Re your first statement: no, no we don't. I would respond by saying, with equal unbacked ignorance, yes yes we do.

Re your second, the illustration that the perfectly moral person may have to die in order to achieve the perfect moral state of causing no harm, (which is I think what you're saying). That is only true in YOUR moral principles, which is clearly based on absence of harm. My moral principles are based on much more utilitarian ideas (which, it should be noted, are very very commonly accepted moral principles). Therefore, an outcome (humans being harmed, even if it's yourself), does undermine morality, because the overall utility is lowered by the self harm. Does this make sense? I can explain/illustrate more if that was hazy.