 Once again, however, there is no reason at all why physicalists need to accept that reductionism is true in the sense of (10). We noted earlier that the possibility of multiple realization renders type physicalism implausible; something similar is true in this case. Many different neurobiological processes (whether in our own species or a different one) could underlie the same psychological process — indeed, given science fiction, even non-neurobiological processes might underlie the same psychological process. If so, (10) seems to be false. (For a classic presentation of multiple realization and reductionism, see Fodor 1974, but for an alternative view, see Kim 1993).