Conjoined twins: the ambiguity of double effect reasoning.

This essay explores the ethical debate that surrounds last year's case of conjoined ischiopagus tetrapus twins, Mary and Jodie. More precisely, it focuses on those arguments that involved double effect reasoning (DER). A classic model of DER is offered, followed by a summary of the opinions of theologians and philosophers in debating whether such reasoning could be used to justify the surgical separation of these babies. The purpose is to show the "give and take" of ethical discourse, how complex and demanding the application of DER often is, and how elusive finding a "right answer" can be.