Theoretical Medicine and Bioethics

, Volume 31, Issue 4, pp 285–301 | Cite as

Animalism and the varieties of conjoined twinning

  • Tim Campbell
  • Jeff McMahan


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.


Animalism Personal identity Dicephalus Craniopagus parasiticus Cephalopagus Too-many-subjects problem 



We are grateful to Jacob Ross and Dean Zimmerman for comments on an earlier draft of this paper.


  1. 1.
    McMahan, Jeff. 2002. The ethics of killing: Problems at the margins of life. New York: Oxford University Press.Google Scholar
  2. 2.
    McMahan, Jeff. 1998. Brain death, cortical death, and persistent vegetative state. In A companion to bioethics, ed. Helga Kuhse and Peter Singer, 250–260. Oxford: Blackwell.Google Scholar
  3. 3.
    Miller, Kenneth. 1996. Together forever. Life April: 44–56.Google Scholar
  4. 4.
    Olson, Eric. 2007. What are we?. New York: Oxford University Press.CrossRefGoogle Scholar
  5. 5.
    Olson, Eric. 2004. Animalism and the corpse problem. Australasian Journal of Philosophy 82: 265–274.CrossRefGoogle Scholar
  6. 6.
    Olson, Eric. 2008. Replies. Special issue I. Abstracta 4: 32–42.Google Scholar
  7. 7.
    Shoemaker, Sydney. 1999. Self, body and coincidence. Proceedings of the Aristotelian Society 73: 287–306.CrossRefGoogle Scholar
  8. 8.
    Shoemaker, Sydney. 2008. Persons, animals and identity. Synthese 162: 313–324.CrossRefGoogle Scholar
  9. 9.
    Noonan, Harold. 1998. Animalism vs. Lockeanism: A current controversy. The Philosophical Quarterly 48: 302–318.CrossRefGoogle Scholar
  10. 10.
    Baker, Lynne. 2007. The metaphysics of everyday life. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  11. 11.
    Hershenov, David. 2005. Persons as proper parts of organisms. Theoria 71: 29–37.Google Scholar
  12. 12.
    Liao, S. Matthew. 2006. The organism view defended. The Monist 89: 334–350.Google Scholar
  13. 13.
    George, Robert, and Patrick Lee. 2008. Body-self dualism in contemporary ethics and politics. Cambridge: Cambridge University Press.Google Scholar
  14. 14.
    Reid, Mark. Forthcoming. A case in which two persons are one animal. In Essays on animalism, ed. Stephan Blatti and Paul Snowdon. Oxford: Oxford University Press.Google Scholar
  15. 15.
    McMahan, Jeff. 2009. Death, brain death, and persistent vegetative state. In A companion to bioethics, 2nd ed, ed. Helga Kuhse and Peter Singer, 286–298. Malden, MA: Wiley-Blackwell.Google Scholar
  16. 16.
    van Inwagen, Peter. 1990. Material beings. Ithaca: Cornell University Press.Google Scholar
  17. 17.
    Olson, Eric. 1997. The human animal: Personal identity without psychology. New York: Oxford University Press.Google Scholar
  18. 18.
    Hudson, Hud. 2001. A materialist metaphysics of the human person. Ithaca: Cornell University Press.Google Scholar
  19. 19.
    Shewmon, Alan. 1998. ‘Brain-stem death’, ‘brain death’ and death: A critical re-evaluation of the purported equivalence. Issues in Law and Medicine 14: 125–145.Google Scholar
  20. 20.
    Hovorakova, M., R. Peterkova, Z. Likovsky, and M. Peterka. 2008. A case of conjoined twin’s Cephalothoracopagus Janiceps Disymmetros. Reproductive Toxicology 26: 178–182.CrossRefGoogle Scholar
  21. 21.
    Kokcu, Arif, Mehmet B. Cetinkaya, Oguz Aydin, and Migraci Tosun. 2007. Conjoined twins: Historical perspective and report of a case. The Journal of Maternal-Fetal and Neonatal Medicine 20: 349–356.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  1. 1.Department of PhilosophyRutgers UniversityNew BrunswickUSA

Personalised recommendations