Schopenhauer referred to him as his "spiritual brother"; Italians consider him one of their greatest ever intellects, and his thoughts have been said to "go beyond those of every other European man of letters, from Goethe to Paul Valéry".
Yet, despite these many accolades, the 19th-century poet and philosopher Giacomo Leopardi remains unknown in the mainstream anglophone world.
"If today I say to a non-Italian scholar that the Canti are no less beautiful than the poems of Hölderlin or Goethe or [Baudelaire's] Fleurs du Mal, and I insist that the prose of [Leopardi's] Zibaldone is no less unsettling than that of Nietzsche, no one believes me," wrote the writer and critic Pietro Citati recently. "And yet that is exactly how things are."
After seven years of toil involving a team of translators in three different countries, however, that may be about to change with the publication in Britain on Thursday of the first complete English translation of Leopardi's famous notebook, the Zibaldone di pensieri.
A collection of the writer's ideas, observations and analyses over 15 years, the Zibaldone, or Hodge-Podge, as it is affectionately known by some, was published in Italy at the turn of the 20th century – more than 60 years after its author's premature death – and until now only parts had been put into English.
The new edition, produced under the auspices of the Leopardi Centre at Birmingham University, is the full, unexpurgated classic, and stretches to more than 2,500 pages.
"It has been very, very challenging because it's a very long text – huge, full of quotations in Greek Latin, French, Spanish, English," said co-editor Franco D'Intino, professor of modern Italian literature at La Sapienza University in Rome.
"One cannot master all that Leopardi mastered – that's the point. There is so much that he could understand that you cannot because you are not an encyclopaedic man of the 18th or 19th century. He was a genius, and I am not!"
Born in 1798 in a small town in what was then the Papal States, Leopardi is considered by many to be one of Italy's finest lyric poets, second only to Dante. D'Intino considers him "the Dante of modern times – the thinking poet, the moral and the metaphysical poet".
Despite his secluded upbringing, his writings, even those in his early years, posed questions deemed radical for his time. They showed an influence by the enlightenment and in many ways herald the nihilism of Nietszche.
Leopardi was a precocious talent, devouring languages both ancient and modern as a young man, and writing his first Canti by the age of 20. However his life came to be blighted by ill-health and he died, aged 38, in 1837. He wrote his last lyric poem, The Waning of the Moon, shortly before his death.
Published by Penguin in the UK, the edition was also released on 9 July in the US by Farrar, Straus and Giroux, whose president and publisher Jonathan Galassi translated Leopardi's Canti to wide critical acclaim in 2010.
Michael Caesar, emeritus professor of Italian Studies at Birmingham and the Zibaldone translation's other co-editor, said he hoped the book would elicit the curiosity of anglophone readers and introduce them to one of the lesser-known European greats.
"Leopardi is surprisingly modern, in the way in which he reasons, in his alertness to what is going on in the world around him, but also in the way in which he's in many ways implicitly or explicitly predicting how things will go in the future," said Caesar. "He has an idea of a human society that is almost entirely divorced from its origins or indeed from its environment … So he is definitely one of the moderns, even if he is a modern who is absolutely steeped in classical and early scientific thinking."
Writing in the Corriere della Sera, Citati, a biographer of Leopardi, said the Italian was an "essential figure" who was largely missing in other cultures. Of the translated Zibaldone, he added: "I hope the work has great success, and that it leads to the publication of all Leopardi's works in every language."
