In his recent NDPR review of Rupert's Cognitive Systems and the Extended Mind, Wilson rejects the search for a "mark of the cognitive" roughly on the grounds that it is a bit of conceptual analysis, hence that the search a dubious enterprise. (Wilson's text below the fold.)
But, when Rupert cites such things as the "generation effect" in order to argue that Otto's notebook does not constitute memory, it does not look like Rupert is doing conceptual analysis. That normal human memory displays a generation effect is an empirical discovery.
Thus, we need a principle of demarcation that delineates mere causes from genuine constituents of cognition.
There are two short but basic questions to pose here. First: why? Second, one that I have picked up at occasional postmodernist seances: who are “we”? Take them in reverse order. Precisely who needs this kind of principle of demarcation? Surely not practicing cognitive scientists, in part because they seem to have gotten along perfectly well without one until now. Philosophers? Well, not philosophers who take one of the chief lessons of the failure of logical positivism in the philosophy of science, the collapse of the analytic-synthetic distinction along Quinean lines in the same, and the limitations of conceptual analysis to be a deep suspicion of the search for such principles.