One day Eco is having a few glasses of wine with some friends and they think up a parlor game the point of which is to imagine disciplines that not only do not exist . . . but also cannot exist because they are impossible, for history or logical-epistemological reasons. Among these the art of forgetting, which he calls ars oblivionalis, occurs to him. Immediately he writes a conference paper – thoroughly serious, moreover – in which, using a strict semiotic method, that is, one based on the theory of signs, he seeks to prove that there can be no art of forgetting as the counterpart of the art of memory because all signs produce presences, not absences. Eco is willing at most to assign this art of forgetting a small place on the margin of semiotics, suggesting that an inordinately industrious mnemotechnics, by an exceptional success in “multiplying presences,” can eventually produce a critical befuddlement of memory that in turn has forgetfulness as its consequence. This would be an art of forgetting connected with the art of remembering only as a sort of overload relief valve … My curiosity was aroused by Eco’s suggestion that we should forget the ars oblivionalis almost as soon as he had so cleverly drawn clues that indicate that this art of forgetting, even though it should not exist, according to Eco’s argument, exists nonetheless and is encountered where we go, from Homer up to our own day.
– Harald Weinrich, Lethe: the Art and Critique of Forgetting