Rape and Abortion

I apologise sincerely for the brevity of this round. I am attending a wedding soon and have about twenty minutes to finish. In his last round, my opponent raises two objections to my arguments. First, he argues that utilitarianism (a form of which I defend) suffers extreme problems because of the difficulty of demarcation. Second, he claims his attributes for a right to life are not arbitrary. Obviously, I do not accept John Locke's theory of a right to life. Grape argues that having a right to life that can always theoretically be overridden by some other consideration defeats the whole point of a right to life. Why? It's impossible to make precise judgements in such situations. We will never know for sure if we've made the right decision, and will often rely merely on our intuitions. However, I think Grape is overestimating the troubles here. We could still certainly make obvious decisions where, for instance, sacrificing a few lives for the good of many more people would be the right thing to do. In addition, I think Grape's chosen system of simply taking the easy route and claiming the right to life in inviolable and absolute leads to clear absurdities - such as the loss of rights of intelligent animals, mentally disabled and, to take a hypothetical example, aliens with intelligence higher than ours that had evolved very different mental capabilities than us. Grape points out that many countries accept the euthanasia of animals or humans in a vegetative state - this one is easy. Any being in a vegetative state would have virtually no right to life on my system, since it would have virtually no mental faculties relevant to the right to life. I am very unsure of what Grape means by the 'right to be treated well'. If a creature has no right to life, there would be nothing wrong with killing it (or him or her) to cut down on the costs to maintain them. Fine if we should treat them well while they're alive, but we have no obligation to keep them alive. I think Grape is trying to weasel out of the implications of his system a little here. He repeatedly asserts that there is nothing wrong with killing creatures who don't understand their own existence. However, he never really gives an argument as to why this should be the case. Surely, an intelligence creature with social skills that can feel pain and pleasure, and has a moderate level of intelligence still has a right to be alive even if it lacks a complete understanding of its existence? Surely, someone with many of the qualities we understand makes our existence worthwhile but lacks a few essentials ones should have some right to exist? I think this self evident. My opponent points out that I would be unable to pinpoint where the right to life of the child would be overridden by the mother's psychological damage form conceiving a child from rape. Well, as I've already said - I don't have to. I just have to point out that it is a relevant consideration. Obviously making even a reasonable estimate would be difficult - but if we had a fair understanding of how developed a foetus' brain is a different points and what would be lost upon abortion, and weighed it against research of the psychological damage a mother can have on conceiving a child that would be a constant reminder of a terrible act, we could undoubtedly get an estimate of the window where a foetus develops in to something with a serious right to life that would outweigh damage to the mother. Pro argues that his system is not arbitrary because it chooses abilities essential 'by rational conclusion' to the right to life. I find it quite suspicious that these all happen to be abilities that we humans find extremely important. I can think off the top of my head a dozen mental capabilities we are unable to perform which would be highly relevant to a right to life, but which Grape would dismiss as peripheral. I'm afraid I have to go. Thanks to Grape for a great debate!