I am having a discussion on reddit (I am TheMeiguoren), and I have a a moral quandry that I want to run by the community.

I'll highlight the main point (the context is a discussion about immortality):

imbecile: For someone to have several lifetimes to be considered a good thing, it must be conclusively shown that this person improves the life of others more and faster than several other people could achieve in their lifetime together with the resources he has at his disposal.

me: If my existence really was harming the human race by not being as efficient as possible, I believe I would fight, well, to the death to preserve my existence. However, I would not do this at the expense of harming humanity. I notice that my goals are contradictory, I'm going to have to reflect on this.

My current moral heuristic is utilitarian tuned by degrees from self. (I.e. self > family > friends > other humans > sentient animals > other life > inanimate matter, other intelligent life fits somewhere in there). imbecile considers this animalistic and archaic, I see it as the value system that best fits my ontology, and choosing a moral system is largely arbitrary, anyway. In the current world, I believe I would sacrifice myself for the lives of my (hypothetical) children. But if I am able to live forever, I am torn as to whether this is the right action, assuming my existence used up valuable resources that harmed humanity's offspring.

So two questions:

• Is my degrees-from-self moral heuristic a valid one? I at least find it to be internally consistent. Or to put it another way, just how arbitrary is one's moral system?

• Within the frame of this moral system, in a post-humanity situation where my very existence hurts the rest of humanity by using resources less efficiently than possible, is sacrifice the best course of action?