In the third act of Hamlet, Shakespeare erects a stage on the stage; the fact that the play enacted there–the poisoning of a king–in some way mirrors the primary play suffices to suggest the posibility of infinite involutions. (In an 1840 article, De Quincey observes that the stolid, heavy-handed style of this minor play makes the overall drama that includes it appear, by contrast, more lifelike. I would add that its essential aim is the opposite: to make reality appear unreal to us.)

– Jorge Luis Borges, From his essay “When Fiction Lives in Fiction”