Prolonging suffering is unethical

The argument

In cases where terminal illness is incurable and causes a great amount of pain, there's no reason to sustain a patient's life and refuse their wish for an assisted suicide. The two conditions in that sentence do distinct work. That the illness is incurable removes any possibility that the time being preserved is time in which the patient recovers; that it causes great pain establishes what that time consists of instead. Together they leave prolongation without a purpose the patient themselves can recognise. To force someone to remain alive against their will is to force them to live a life they don't want, and that is unacceptable and inhumane. The word "force" is exact here rather than rhetorical. Where the law refuses the request, a patient's own settled judgement about their own life is overridden by someone else's, in the single domain where their authority ought to be least open to question by anyone. If we accept the notion that humanity should strive to limit suffering in its all forms, the denial of the legal euthanasia to terminally ill patients is undeniably cruel. The principle being applied is not unusual or constructed specially for this case — it is the ordinary justification for medicine itself, and for the relief of pain in every other clinical situation. Applying it consistently is what produces the conclusion, and the objection therefore requires treating this one case as an exception to a rule that is otherwise accepted without argument. There is nothing to gain by forcing terminally ill patients to live their lives in agony; thanks to the practice of euthanasia we can put an end to their suffering, which ethically is much more preferable. The balance is one-sided once it is stated plainly: on one side stands suffering that serves no end the patient values, and on the other the relief of that suffering, granted at the patient's own request.

Context

Utilitarianism is an ethical theory positing that the best approach to resolving ethical issues should be the one that seeks to maximize "utility", that is the well-being of sentient agents or at least to minimize their suffering. Voluntary euthanasia is often seen as a resolution to the situation of terminally ill people, whose suffering is often described as senseless and tragic. From a utilitarian perspective, prolonging their suffering is unjustifiable.

Premises

Counter-arguments

The value of human life cannot be made negotiable or dependent on the quality of life. If our main goal is to alleviate suffering, then the palliative care and anesthetics are a preferable alternative since they do not entail moral dilemmas that legalization of euthanasia does and do not compromise a position of a physician as a person whose task is to save lives, not to end them.

Rejecting the premises

[Rejecting P2] There are preferable alternatives to the death of a patient, such as palliative care.