This paper enquires into curriculum knowledge about sustainable development at advanced level in geography in English schools through a critical look at two concepts. The deconstructive perspective used is drawn from Jacques Derrida. The focus is on school knowledge and responsibility to other ways of knowing that may be neglected within assumptions concerning the fixed meanings of words, universal laws and the presumptions of scientific method. Michael Bonnett, Martin Heidegger and Iris Murdoch offer transgressive ways of knowing about sustainable development. It is suggested that these ideas might lead to alternative, more ethical and political, and ultimately more objective forms of geographical knowledge.