To this day, general pedagogy has largely excluded the issues of disability, leaving them to special education. Special education has often objectified disability as a natural trait or fate, declaring it a subject for special treatment that is deemed most appropriate for addressing this issue. The modern debate on integration or inclusion has not completely overcome this division. In reality, however, disability is always a social construction, as Jantzen elaborates. The social isolation associated with disability affects psychological development just as much as it does its biological foundations. Wolfgang Jantzen's textbook, now a classic not only in the field but also in the humanities as a whole, breaks with such positions. It connects to the cultural-historical theory and activity theory of Vygotsky and Leontiev.