Killing, the victim's interests, and euthanasia

This post is based on the argument of the previous. I am going to argue for the following (material) conditional:

1. If killing an innocent person is wrong because it goes against the victim's interests, then killing an innocent person always goes against the victim's interests.

The Interests Thesis (IT) is that killing an innocent person is wrong because it goes against her interests. The Bad Life Thesis (BLT) is the thesis that it is possible for an innocent person to have such miserable prospects that it is not against her interests to be killed. The conditional (1) can be seen either as providing a reductio of IT or else an argument against BLT. I suspect there are philosophers who accept IT and BLT, for instance accepting IT as a way of countering Marquis-type arguments against abortion and accepting BLT in defense of euthanasia. I think that even if one rejects euthanasia, as I do, BLT has some plausibility (I recall the story about some saint praying for death when very ill—it's wrong to kill the innocent, but perhaps not irrational to pray for death), so overall one might take this argument to provide evidence against IT.

My argument for (1) is very simple:

2. If x is an innocent person who does not consent to being killed, then it is wrong to kill x even if it were in x's best interest to be killed. (Premise)
3. If IT, then it isn't wrong (barring special circumstances such as promises) to kill someone when it is not against her interests to be killed. (Premise)
4. If BLT, then it is possible to have an innocent person such that it is not in her interest to be killed and the "special circumstances" clause in (3) does not apply. (Premise)
5. Therefore, if IT, then not BLT.

There is something tricky in (4), but if one thinks that the special circumstances in (3) involve the existence of additional positive features of the situation that make a killing be wrong (one might say that those are features that make the killing wrong—say, as the breaking of a promise—but don't make the killing murder), I think (4) will be plausible. Could lack of consent be such a special feature? But I don't think it would be a special feature: it would mean that we are gutting IT, and replacing it with the view that what makes killing wrong is that it goes against the person's consent.

Now, the standard justifications of euthanasia involve the claim that euthanasia can be in the interests of the victim/patient. But if BLT is false, then these justifications fail. If there is no other kind of justification, then euthanasia is wrong.

One might try to justify euthanasia by saying that killing someone who validly consents to being killed is not wrong. But this is not a justification of euthanasia as such, but a justification of helping anybody who validly consents to being helped in suicide, whether the suicide is a case of euthanasia or not. I take it to be an essential feature of euthanasia that it be a killing construed to be in the best interests of the innocent victim/patient.

Objection: We need to ask the patient whether she consents to being euthanized because we cannot presume to judge for her whether death is in her interest. Her opinion has a merely epistemic role here.

Response: This confuses consent with opinion, a performative with an assertion. It can be perfectly rational to say: "I know that having A done to me is in my best interest, but I do not consent to having A done to me." And if someone tells us that being killed would be in her best interest but nonetheless does not consent to being killed, it is uncontroversially wrong to kill her. Why would someone think that A is in her best interest but not consent to A? Well, she might think it's immoral to consent to A. Or she might have made a promise to someone never to consent to A, without making any promise to avoid A.