i agree the value we put on people is subjective. but i don't think it's arbitrary (not that you were saying it was) to place value on people. the average human places positive value on other human beings because our species evolved by working together as a group. and even though today we like to think of ourselves as independent, we are largely reliant on the rest of our society to do the vast majority of tasks we take for granted. if i didn't live in a society, i'd be off hunting my dinner right now, not rambling on a forum on my computer. that being said, the question still remains whether or not placing value on human life actually is a productive way to prevent harm to human life. in my opinion, a general sense of empathy
would be productive, where as simply having a high value for those close to you
would not necessarily.
Do I value humans more than the entire Earth? Absolutely
i think i'd go with the earth. just from a gut reaction, if you told me i had to chose between being the last human on earth, or flying away from an exploding earth on a spaceship with x amount of human beings, i'd go with the earth. but that's me.