Michael Kenny said this quote

The self is constituted within a variety of arenas and in relation to multiple traditions. Self-hood, on this understanding, is both provisional and open-ended, and critically depends on the configuration of relationships between one’s own groups and those cultures and values that are deemed ‘other’. The regulation of alterity becomes a defining attribute of self-hood, as my sense of who I am is crucially mediated by an understanding of that which I am not (paraphrasing William Connolly).