Ought the law feel?

In property, we began discussing property rights in the human body, and had a bit of a debate about whether a person should be able to sell their own body parts. I was one of the few on the side of the right to do so. I should note that I believe there are two restrictions on that right: 1) that no person under 18 should have parts sold (either by their own choice or by that of their parents); and 2) that no person should be able to sell an essential body part while still alive. The first restriction prevents the possibility (horrible though it may be) that impoverished persons would have children solely to "part them out". The second restriction prevents one person giving their life for another. All well-and-good to sell blood, or bone marrow, or a kidney. Not okay to sell your heart or stomach.*

While some of the opponents relied on reasonable (though in my opinion, wrong) arguments as to why we should not be allowed to sell body parts, others did not. The concept that such a system would unfairly punish the poor is reasonable. The concept that it could bring about a black market in human organs is reasonable (though, as I pointed out, there is already a $1 billion-a-year black market in organs harvested illegally). The concept that it would make the recipients feel guilt is not reasonable.

That concept was brought up by a good friend of mine. A family member received a heart transplant some time ago, and as a result, she has deep feelings about the right to sell body parts. She feels that the law should prevent selling organs because the recipients would feel guilt about having the life of one individual sacrificed for another (i.e. the recipient of a heart would know that a person died to give him that heart). Let's forget my second qualifier on the right for the moment (that is, that no living person could donate a heart while still alive).

Should the law deal with emotions, sympathy, or empathy? Does such thinking prevent real legal analysis? I tend to believe that emotions have no place in the law. No matter what case you look at, there is an emotional appeal. Every murderer has a mother. Every house has a history. Even suing a cigarette company could become emotional because you are lower the stock price of retired persons who have savings in safe companies like Altria. But these are irrelevant. They only cloud the true legal questions.

The virtue of the law is that it is neutral, that it relies on logic and reason. It does not waver in the winds of poll data. While the emotions may help to ferret out good reasons in an argument, I am of the opinion that they should not, in and of themselves, be arguments.

I would like to hear other opinions on the matter. Should emotions have a place in the law? If you believe so, how can you get around the problems that such emotions place in the debate?

*I will save the greater debate on property rights in the body for another time. Trust me, I'll be back with data points and everything else you could want in such a discussion. But that is beside the point of this post.