A paragraph should say one thing well. I think it is best if it does not say something about many things, nor many things about something; it is proper if it illuminates a single idea, transferring that idea to the mind of the reader where, like a seed, it may possibly live, grow, and transform. Or if it may be imagined as a foot-stool, on which we may rest and support our work (or ourselves), then it may want three or more legs -- some triad or quatrain of ideas fastened together into an agreeable unity. And a well-written paragraph needs, I think, to be able to stand alone, when lifted from its immediate context -- for example, when it is quoted in another place. In that way, it may be worthy to be more than it once was -- and become a part of the Great Conversation.