Not only does Judge Richard Posner define plagiarism in his little book thereon, he explains at least one reason why the concept changes and evolves. Writers used to be supported by patrons (usually wealthy aristocrats), who would know them personally, so it didn’t hurt them much if someone copied their work. Plagiarism became more of an issue once writers came to depend upon sales to a mass market. Those customers didn’t know them and might well be duped into paying someone who’d simply copied their work. “Creative imitation cannot have as capacious a scope or as positive a connotation in a modern commercial society of commodified intellectual works as it did in Shakespeare’s time.”

Is it possible that the desire to downplay plagiarism or even define it out of existence — which took most of the stage time at the Art Institute recently, as I report in this week’s Reader — is somehow connected with nostalgia for an earlier, less modern, less individualistic era?