It is not easy to state what disability is. In order to answer to this question referring to the twentieth century – except for some prominent personalities in the scientific context (Binet, Decroly, Montessori, Vygotskij) – it could be stated that the second half of the century marks the end of a millenary era in which the topic of disability was viewed merely in fatalistic terms. During the second part of the century, there were attempts to delineate the concept of disability through different conceptual and interpretative models, all of them being very interesting from a scientific point of view (Disability Studies, Disability Creation Process, OMS' Classifications, Capability Approach).

The reflection about human experience reveals a certain divergence between the condition of the individual, centred in their own biographic reality, and the effects of the social construction that determine different life conditions, which result to be standardised by concepts and categories. Depending on the incisiveness of such effects, the understanding and peruse of the disabled person's existential condition become involved.

In facts, if we consider the classificatory models singularly, they do not seem to be sufficient to show and to describe the sense and the meaning that disability has in relationship to the peculiarity of existential life conditions. Combining them into a single one is not enough. Our analysis argues and shows in what sense they don't completely satisfy the perspective into which the Italian Special Pedagogy conceives disability and inclusive processes at school, especially from the point of view of teachers' didactical work.

The way in which each individual conceives themselves and understands their own condition plays a determinant role in the definition of their health and life conditions, but this is a question that does not find a full answer in any of the interpretative models of disability. In order to be understood in the most authentic way, disability has to be conceived as an existential condition that needs to take into account the identity of the disabled person referring to their personal real life dimension, rather than to the interpretative models only.