Duchamp scholar Francis M. Naumann's new book argues that a love affair with Brazilian sculptor Maria Martins transformed Marcel Duchamp's late work, recasting a figure long seen as glacial and calculating as tender, even romantic. Impossible, published by Abbeville Press, traces the relationship from their first meeting in March 1943 until their deaths, contending the bond endured even though its most intense phase lasted under a decade and Martins never left her husband, a Brazilian ambassador, or her three children.

Naumann, who has written on Duchamp for almost five decades, builds his case through sculptures the two made for each other. He reads Duchamp's Paysage fautif of 1946, made with his own seminal fluid on plastic backed with black satin, as an intimate gift, and Martins's bronze The Impossible, III of the same year, now at New York's Museum of Modern Art, as a comment on a relationship that could not be lived. Her goddess figures from Brazilian folklore, shown at the Valentine Gallery, grew more abstract and psychologically charged as the affair deepened.

The central claim concerns Duchamp's final work, Étant donnés, the illusionistic installation of a nude woman in a landscape, laboured on from 1946 to 1966. Naumann presents it as the culmination of the affair rather than a late joke: Martins lent her body to be cast, helped choreograph its pose and advised on technique. Letters in the book show Duchamp writing of sadness at their separation and feeling lost when cut off from each other, while a notebook page bears a hand-drawn heart in red crayon dedicated to Maria.

The account has gaps. Martins's letters to Duchamp are not publicly available, so her view of the relationship remains largely unknown, despite signs of attachment: a photograph of Duchamp in her studio, another on a charm bracelet beside a lock of his hair. After her husband died in 1965 she returned to New York and visited Duchamp, by then married to Alexina Duchamp; Naumann suggests he may have signed and dated Étant donnés then, finally able to finish it once they were together again.