"If it saves just one life, it's worth it."

A few years ago, the town I live in built a stoplight at an intersection where a high school girl had died in a car accident. While they were building it, I drove past there with a friend of mine and his mother. When he commented that there was really no need to build a street light there, his mother said, "If it saves just one life, it's worth it."

Now, it's possible that his mother knew how much it cost to build and maintain a streetlight there, and decided one life would be worth it, but it's far more likely that she meant that any expense is justified if it saves "just one life"; i.e., lives have an infinite value. This, of course, is absurd, because it would imply we should devote all of our resources towards saving lives. This, in turn, becomes even more absurd, because there are various places towards which resources must be directed to save lives (food, shelter, healthcare, etc.), but if lives have an infinite value, it becomes impossible to efficiently determine just how these resources should be allocated towards saving lives. Infinite values do not work well in a market.

In short, it's clear that lives do not have an infinite value, and there must be some finite value we could place on a life. There must be some dollar value that it's not worth spending, even "if it saves just one life". However, as a society we're extremely uncomfortable placing a finite value on a life, and try to treat all lives as having infinite value, even though this is an untenable position. It is, I think, not difficult to see how many political disagreements can and do stem from this dilemma.