(This discussion is NOT actually libertarianism, it’s just a conversation about the meaning of saving a life):
If the Titanic is sinking and there’s a choice between two people to rescue, a 10-yr old kid and an 80-yr old senior, and there’s certainly only one more availability in the life boat, which person should get the spot? We all agree the 10-yr old kid should get saved, right? So, we all admit that it’s possible and socially acceptable to, when needed, determine the value of a person’s life and compare it to another. Why do we believe the kid should get saved instead of the senior (assuming there are no other important parameters, just a typical kid and a typical senoir)? Most people agree that it’s because the senior has already had the opportunity to live and enjoy life, but the kid has many years to come.
Next question: If a passerby pushes a kid out of the way of a moving car and saves his life, we all agree that’s a “life saved”. But, what if a 90-yr old senoir is having a heart attack in a lonely alley, and a passerby heroically finds him and takes him to the hospital in time for the senior to get help and stay alive? We would say the passerby “saved his life”. Then, a month later, the senior dies in his sleep of natural causes. After all, he’s really old. Did the passerby really save an entire life in the same sense that the other passerby saved the kid’s life? No, not to the same degree, because he was going to die soon anyway.
Indeed, there’s really no such thing as “saving a life”. Instead, the only meaningful thing, and what we really mean is, that it’s possible to save life time, as in life years. When we saved the kid, we saved many life years because he probably would live another 60 yrs before dying at about 70 (world average life expectancy). If we saved the senior, we only saved a month of life. So, it is meaningless to say “save a life”, but meaningful to say “saving life time”. We can’t save a life, but we can extend a life. Everybody will eventually die. With the Titanic example, we chose to save the kid’s life because we are saving more life years than if saving the senior.
Even though this all sounds very controversial, it is pretty straight forward and obvious. How is this relevant? The main point that I want to make is that it’s only meaningful to speak of extending lives. Even though this is not specifically a libertarian point or idea, it is true, and I will use this when discussing health care for seniors. See this post and this post and this post for a discussion of Medicare.