I am painfully aware that as Robin points out many great minds have debated these issues since at least the time of the ancient Greeks. Nevertheless this is a blog, not an academic journal, and we won't have much of a conversation if we all remain silent except when we can add to the insights of the greats.

I want to point out that even strong moral rules like the one against killing have exceptions. Most people believe that killing is right in some circumstances. Many people support the death penalty for murderers, for example. Another case is the doctrine of "just war", where killing enemy soldiers may be seen as part of a greater good. At somewhat the other side of the political spectrum, many would support killing someone who was on life support and had previously expressed a desire not to be kept alive in that state.