Saying that human life is valuable is an entirely subjective, and perhaps even biased point of view, considering that humans are the only ones who think this is the case. I don't know whether I agree or not that it's valuable. A lot of it depends on individual beliefs I suppose. My opinion is that once we're dead, all we do is rot in ground. I do agree that if we lose a human being then the things that human being would have done are lost also, BUT who the hell knows what those things would have been. He/she could have become a serial killer or something. So, I don't think that society is always worse off having lost someone. That said, on this particular forum, there are a lot of good people who don't think that their existence is worthwhile because they're sick, and that's usually not the case.