Stupid or lazy people like to substitute real thinking by quoting others who do think. The intention being to create the illusion they are themselves intelligent by proximity.
Most people are not original thinkers. There really is no such thing as an original thought. We all "quote" and discuss ideas we have read, whether in a book, article, or from a learned teacher. Most scientists built theories by studying other scientists. As Newton said, "If I have seen further than others, it is by standing upon the shoulders of giants." Any thought you have right has been someone somewhat shape or modified via information from a variety of sourced (books, articles, tv, teachers/professors, etc).
