Conceptual aspects of social unity and their interrelations are discussed. Semantic analysis of concepts depicting social unity is offered. Author distinguishes two types of social integration designated as “integration of society” and “integration with society”; or “integration in society”; in latter case its meaning is closely related to those of “adaptation”, Contents. Summaries 171 “socialization”, and “inclusion”. Besides, two other aspects of social integration, namely social cohesion (solidarity, consensus), on the one hand, and social regulation (rules, norms and values), on the other hand, as well as the interaction between them, are analyzed. Crucial role of “abstract rules” in the 21st century large societies, including Russian one, is emphasized. According to author, two forms of social integration – cohesion and adherence to abstract rules – are fused in civil solidarity and civil society.