Special education development internationally is lifting up several issues for better understanding the roots of inclusive education as a theory and a practice. Ratification and acceptance of international documents in different aspects of disability, forces countries to pay attention to national particularities for further implementation of inclusion in education. National special education systems have their unique socio-cultural patterns, developed out of research ideas and societal traditions. To understand inclusive education as a theory and a practice means to understand the socio-cultural nature of special education and the role of it as ‘a cultural mediator’ between children with disabilities and society. Formation of the soviet system of special education was reinforced by an extreme ideological belief in pedagogical methods of forming/correcting/re-upbringing future citizens, ideas of which were embedded in the fundamentals of defectology as an integrative science. Officially, defectology was never recognized as a science among social and humanitarian sciences in the national classifier of sciences, but played one of the key roles, studying ‘child disability’ and ‘special education’ for them. Presentation will be focused on some issues of ‘child disability’ and special education, which were central for soviet defectology, interpreting them by the history of ideas methodology