When applied to ecological objects, instrumental rationality naturally takes the form of functionalism: the question is then to know what is the ‘function’ of these objects (i. e. organisms, species, communities, etc.) in the system that contains them. Faced with a systemic issue like the ecological crisis, such an approach is particularly useful, as it allows to represent a complex or intertwined reality and solve it rationally, by assuming functional equivalences between the system’s elements. While functionalism has grown in popularity since the emergence of environmental issues in the 1970s, however, the concept has only a narrow range of scientific validity. This article reviews the epistemological status of functionalism in ecology and highlights some important implications for ecological economics. One of the most important aspects is that there is no such thing as « functioning » in nature: functionalism is a view of the mind, which depends directly on the field or the object studied. It follows that functionalism can never be separated from a specific ecological structure, and that it becomes inapplicable wherever singularity prevails. Since singularity is omnipresent in ecology, the application of a functionalist perspective appears particularly delicate. While instrumental rationality stays relevant and necessary, in our opinion, to respond to the ecological crisis, we contend that economists (as well as all theorists who opt for an instrumental perspective) risk conceptualizing the environment through purely abstract functionalism, i. e. of supposing functional equivalences that do not correspond to any ecological reality. Following Horkheimer and Adorno, we argue that such reasoning brings about the “fetishism of equivalence”, of which functionalist thinking could be a contemporary variation.
