Acts and omissions: killing and letting die.

It is widely assumed in medicine that a doctor must never kill his patient but he may be morally permitted or indeed morally required in certain circumstances to let the patient die (1). The distinction is sometimes seen as a sub-species of a broader distinction which holds that while it may be morally impermissible actively to do something with certain bad results it may none the less be morally permissible to let something happen which has the same bad result. The distinction is sometimes referred to as the 'acts and omissions doctrine' and it seems to be enshrined in medical ethics folklore in A H Clough's satirical line 'thou shalt not kill but need'st not strive officiously to keep alive' (2). It is widely used by doctors to justify withholding life-saving treatment in circumstances in which they would condemn killing a patient but in which they believe the patient's death from natural causes would be morally acceptable. Thus in cases of terminal disease, for instance, life-saving antibiotics or livesaving resuscitation measures are often withheld; and in cases where newborn infants have severe defects such as spina bifida or Down's syndrome, active medical treatment for life-threatening conditions is sometimes withheld. In both types of case, however, active killing would generally be considered morally unacceptable by the doctors concerned. A similar distinction is recognised in English law, which does not permit doctors to kill their patients but does permit them to withhold life-saving treatments in certain circumstances and to administer pain-relieving treatment even in the knowledge that to do so is likely to shorten the patient's life (3). Philosophers have repeatedly attacked the moral validity of the acts-omission doctrine, especially in the context of killing and letting die. Rachels, for example, in a controversial paper in the New EnglandJournal of Medicine argued that there was no moral importance in the distinction, that in the context of making life-anddeath decisions it was morally irrelevant, that it could lead to 'patently cruel' results, and finally that the common arguments in support of the moral relevance of the distinction were invalid (4). Rachels is but one of a host of philosophers who have argued against basing life-and-death, moral decisions solely on the distinction between whether a person actively does something which results in another's death or omits to do something, the omission resulting in another's death (5). Rachels illustrates his moral-irrelevance argument by considering a Down's syndrome baby with duodenal atresia and one without, but otherwise in similar circumstances. Sometimes parents withhold permission for operation on the duodenal obstruction and the infant dies. The reason for withholding the operation is that the child has Down's syndrome 'and the parents and the doctor judge that because of that fact it is better for the child to die'. On the other hand if the child does not have the duodenal obstruction the child lives on even if the parents and doctors think that it would be better if the child were to die. Rachels calls the situation 'absurd'. If the life of such an infant is worth preserving when it does not have duodenal obstruction then it is worth preserving when it does have duodenal obstruction; conversely if it is judged better that the Down's syndrome infant with duodenal obstruction should die then the same judgement should be made about the unobstructed Down's syndrome infant;'what difference does it make that it happens to have an unobstructed intestinal tract? In either case the matter of life and death is being decided on irrelevant grounds'. Rachels supports his argument that the distinction is not in itself of moral importance by postulating two cases exactly alike except in the fact that one involves a killing and the other a letting die. Thus Smith, standing to gain a fortune from the death of his sixyear-old cousin, surreptitiously drowns the boy in the bath, and makes it look like an accident. Jones who also stands to gain a fortune from the death of his cousin sneaks into the bathroom intent to drown the boy but sees the child slip, bang his head, fall unconscious and drown. Jones waits to make sure he dies, ready to push the boy under ifhe wakes, but he drowns accidentally. Clearly, argues Rachels, the only difference built into the examples is that in one a man killed his six-year-old cousin and in the other he 'merely' let his cousin die. In the absence of further distinctions between the two cases there is no plausible basis for finding Jones less morally culpable than Smith or for finding any moral distinction between the case of killing and the case of letting die. Therefore the difference between killing and letting die can not be, in itself, ofmoral relevance. coright.