American literary critic, author and scholar, William Lyon Phelps ( 1865 – 1943) was a professor of English at Yale University from 1901 to 1933, where he taught a course on the Modern Novel. In a radio broadcast on April 6, 1933, he delivered “The Pleasure of Books” speech:

The habit of reading is one of the greatest resources of mankind; and we enjoy reading books that belong to us much more than if they are borrowed. A borrowed book is like a guest in the house; it must be treated with punctiliousness, with a certain considerate formality. You must see that it sustains no damage; it must not suffer while under your roof. You cannot leave it carelessly, you cannot mark it, you cannot turn down the pages, you cannot use it familiarly. And then, some day, although this is seldom done, you really ought to return it.