Is the Self Indefinable?

Post modernism is actually very much in line with supy metaphysics, at least on this when it cas doing away with the idea of kind of fixed essence. We no longer think about these ethical barriers that might actually prevent having tprevent you from having proper, true self knowledge. This is very antithetical to the islamic and i should venture to say, also greek and even indian ideas of the sell. Cogito exisom, i think, therefore i am.