This article reviews the epistemological debates about functionalism in ecology. While identifying current area of scientific validity, t emphasizes, in particular, that functionalism depends on the system examined and remains inapplicable wherever singularity prevails.
The economic agent was previously assumed to be distinct from its environment and that nothing was forcing him to act on it. With the ecological crisis, every agent appears to be inserted into an environment, which he modifies in an irreversible way without even having decided to do so. This changes in depth the way in which economics can represent the agent and the optimal action: it is rationality itself that is modified in what we call « ecological rationality ».
