What difference does consciousness make?

The question whether and when it is morally appropriate to withdraw life-support from patients diagnosed as being in the persistent vegetative state is one of the most controversial in bioethics. Recent work on the neuroscience of consciousness seems to promise fundamentally to alter the debate, by demonstrating that some entirely unresponsive patients are in fact conscious. In this paper, I argue that though this work is extremely important scientifically, it ought to alter the debate over the moral status of the patients very little. First, the data presented is complex and difficult to interpret; we should be wary of taking the claimed discovery entirely at face value (though the remaining questions will probably be settled by future research). Second, though the demonstration that some of the patients are in fact conscious would show that they are moral patients, and therefore beings whose welfare must be taken into account, it would not, by itself at any rate, show that they have an interest in continued life.