As a writer, I can tell you there is no "original" written work anymore. As we read, some things are retained in our brain subconsciously. There are those who do take other people's work, but in general we all gain knowldge from others and it is reflected in our work. I am carefule to cite, and thank, those works I use but not everyone does. You have to be careful in making broad statments, remember in most incidents a few give the greater a bad rap. Happy hunting!