"Steal like an artist" or "If you want to be a great artist, you must learn how to steal" and similar are words of wisdom by some of the greatest artists of all time. It broadly refers to the fact that all themes and stories (and artwork) are derivative in one form or another. But I don't think this doesn't necessarily stop there. Just a lazy example, in 'Harry Potter' JK derived various aspects of the plot, characters and milieu from a variety of well-known books and stories, as did LOTR and "Hunger Games'. Like I said, lazy examples, but I saw outraged fans analysing chapters and paragraphs that come dangerously close to what's been already written by someone else, and my first instinct was to be quite appalled. But, it turned out, it wasn't plagiarism and billions of their fans didn't care at all. They all earned obscene amounts of money and are well respected writers. They learned to steal like artists? What I'm wondering is, what if you find a paragraph in someone's novel that perfectly expresses what you need to say in yours. And even if you modify and change it to suit your narrative, the logic behind the words and the thought progression are derivative. You can't be accused of copying verbatim at all, but what you wrote is based on something else, a bit more closely then just a 'general theme'? Should we or shouldn't we?