  The term “ecosystem” was coined in 1935 by Tansley who defined it as “the whole system (in the sense of physics) including not only the organism-complex [that is, the community], but also the whole complex of physical factors forming what we call the environment of the biome—the habitat factors in the widest  sense.”[75]  Tansley went on to argue that ecosystems “are the basic units of nature on the face of the earth.” For Tansley, using the term “ecosystem” implied a physical description of a community in its habitat. Even though that perspective still illuminates ecosystem studies (see below), it is no longer a necessary or even common connotation of the term “ecosystem.” However, independent of the use of “ecosystem,” ecosystem ecology, in contrast to other ecological sub-disciplines, and in continuity with its history, does retain an emphasis on physical processes. Should ecosystem ecology, then, be regarded as an instance of the unification of the physical and biological sciences? There has been so little philosophical attention to ecology that this question does not appear ever to have been broached.