"Once the masterpiece has emerged, the lesser works surrounding it fall into place; and it then gives the impression of having been led up to and foreseeable, though actually it is inconceivable — or, rather, it can only be conceived of once it is there for us to see it. It is not a scene that has come alive, but a latent potentiality that has materialized. Suppose that one of the world's masterpieces were to disappear, leaving no trace behind it, not even a reproduction; even the completest knowledge of its maker's other works would not enable the next generation to visualize it. All the rest of Leonardo's oeuvre would not enable us to visualize the Mona Lisa; all Rembrandt's, the Three Crosses or The Prodigal Son; all Vermeer's, The Love Letter; all Titian's, the Venice Pietà; all medieval sculpture, the Chartres Kings or the Naumburg Uta. What would another picture by the Master of Villeneuve look like? How could even the most careful study of The Embarkation for Cythera, or indeed that of all Watteau's other works conjure up L'Enseigne de Gersaint, had it disappeared?"