I shall argue that there is no theoretically respectable reason for separating the mind off from the world in the way the internalist picture tells us we should. There is, in other words, no theoretically respectable reason for thinking of cognitive processes as purely and exclusively internal items. And to say there is no theoretically respectable reason, here, simply means that there is no reason that can be derived from psychological theory as such. The parsing of the realm of cognition into, on the one hand, cognitive processes that are conceived of as purely internal items and, on the other, external causes, stimuli, orcues of these internal items is not something that is demanded by our theorizing about the mind, but an optional extra. It is a pre-theoretical picture we use to interpret our explicit theorizing, not something mandated by that theorizing. It is, in short, a mythology.
(Rowlands, 1992, pp. 12-13)
Rowlands, M. (1999). The Body in Mind. Cambridge: Cambridge University Press.