[robbedpeter]

Every argument for death strikes me as silly. If anything, functional immortality would incentivize people to be better. Your want relationships to be stable and mutually respectful at a minimum. Marriages would be somewhat hard to maintain - if you were in good health, mid 20s body, and expected to live centuries in that state, lifelong commitments achieve that "quantity is sometimes a quality all its own" effect.

We'll need a different scale of maturity, too - an 18 year old adult in a relationship with a 300 year old adult makes the term "adult" ridiculously ineffective in describing anything meaningful.

Age and death and maturity tie in to almost every aspect of life and culture and human experience. We don't have the cultural tools and concepts that allow for immortality to fit. If it's achieved, the world radically changes and we won't know what those changes will be until it happens. It'd be like tasking Edison with predicting how the internet would change life, or cell phones, or asking Julius Caesar to write about how the germ theory of disease might improve the human condition. We're smart enough to predict small parts of it, but there's a whole world of ideas and behaviors that get unleashed by immortality, and a non-trivial percentage of them are probably counterproductive with regards to humanity at large (immortal Putin, anyone?)