An incomprehensible screed of words carved by a grief-stricken schizophrenic French farmer into his bedroom floor has become Paris's most controversial new art exhibit.

Since the Plancher de Jeannot (Jeannot's Floorboards) went on display last week, it has created an unprecedented stir. 'People are terribly disturbed by it. Some feel it should not be on public view,' said Claudine Hermabessiere, spokeswoman for the Bibliotheque Francois Mitterrand. The carving - 80 lines of text, in capital letters with no punctuation - contains references to Hitler, to Popes and to an infernal machine that controls humans.

'The work raises painful questions about whether madness can be artistic. The people who are most upset are those who know Jeannot's story,' said Hermabessiere.

The journey to artistic fame of the 24ft by 9ft oak floor is as strange as its message. Jeannot, whose surname and Pyreneean village have been kept secret, was born in 1939 and lived with his parents and his two older sisters, Simone and Paule. After their father's suicide, Simone married and left home but Jeannot and Paule stayed there with their mother. In 1966, Jeannot opened fire on his neighbours' dining room, after voices had told him to kill them.

When a doctor committed Jeannot to a mental institution in 1967, a team of 30 gendarmes could not get him out of the house. In December 1971, a local vet found his mother dead in her armchair. Jeannot insisted she should be buried under the kitchen stairs, with a ball of wool, knitting needles and a bottle of wine.

Jeannot moved his bed to the dining room, next to the stairs, and began carving the oak floor: 'Religion has invented machines for commanding the brain of people and animals and with an invention for seeing our vision through the retina uses us to do ill (...) the church after using Hitler to kill the Jews wanted to invent a trial to take power (...) we Jean Paule are innocent we have neither killed nor destroyed nor hurt others it's religion that uses electronic machines to command the brain.'

Seven months after his mother was buried under the stairs, Jeannot starved to death. Paule lived until 1993 when a neighbour found her body in the pigsty. The bric-a-brac merchants who came to the house at the request of Simone's family found the carved floor.

Although art critics want the work to continue to be seen by a wide audience after its stint at the Bibliotheque Nationale, Benoit Gallet, a spokesman for the Bristol Myers Squibb pharmaceutical company which owns Jeannot's Floorboards, said: 'We intend to offer the work to the Hopital Sainte Anne, a psychiatric centre in Paris. We feel that placing the work in that environment will help fight against the stigmatisation of mental illness as people will want to go in and see it.'