In addition, of those thousands of pages, some 3,197 (around two-thirds of the total) were written in just two years, 1821 and 1823. After a slow, uncertain start the pace accelerated rapidly; then, in the course of ten more years, it decreased and came to a stop. If we consider the extraordinary intellectual and philosophical range of the Zibaldone, it’s hard to remember, reading it, that it is the work of a very young man, even if one who was a genius.

The second significant fact has to do with place: Leopardi remained at Recanati until July 1825, with a short Roman interlude of several months, from November 1822 to April 1823, during which he wrote barely forty-one pages. Between 1825 and 1830, he left on two further occasions, staying away from home for months at a time, at irregular intervals (July 1825–November 1826, April 1827–November 1828) until his final departure for Florence in 1830. So when he was away from Recanati he wrote, in all, barely 262 pages. The end of isolation first altered the rhythm of the writing, then broke it for good. The last entry written in Recanati is on page 4,524: after that, a leap into the void, as he went first to Florence, then Rome, and, finally, Naples, where he died. The enormous manuscript accompanied him everywhere on that last journey, but he added only a few more lines.

The library of the house where Leopardi grew up was therefore the birthplace—and also the deathbed—of the Zibaldone: the only place where this fragile organism could grow. If in Recanati the young Giacomo was cut off from the world, the richly endowed library protected him from both modernity and isolation, offering him, as if on a three-dimensional interactive screen of the future, the illusion of a faraway space and time, the company of virtual persons, the sonority of voices that, though dead, came alive in the thousands of volumes that filled the rooms of the second floor of the palazzo. The Zibaldone came into being so that Leopardi could have a dialogue with those voices, participate in that second life: he was the ancestor of those adolescents who today construct an identity in front of the screen, and it shouldn’t surprise us if the result of this psychic attitude is the first modern philosophical hypertext.

There has been a great deal of discussion about the sources of the Zibaldone and its possible models (the word, of uncertain etymology, means “miscellany” or “notebook” or “collection of occasional thoughts and notes” or even, less grandly, “a hodgepodge”). The influence of Joseph Anton Vogel, one of Leopardi’s teachers, has been rightly appreciated: Vogel embodied the tradition of the ars excerpendi, that is, the sixteenth- and seventeenth-century techniques of filing and rationally organizing knowledge in catalogues and indexes. These methods were used extensively by Leopardi from early youth for his philological and scholarly works: tiny cards that assemble quotations, lists, page numbers, key words, verses that link concepts—a real workshop of the art of memory. It was not so much the ancient ars memoriae, however, which was useful for oral communication, but, rather, a more modern derivation, connected to the world of writing and printing. Leopardi’s voracity as a reader is proverbial; but if we observe his laboratory from up close we can see that he was schooled above all in what today would be called data banks: anthologies, dictionaries, archives of texts, encyclopedias, commentaries, indexes. He kept open on his worktable the Latin and Greek lexicons, Du Cange, Forcellini, and Scapula; the great collection of Fabricius, inspired by the Polyhistor of Morhof; the collections of Meursius and Graevius, which led to inexhaustible bibliographical pathways and opened the doors of hidden treasuries of quotations. The real library thus became a virtual library, similar to the Internet, and it’s not always clear if the reference is to texts read at first or second or third hand. Nor is it clear—the critics continue to argue—whether the writing of the diary was immediate, or if it was preceded by drafts or preparatory notes. It’s likely that the truth lies somewhere in the middle: different methodologies according to the nature of the subject and the circumstances. Certainly Leopardi used file cards, some of which have come down to us.

Thus in the scholarly works that preceded the Zibaldone (in particular Storia dell’Astronomia and Saggio sopra gli errori popolari degli antichi) Leopardi learned to record, as if on tape, fragments of voices, so that he could bring them to life again in his mind. The private writing that he started doing in 1817 is a more radical and freer response to this need, with a paradoxical result: the Zibaldone is a work of absolute writerliness, produced in the silence of a library, yet it has a profound oral and dialogic tension—one has only to read the first page, which is so rich in sounds, voices, stories, anecdotes, and dialogues, and observe how colloquial forms mimic a real discussion (Z 4252). Over the years, the manuscript became the secret place where Leopardi could summon authors at will to question them (this is one of the original meanings, in the law, of the word citation); it is reminiscent of the oral matrix and the dialectical forms in which intellectual exchange took place among the ancients. One thinks of the symposiums, of the almost physical tension that emerges in some of Plato’s dialogues; and also of the works of a later period that Leopardi loved, full of voices, anecdotes, polemics, and stories—Plutarch, Clement of Alexandria, Diogenes Laertius, or the Athenaeus of The Deipnosophists, with a commentary by Casaubon, annotated in turn by Giacomo.

The dialogic tension takes very diverse forms. In the periods when other libraries were available to him (for example, in Bologna or Florence), Leopardi, eager for texts he didn’t own, concentrated on taking notes on his reading. But here, too, the perspective is that of a dialogue: Leopardi had a profound respect for the texts he cited—always in the original language—and copied them with extreme care, giving all the facts with the greatest precision. He almost never paraphrases, he never replaces his interlocutor, but he often interrupts him to say what he thinks: the Zibaldone is sprinkled with parentheses in which Leopardi translates (himself or in the voice of another translator), explains, annotates, offers alternative solutions, clarifies, comments.

When he has more time, that is, in general, at Recanati, the words of others produce an immediate, more substantive reaction: comments and arguments, often followed by new quotations and new comments, in many cases addressed to an imaginary public. The outline of such discussions (real hand-to-hand contests) can vary: with some texts he has a brief, intense, and definitive encounter; with others there is a prolonged battle, preceded by an introduction or followed by further skirmishes, at a distance of months or years; and in certain periods all or nearly all the notes are secretly guided by a reading that comes to the surface only in part (for example, the Politics of Aristotle, in the fall of 1823). Leopardi’s temperament was both heroic and neurotic-obsessive. He would never leave the adversary master of the field out of weariness, inertia, or distraction but goes forward implacably until he feels satisfied, at least provisionally, until the next duel. And the more obscure the struggle, the more violent; if the adversary is hidden, it usually means that the stakes are higher. The authors he confronted most intensely are specters who surface apparently by chance, obliquely, but they are, like Hamlet’s father, all the more crucial for the action.