Analyzing the historical forms of moral solidarity, one of which is the phenomenon of fraternity and trying to see in this form the foundations of constructive cooperation in modern conditions, we should pay close attention to the underestimated conceptual provisions and mechanisms. We believe that these factors play an important role in overcoming disintegration processes, both at the level of social communication and at the level of the mental foundations of intercultural and intercivilizational communication. The article is devoted to the philosophical foundations of the phenomenon of fraternity, mainly based on the material of European and domestic socio-philosophical reflection. The relevance of this topic is determined by the fact that the current international situation presents new challenges and that Russia is looking for constructive solutions to complex contradictions that have arisen in the international community. On the other hand, the axiological foundations of Russian civilization, which have been its genetic basis for many centuries, require constant philosophical reflection. The article discusses the essential importance of the phenomenon of fraternity for overcoming social disharmony, clarifies the advantages of this form of social interaction over formal cooperation. The methodology of the work is based on a socio-philosophical analysis of the axiological and ethical foundations of various forms of joint human activity. The article attempts to identify the structure-forming foundations of the system of social relations by the example of the phenomenon of fraternity.