History and future of the concept of "self

The concept of the self has made it possible to think of the organism under the category of identity in order to account for the unity and effectiveness of the system of defense of its integrity. The dualism of self and non-self posits that an organism defends itself by an immune reaction against an external element ("non-self") while sparing the entities recognized as its own ("self"). Phenomena that deviate from this principle (e.g. autoimmune diseases) are classically considered as simple special cases, the general rule being that the self does not trigger an immune reaction against itself. The "self" thus designates the identity core of the body, the substantial entity that allows it to neutralize external threats. However, the scientific status of this organizing scheme based on the self/non-self dichotomy raises a number of epistemological questions about the nature of the self and its location (in the organism itself? In the genes? etc.). The classical model of the self has also been challenged as a metaphysical instance closed in on itself following certain discoveries highlighting the weak permeability of organisms to their external environment. The ontological status of "substance" no longer suits the self since it owes its "being" in part to the exteriority of the non-self.