Lightness is the subtraction of weight from the figures, the city, the story, so that representation becomes agile and precise rather than heavy and opaque. It is not vagueness or flight from reality but a method of approaching the world through its lighter aspects, as Perseus looks at Medusa only in the mirror of his shield.
Language tends toward a slackening that reduces expression to generic, abstract, washed-out formulas, which Calvino calls a pestilence afflicting words. Exactitude counters this by insisting on a well-defined work design, sharp visual images, and language precise in word choice and in rendering nuances of thought and imagination.
Quickness is an economy of narrative in which the swiftness of connection between events, and the rhythm and logic that carry a story forward, matter more than literal brevity. Digression and delay can serve this quickness because they multiply the time inside a work while keeping the mental movement agile.
Calvino proposes lightness, quickness, exactitude, visibility, and multiplicity as the literary qualities worth preserving into the next millennium, treating each as a working value rather than an absolute. Each is defined against a specific threat (weight, sluggishness, vagueness, loss of imagery, closed singularity), so the set functions as a diagnostic checklist for what writing is at risk of losing.