I was having a discussion with someone, and she said she could never trade a life for lives.
An example is:
Armed people take over a crowded school. They want someone to come in so they can kill him/her for reasons of their own. If that person doesn't arrive to meet his/her death in a hour, they will kill the students of the school.
What kind of person are you? Would you send the man/woman to his/her death to save the kids, or would you refuse and find another way that is most likely to end in several school deaths and the deaths of the hostage keepers?
I, personally, would ask the man/woman if they were willing to die to save the school children. If he/she was, I would let him/her. I would never force that person though. If they didn't want to go, I'd find another way.