I believe that the (very) far future is likely to be very important, and that my decisions today probably have (very) long-lasting effects. This suggests that I ought to be mindful of the effects of my actions on the very far future, and indeed I am most interested in activities that I think will have positive long-term effects. In contrast, many or most thoughtful people consider it unproductive to think more than a few decades ahead, to say nothing of millions of years.
When I express this view, I often encounter intense skepticism about the possibility of having any predictable influence on the far future. Even if our decisions have some effect, can we reason about it any useful way? I believe that the answer is yes, and that we can in fact have a fairly detailed and specific effect on the very far future. In this post I want to make a very simple argument for this conclusion: if we think there is a good chance that we will ever have an opportunity to have a predictable long-term influence, as I suspect we should, then interventions which improve our own capacity (such as investment) will have an indirect, significant, and predictable long-term effect.