Sovereignty vs. the Right to Life

The most fundamental and important right a human being has is her right to life. This cannot be justified through first principles because this is itself a first principle. In common sense morality, it is granted that a human being has a fundamental right to life, and that this right trumps all other rights such as the right to liberty and the right to property. It is assumed that you cannot kill your neighbour merely because he’s trying to forcibly take a part of your land for his use. It is assumed that you cannot kill him even if he sleeps on your front yard. If you do not accept this, read no further. I don’t have an argument that could change your mind. There are no universally compelling arguments that could persuade even aliens, computers and rocks. But since you don’t have a right to your life, then I might as well kill you for some utilitarian reason, such as using your biological organs to save more than one life.