I should perhaps also note that I try, whenever possible, not to collect raw quotes or information simply copied from the Internet or from books, but to write excerpts or summaries in my own words on the basis of my reading. Luhmann called this "reformulating writing" and argued that such an approach is most important for one's own intellectual life. But this idea is not a new discovery Luhmann made. In fact, the idea that excerpts should be used to keep on's research goes back to at least the Renaissance when people first began to make extensive excerpts on paper.