external conditions of development are different, the transition from one socioeconomic system to another is not accomplished at one and the same time on a world-wide scale. Thus, at any given stage of its development, society, as a whole, represents a complex picture of different but interlacing socioeconomic systems and ways of life, of classes, social groups, nations and states acting on each other and often engaged in bitter struggle with each other. Take contemporary mankind. One-third of it is building socialism and communism, while the remaining two-thirds live in non-socialist countries. Among the latter are countries with developed 55 capitalism and imperialism, countries at pre-capitalist stages of development, and so forth. Moreover, millions of people, chiefly Africans, continue to languish under the colonial yoke. This state of society as a whole at a definite stage of development is expressed by the concept epoch. This concept covers a diversity of phenomena of human history and it stresses, mainly, that which is basic, general and typical in this diversity. Lenin required that we should distinguish the “typical” and the “different” in each epoch. He constantly analysed this “typical”. To find what is typical, objectively basic in historical phenomena, i.e., to determine the predominant trend of social development at a given stage, to show which class champions this trend is a major requirement for defining a concrete epoch. “We cannot know,” Lenin wrote, “how rapidly and how successfully the various historical movements in a given epoch will develop, but we can and do know which class stands at the hub of one epoch or another, determining its main content, the main direction of its development, the main characteristics of the historical situation in that epoch. ...” In order to elucidate the nature of a given epoch we must, first and foremost, determine in what direction mankind is moving and which class personifies this movement.