 Multiple realizability might well begin at home. For all we now know (and I emphasize that we really do not now know), the intentional mental states we attribute to one another might turn out to be radically multiply realizable at the neurobiological level of description, even in humans; indeed, even in individual humans; indeed, even in an individual human given the structure of his central nervous system at a single moment of his life. (1993: 308; author’s emphases)