We defend the view that we are not identical to organisms against the objection that it implies that there are two subjects of every conscious state one experiences: oneself and one’s organism. We then criticize animalism —the view that each of us is identical to a human organism—by showing that it has unacceptable implications for a range of actual and hypothetical cases of conjoined twinning : dicephalus, craniopagus parasiticus, and cephalopagus.

In dicephalus conjoined twinning, it appears that two heads share a body; in cephalopagus, it appears that two bodies share a head. How many human animals are present in these cases? One answer is that there are two in both cases—conjoined twins are precisely that, conjoined twins. Another is that the number of humans corresponds to the number of bodies—so there is one in dicephalus and two in cephalopagus. I show that both of these answers are incorrect. Prominent (...) accounts of biological individuation, which treat the organism as an integrated whole, reveal that in these and other cases of conjoined twinning the ‘twins’ share a single human animal. This has a number of consequences for the debate about what we are. First, if animalism is true, individuals of our kind can be—and are—profoundly psychologically divided. Second, cephalopagus twinning does not divide animalism from its rivals, as has been claimed. Finally, animalists can reply to a vicious species of the ‘too many thinkers’ problem to which they are allegedly uniquely vulnerable. (shrink)

Animalism is the doctrine that you and I are animals. Like any substantive philosophical position, animalism faces objections. For example, imagine a case of conjoined twins, where there are two heads, but only one “body,” and where each head seems to have its own typically human and fully discrete mental life. It would be natural to assume that each of the twins is a thing like you and me—each twin is one of us. But it appears that each twin cannot (...) be a distinct human animal, since it appears in this case that there is only one animal. So it appears that animalism renders the wrong verdict in this case. I present two responses to this worry, drawing on Aristotelian claims about the centrality of sensation to animals, and on an account of organism-hood from Maureen and Samuel Condic. I close by considering craniopagus parasiticus and cephalopagus, and show the Aristotelian response is effective in such cases as well. (shrink)