Interdisciplinarity has been a key term in the ecological debate ever since its advent in the early 1960s. The paper addresses these historical links and how the two terms ‘interdisciplinary’ and ‘ecology’ have influenced each other. The later concept ‘sustainable development’ is also truly interdisciplinary, including physical, biological, socio-economic and cultural, as well as normative, mechanisms, contexts and effects operating at scales ranging from the microscopic to the macroscopic. Policies to promote sustainable development need to be based on the type (...) of interdisciplinary thinking that has been advocated for several decades within the ecological debate. This applies not least to research into the sustainability aspects of urban development, the case discussed in this paper. Despite longstanding requests for interdisciplinarity, the development within the academic world has proceeded in the opposite direction. Many of the most influential metatheoretical perspectives virtually prohibit, or at best strongly discourage, the inclusion of insights about certain parts of reality. Here, critical realism could play a very important role as an underlabourer of interdisciplinarity. (shrink)