When philosophofofosizing about morality or ethics, people often bring up rather horrible situations in order to create a relevant thought experiment. So forgive me - I'll make it really broad.
If we had to make a terrible choice between allowing a 30 year old to live and allowing a four year old to live, assuming there were no practical considerations concerning physical ability and subsequent chances of survival or anything, I think most of us would choose to preserve the four year old.
We have an instinct to protect the younger person to a greater degree than the older person. Perhaps we feel it is because of her "innocence" - her lesser degree of understanding (perhaps?) of the situation at hand. Since I am trying to dig into this a bit - I am guessing much of this instinct to protect comes from our desire to preserve more of life. The four year old has a greater potential for more life ahead of her. The 30 year old has more of her life in the past. The thirty year old has already lived.
If we had to choose between saving a four year old and a four week old, what would we choose? This is much more difficult. I think that perhaps we would choose the four year old.
This would be because the four year is more aware, having more thoughts, feelings and experiences.
So perhaps we greatly value the potential for life, yet we also consider who or what is holding this potential when making value judgements. I suppose this is a balance of values - the potential for future thoughts, feelings and experiences weighed alongside the holder of that potential's current ability to have thoughts, feelings and experiences. The potential for life is weighed alongside the current level of ability to experience life in a meaningful way.
Do you agree with my ethical intuitions? Would you make the same choice?
Once again, this is really unpleasant to consider, I apologize. Obviously weighing values and being forced to make a decision does NOT mean that there is not a tremendous amount of value on both sides of the scale. I just find it really relevant to ponder this stuff sometimes.