The short answer: Your royal We (“We know what it means”) refers to economists. I am doing moral philosophy. The end!

The longer and related answer: Here’s where I think moral philosophy has some different work to do than economics. Interestingly, in the health care arena, people often use the language of pricelessness. For example, when confronted with the fact that universal health care might reduce access to wildly expensive but marginally efficacious treatments, some say: “but you can’t put a price on life.” Or, I’m sure that some people would have the following reaction to the analysis of euthanasia under which valuing your life means that “I am willing to pay more for you to live than you are willing to pay to die”: “but no amount of money could ever make my life worth living!” I think this language is very curious indeed, and I don’t quite know how to make sense of it. Yet, on the other hand, I am uncomfortable with explanations of moral phenomena that explain away what appear to be prominent features of moral thought, behavior, or speech. The economic analysis possibly does so.

The way to avoid all of this is to press on the fact that valuing someone else’s life is really just a way of talking about your preferences regarding what they do, willingness to pay to secure them notwithstanding. Liberal political philosophy can deal easily with such preferences — they are generally not state enforceable. This move is available from the philosophical perspective, if not the purely economic one.

What do you mean by “What could it even mean to say that ‘I value your life more than you do’?”? We know what it means: that I am willing to pay more for you to live than you are willing to pay to die. In principle we could trade—I would pay you enough money to make your life worth living again. However, there are serious transaction costs which prevent the exchange from happening. The market breaks down due to moral hazard (say, attempts at parental extortion), among other things. The state’s interest in prohibiting euthanasia is merely to restore the outcome which would have occurred if the market functioned properly. Yes, it is coercive in a narrow sense, but only in the same way that laws against littering in a commons are coercive.

You’re not a litterer, are you?