Brad DeLong writes about The Eighteenth-Century Rollback of Intellectual Property and quotes from “The Pleasures of the Imagination: English Culture in the Eighteenth Century” John Brewer (1997):
As one of the judges put it… ‘the very matter and content of… books are by the author’s publication of them irrevocably given to the public; they become common; all the sentiments contained therein, rendered universally common; and when the sentiments are made common by the author’s own act, every use of those sentiments must be equally common.’
I love his view that the very act of publishing is a giving away of the idea itself. In so many cases, we pass it on with a second thought: if I tell you a joke, do you not repeat it later? If I invent a turn of phrase or wear my cap on backwards, do you not imitate? If I hold doors open for old ladies, do you not copy me?