In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However, this limit is theoretically indefinite. There is thus an area of inclusive practice that is not theoretically justified, and we are not able to explain the limit to inclusion in the pedagogical practice theoretically. Instead, it is explained as individual difficulties, the teacher's lack of containing diversity or the need of developing new forms of interventions. That is all conditions which are outside the scope. This article provides a way to explain the limit to inclusion theoretically in the conceptual identification of inclusion by establishing that exclusion processes are an internal part of inclusion processes and that we cannot investigate inclusion without investigating exclusion.