WHEN René Magritte was 13 years old, his mother drowned herself in a local river. When the body was recovered her face was found to be covered with her nightdress. No one knew whether she had deliberately shielded her eyes from death or if the river current had simply veiled her face. Magritte had begun painting a year earlier.

He would become obsessed with the hidden. His paintings often include grey rivers, pale lifeless bodies, faces swathed in fabric, solitary men walking, sea water and rampant roses—as well as the floating apples, burning bassoons, fingerless arms, sponges and pipes that began to appear in his work after he met Giorgio de Chirico, an Italian artist, and converted to Surrealism.

For nearly a century fans of Magritte have studied his works, determined to find hidden meanings within them. But the man himself fiercely resisted interpretation. He wanted his pictures to be looked at, he said, not looked into. Yet the temptation to probe persists, which is one reason why Sotheby's sale next month of a cache of more than 40 letters by Magritte—unseen for nearly a quarter century—is exciting so much interest.

The letters, most of which are undated and not included in the collection that was published in 1994, span more than 20 years and cover a wide range of topics—artistic, literary and surreal. They are all addressed to Paul Colinet, a Belgian poet who worked closely with Magritte and who, for a long time, was also the lover of Magritte's wife.

Magritte had met the pretty Georgette Berger when they were both schoolchildren. Their marriage was childless, but famed for its constancy. Her affair with Colinet was her only transgression and seems to have been encouraged by Magritte while he was away in London in 1936, developing a relationship with Edward James, ultimately one of his most important patrons, and possibly having a brief dalliance of his own. “I want you to do wherever possible whatever you can to make my absence less distressing to my wife,” he wrote Colinet. Magritte could not keep up this phlegmatic act, however. On his return, he persuaded a policeman to accompany him as he followed the couple to the inevitable confrontation. For a while the two men fell out badly.

The artist and the poet had met three years earlier and quickly became close friends. Colinet's first published work, a poem set to music, bore a suitably Magrittean title, “Marie Trombone Chapeau buse”, and contained an illustration by the Surrealist painter. Yet these letters reveal that it was Magritte who came to depend on Colinet, rather than the other way round.

Magritte's letters to Colinet were recovered from his studio by Georgette after his death and sold at auction in London in 1987. They were bought by an American businessman, who thought that at £12,000 ($20,076 at the time) they were a steal. He has kept them in a safe ever since. They are now being offered with an estimate of $200,000-400,000

In writing, Magritte is unremittingly cheery. Unlike most artists he never spills into bilious complaints about lack of money, scheming gallerists and the dimness of the art-viewing press.

He discusses at length a picture of a hen and boiled eggs, which was finally painted in a different form as “Variantes de la Tristesse”, asking whether Colinet thinks the egg should be intact or “decapitated”. He frequently seeks Colinet's advice on naming his pictures, and praises the poet's talent for picking titles. He includes a sketch and asks for several alternatives with the words “un titre plaese! (prononcer un ‘titre plisse')”. On a small landscape, Colinet writes in green ink: “Les Bonnes Nouvelles”, “La Presence d'Esprit”, “La Science du Mouvement” and “L'Art Magique”.

The letters are full of sketches that show Magritte's vivid imagination. He plays with numbers (digressing on the significance of the number nine), offers fierce opinions (on Martin Heidegger and Jorge Luis Borges, among others) and decorates the text with a wide array of sketches. The most amusing is a drawing of a giant boater, so big it's almost a marquee, with lots of people stashed away underneath it, and a note of personal instruction from Magritte: “Pensé aussi à un chapeau pour plusieurs personnes.”





Réné Magritte's correspondence with Paul Colinet will be sold at Sotheby's in New York on June 18th as part of its Fine Books and Manuscripts sale.