Forward the Foundation by Isaac Asimov

This book chronicles the development of psychohistory on Trantor despite the increasing decline of the empire and the enormous personal losses that face Hari Seldon. The book picks key moments to demonstrate, so the effect is staccato. We get to infer years of happiness for Seldon in the middle of his life, but we see him in moments of crisis. The mathematics behind psychohistory, too, are sketchy, but this lack of direction, I think, helps keep the book from feeling dated.