I think that the lifespan that humans can live to if they wish, given current medical and scientific knowledge, is too low.
I agree.
The model I use to derive that involves looking at lots of dying people who don't want to die. If we had lots of people lying around saying "I wish I could die; why can't I die?" that same model would conclude the lifespan is too long.
Another month, another rationality quotes thread. The rules are: