Methuselah's Children

Like many of Heinlein's works, this book not only provides adventure but also makes readers think, tossing off reflections on various issues throughout the novel (mostly on the part of the protagonist Lazarus Long). What I found interesting about Lazarus Long in the novel is that he's an authority--an elder--but is not authoritarian. He holds forth not to impose his views, but to help the community of immortals reach their own decisions.