I've also been running a nonfiction book club that reads popular science for 7 years now. It's always been OK in our group to only have read part of it, or to h

I've also been running a nonfiction book club that reads popular science for 7 years now. It's always been OK in our group to only have read part of it, or to have watched an author talk or PBS documentary version. Nonfiction books mostly can't be spoiled, and it's possible to talk about the author's thesis by having just listening to a talk. Also, some books just don't lead to much discussion because they don't have any overarching theme -- some are collections of anecdotes and short episodes that are often fun to read but don't provide much to talk about beyond "what did you learn that most surprised you?" or "which section was your favorite?"