Few books worth reading can be summed up in a single sentence. It's been said that brevity is the soul of wit, but an enlightening and insightful and informative book isn't going to lay out the main idea in such a simplistic manner that it can be laid bare in so few words. To really and truly understand a concept, one needs to have a solid foundation in the fundamentals of what goes into that idea and one needs to have clear examples of how that concept can be broken down, how it can be viewed from different angles or on multiple levels, and how it can be applied. That's why books aren't pamphlets. That's why authors need to put more time and effort into researching and presenting their conclusions, and that's why if you want to wrap your head around them and get your money's worth, you'll have to put in the time and effort to read them. Even if I were to furnish you with a dozen of the main points or arguments presented in those books, without the accompanying background information and illustration of those points, they'd be worthless to you. Not to mention that most works of non-fiction do not revolve around or boil down to any one particular and specific theme, but instead they raise a host of questions or explore a wide array of different things. So either read them and enlighten yourself or continue on with your de-cluttering and deny yourself the opportunity to get anything out of them. It's your choice.