I'd vote this up, but I can't shake the feeling that the author is setting up a false dichotomy. Living forever would be great, but living forever without arthritis would be even better. There's no reason why we shouldn't solve the easier problem first.
Sure there is. If you have two problems, one of which is substantially easier than the other, then you still might solve the harder problem first if 1) solving the easier problem won't help you solve the harder problem and 2) the harder problem is substantially more pressing. In other words, you need to take into account the opportunity cost of diverting some of your resources to solving the easier problem.
Happy New Year! Here's the latest and greatest installment of rationality quotes. Remember: