In a paper delivered to the Aristotelian Society on 12 March 1956, Walter Bryce Gallie introduced the term essentially contested concept to facilitate an understanding of the different applications or interpretations of the sorts of abstract, qualitative, and evaluative notions—such as "art", "philanthropy", "power" and "social justice"—used in the domains of aesthetics, sustainable development, political philosophy, philosophy of history, and philosophy of religion. Wikipedia