The Volokh Conspiracy has a strange, albeit fascinating discussion that started out by asking
"There is an arbitrariness in defining the relevant class of risky events. In my lifetime as a driver, I stand some (fairly low) chance of killing an innocent pedestrian. Few people would argue that I should be prohibited from driving. Assume, however, that science prolongs (fit) human life forever, at least unless you are struck down by a car. My chance of killing an innocent pedestrian then would approach certainty, given that I plan to continue driving throughout an eternal life. In fact I could be expected to kill very many pedestrians. Should I then be prohibited from driving? When we make a prohibition decision, should we measure the risk of a single act of driving, or the risk of driving throughout a lifetime? Measuring the bundled risk appears to imply absurd consequences, such as banning driving for people with sufficiently long lives.
This question evolved [ed - devolved? progressed?] to a round-up of opinions on the risk-averseness of immortals, almost immortals, or individuals with no limit on natural lifespan here
The dilemma of the immortal, continued: As you may recall from yesterday, I asked whether an immortal would necessarily be considered a murderer, given that accidents happen sooner or later. Drive on the roads for a few million years, and you are likely to run over a pedestrian. A related question is whether we should prohibit such actions, such as driving for millions of years, if our rights theory forbids the imposition of high levels of risk on other people. Conversely, if we do not consider the immortal driver a murderer, we might face counterexamples where we cannot stop the repeated application of risk, when stopping such risks is an intuitively appealing thing to do, read the original post for more detail. The underlying dilemma is that once we consider an intertemporal perspective, can a theory of rights have a firmly grounded and intuitive benchmark for what counts as "too much risk"? Here are a few threads of the responses I received:
1. Sasha Volokh suggests that rights should be defined in terms of how much risk is acceptable to impose on a person in a given time period, not how much risk can be imposed overall through a longer period of time. This, of course, suggests that would-be aggressors can get away with misdeeds by spreading out their aggression over time probabilistically, I don't think that Sasha would regard this possibility as a reductio on his view. An interesting question is whether the time dimension should be treated separately from the dimension of space, and if so why. What if you spread very small risks around a large amount of space, killing someone with near-certainty? Would this be less acceptable than spreading the risks through time?
2. Lawrence Solum raised the separate question of how risk-averse a would-be immortal would be or should be. If your life is eternal in the absence of accidents, perhaps you should never leave the house. I have offered separate comment on this interesting issue.
Finally, the discussion culminated in comparison-shopping of our favorite TV and literature immortals
Would immortals-by-lifespan who were not invulnerable be very, or infinitely, risk averse? Would they be very unambitious and inactive, since there would always be time for stuff later?
I'm not going to get into the genuine intellectual issues at stake, just going to enjoy the chance to survey some SF, fantasy, and related genres of fiction.
A correspondent of Solum's says that in 'contemporary vampire fiction' vampires are extremely risk-averse. I suppose that this refers to the Anne Rice novels, none of which I've read. But it does invite an obvious question about Buffy the Vampire Slayer, which was otherwise generally very good about imagining a world that made sense given its initial premisses. Why would any vampire hang out in Sunnydale? The Master was bound into the Hellmouth, and some of his servants were bound to him. Occasionally there was a vampire who wanted the glory of killing a Slayer. But then there were the countless, often nameless, vampires who just inhabited the town and treated it as their feeding ground-- until they got staked. The Hellmouth might have attracted demons, made it more likely that new vampires would be created, and generated generic magical weirdness. But wouldn't an even-remotely-rational vampire, even one who had been created in Sunnydale, move out of town immediately upon realizing that he or she was much more likely to get destroyed there than any other place in the world? Even the glory-hounds must have thought that the glory of killing a Slayer was inordinately valuable, given that they should have wanted to avoid any risk at all of getting slain. Instead, they continued to congregate in the least rational place for them to do so.
Robert Heinlein's Lazarus Long was not highly risk-averse-- but he did not know that he was going to turn out to be immortal, and by the time he knew, his habits of mind, his aversion to boredom, had been very well-set. Many of his fellow Howards did become very conservative and risk-averse, especially those who were born after the advent of rejuvenation and who therefore knew all along that they were functionally immortal.
The characters in Poul Anderson's Boat of a Million Years have interestingly varied reactions-- some but not others become extremely conservative for parts of their lifespan.
Characters in the Highlander universe of course face a somewhat different incentive structure. They are immortal-- but know that only one of them will be truly immortal, the last one to survive the last swordfight. That creates an incentive to engage in swordfights along the way, so as to remain in practice. [NB: Yes, there are also intermittent claims about each immortal 'gaining the power' of each other one he or she kills in combat-- but there's not a lot of consistency about just what that means, and whether that 'power' makes one more likely to win the next fight.] Accordingly, we again see variation in strategies adopted, from the strategy of spending centuries at a time on holy ground (off limits for swordfights), in order to protect one's immortal life, to the strategy of fighting all the time in order to hone skills and increase the chances of being the last survivor.
Read the rest of the post to learn various theories about Elvish (LOTR) lifespans, and more theories on why vampires stay in Sunnyvale, while they obviously should be in Cleveland, or at least L.A.
I can only contribute to this discussion that Douglas Adams clearly thought some immortals would be rather pro-active in meeting some impossible but time-consuming goal, like meeting every person in the Universe.