Deal with the real, not the notional patient, and don't ignore important uncertainties.

There is a strong presumption in favour of the maintenance of life. Given sufficient evidence, it can be rebutted. But the epistemic uncertainties about the best interests of patients in prolonged disorders of consciousness ('PDOC') and the wishes that they should be presumed to have are such that, in most PDOC cases, the presumption cannot be rebutted. It is conventional and wrong (or at least unsupported by the evidence) to assume that PDOC patients have no interest in continued existence. Treatment withdrawal/continuation decisions should focus on the patient as he or she actually is, and should not unjustifiably assume that the premorbid patient continues to exist unchanged, and that the actual patient has the same interests as the premorbid patient and would make the same decisions in relation to treatment as the premorbid patient would have done.