What is the extension of the extended mind?

Two aspects of cognitive coupling, as brought forward in the Extended Mind Hypothesis, are discussed in this paper: (1) how shall the functional coupling between the organism and some entity in his environment be spelled out in detail? (2) What are the paradigmatic external entities to enter into that coupling? These two related questions are best answered in the light of an aetiological variety of functionalist argument that adds historical depth to the "active externalism" promoted by Clark and Chalmers and helps to counter some of the core criticisms levelled against this view. Under additional reference to conceptual parallels between the Extended Mind Hypothesis and a set of heterodox theories in biology-environmental constructivism, niche construction, developmental systems theory-an argument for the grounding of environmentally extended cognitive traits in evolved biological functions is developed. In a spirit that seeks to integrate extended functionalism with views from cognitive integration and complementarity, it is argued (ad 1) that instances of environmental coupling should be understood as being constitutive to cognitive functions in either of two distinct ways. It is further argued (ad 2) that the historically and systematically prior environmental counterparts in that coupling are features of the natural environment. Language and linguistically imbued artefacts are likely to have descended from more basic relations that have an extension over the environment.