The Value of Continued Existence
Imagine that you were to learn that, shortly after your death, the human race would be destroyed. Let's say that a massive long-period comet was going to strike the earth. You are going to live out the rest of your life - the comet is not going to kill you. However, the rest of humanity would die shortly thereafter.
Would this alter your life plans?
In my case, I know it would. I would find these blog postings to be quite a waste of time. I would regret that I had spent so much time on them at all - all of that time writing, reading, and thinking about the difference between good and evil was wasted - it has no value. It only has value if it is a part of an ongoing discussion that will continue long into the future.
Samuel Scheffler discusses this scenario in Death and the Afterlife, which was the focus of a podcast episode from the London School of Economics, After Your Death.
One of the implications of this thought experiment is that it seems to suggest that, for many of us, what happens after we die seems to be important. It is not just our children and grandchildren that matter - it is the continued existence of the human race. Without this, some of our current projects lose their value. There may be some people for whom existence itself becomes pointless.
I find this to be another example - like Robert Nozick's experience machine - that shows that people do not just value their own pleasure. They care about things that will happen even when their own capacity to feel pleasure no longer exists.
We can handle these observations with a theory that people have "desires that P" - and desires motivate agents to realize states in which "P" is true - even though P does not become true until after the agent's death. I can have a desire to participate in a philosophical discussion that goes on after my desk such that, 72 years and 4 months from now, a philosopher puts into an article something that somehow gets linked causally to a blog posting of mine, or an email that I sent - even if the author does not realize that such a link exists (or that such a person as Alonzo Fyfe ever existed). I have still had an influence . . . for the better, I hope.
Hedonism, I think, would have to introduce some gymnastics to account for these observations. It's not that it can't be done; hedonism can be manipulated to explain all human actions in the same way that Ptolomey's epicycles can be manipulated to explain the motion of the planets. It's just that there are reasons to prefer a simpler theory to a burdensome and complex theory.
The simpler theory is that the propositions P that are the objects of our desires can sometimes be made true after our death. When this happens, we are still motivated to realize those states; they give our current life meaning. We are, in a sense, better off today to a degree if the future of humanity is better off.
In the podcast, Sam Scheffler said,
We need other people to exist in the future or else our own lives are going to be less valuable now....It's not just that they depend on us and our willingness to make sacrifices. It's that we depend on them. We need humanity to be an ongoing flourishing enterprise in order to find value in our own lives.