We know of only three texts written by André Cadere, this is the only one that was not yet published. Between May and July 1978, in the weeks preceding his death, he wrote forty-three letters to his friend and gallery owner, Yvon Lambert. These letters – a moving testimony to his thinking, his practice and his work – are published here for the first time in their entirety, and constitute the artist’s third and last writing, after Presentation of a work. Use of a work (1974), and History of a work (1982). The edition is composed of a slipcase that gathers the book introduced by Bernard Marcelis – specialist of Cadere, author of his catalogue raisonne? – followed by the 43 letters commented, annotated and illustrated.