Definitions of sustainability—and criticisms of the definitions—abound. I argue that there are problems with the definitional approach itself and not just with any specific definition. Wittgenstein. Macmillan Publishing Company, New York, 1958) argued that definitions are not sufficient to determine meaning or to legislate correct usage of words. For both singular terms and general concepts, meaning is meaning-as-use, proceeding via examples that instruct within an already existing normative structure. Once we are clear on the ways in which use presupposes a (...) normative structure, I believe we will understand better the meaning of sustainability and its normative basis. On this view, sustainability will be vague and contested but not meaningless. And we will not have to be worried about the plethora of definitions. (shrink)