While longtermism is an interesting ethical principle, I believe the consequence of the extent of uncertainty involved with the impact of current decisions on future outcomes has not been fully explored. Specifically, while the expected value may seem reasonable, the magnitude of uncertainty is likely to dwarf it. I wrote a post on it and as far as I can tell, I have not seen a good argument addressing these issues.
https://medium.com/@venky.physics/the-fundamental-problem-with-longtermism-33c9cfbbe7a5
To be clear, I understand the argument of risk-reward tradeoff and how one is often irrationally risk-averse but I am not talking about that here.
One way to think of this is the following: if the impact of an intervention at present to influence long term future is characterized as a random variable X(t) , then, while the expectation value could be positive:
the standard deviation as a measure of uncertainty ,
could be so large that the coefficient of variation is very small:
Further if the probability of a large downside, is not negligible, where , then I don't think that the intervention is very effective.
Perhaps I have missed something here or there have been some good arguments against this perspective that I am not aware. I'd happy to hear about these.
Thanks for the response. I believe I understand your objection but it would be helpful to distinguish the following two propositions:
a. A catastrophic risk in the next few years is likely to be horrible for humanity over the next 500 years.
b. A catastrophic risk in the next few years is likely to to leave humanity (and other sentient agents) worse off in the next 5,000,000 years, all things considered.
I have no disagreement at all with the first but am deeply skeptical of the second. And that's where the divergence comes from.
The example of a post-nuclear generation being animal-right sensitive is just one possibility that I advanced; one may consider other areas such as universal disarmament, open borders, end of racism/sexism. If the probability of a more tolerant humanity emerging from the ashes of a nuclear winter is even 0.00001, then from the perspective of someone looking back 100,000 years from now, it is not very obvious that the catastrophic risk was bad, all things considered.
For example, whatever the horrors of WWII may have been, the sustenance of relative peace and prosperity of Europe since 1945 owes a significant deal to the war. In addition, the widespread acknowledgement of norms and conventions around torture and human rights is partly a consequence of the brutality of the war. That of course if far from enough to conclude that the war was a net positive. However 5000 years into the future, are you sure that in the majority of scenarios, in retrospect, WW2 would still be a net negative event?
In any case, I have added this as well in the post: