Has science ever been normal? On the need and impossibility of a sustainability science

In this article, I develop a constructive critique of 'post-normal science' by challenging the underlying conception of 'normal science'. Invoking Bruno Latour's constructivist approach, I change focus from a representationalist understanding to a practice-inspired account of science in which the composition of a matter of fact necessarily implies a politically significant differentiation between internalities and externalities. Contending that science has never been normal in that it has always already been political, I further elaborate on this political dimension by connecting Latour's concepts of matters of fact and matters of concern with Rudolf Boehm's distinction between logical and topical truth. Whereas logical truth is a measure of the validity of matters of fact, topical truth is a measure of the relevance and adequacy of scientific knowledge regarding a particular matter of concern. This allows me to argue that any attempt to install a new 'post-normal science' with a higher topical truth visa-vis sustainability issues neglects the irreducible political moment situated at the point of determining who and what we should be concerned about. Finally, I draw on the notion of 'forms of life' to suggest a 'politics of the imaginable' that takes socio-material practices as primary matters of a concern for sustainability. (C) 2011 Elsevier Ltd. All rights reserved