Say you’re in the midst of writing a book, and would like to include quotes from other people, like from other authors, or maybe just other well-known people, at the beginning of each chapter to present the theme of the chapter. From one author to another, it’s a courtesy to ask for their permission to quote them. They usually welcome the quoting as long as it’s only a line or two, and will usually ask for a copy of your book when you’re finished.

And what if they’re dead?

The copyright is owned by the copyright holder plus 75 years, so the fact that they’re dead doesn’t mean it’s a fair use. Where did you draw the quote from? Did you get it from listening to them in an audience, or did you get it from a publication that they had? If they had a publication, see if that publication can give you permission. If it’s really only a sentence or two, consider it fair use.

For more quotable quotes about copyright and how to deal with citiations, check out Legal Issues You Must Know When Writing Articles For Fee or For Free.