How many doodles have you made on Post-it notes and corners of newspapers while listening to someone jabber down the telephone?

Could you ever imagine they might be ground-breaking art?

For visionary outsider Jean Dubuffet, the automatic drawings he made chatting on the phone in his Paris flat during the 1960s were the purest form of expression he could imagine.

He turned his doodles of a coffee pot, a cow, a mosquito and an umbrella into a series of loose, abstract pictures, which formed part of a 12-year-long L’Hourloupe series and were initially printed in a book of the same name.

“They show what is possible if the mind is allowed to run free. He realised they were pure thought,” explains Katy Norris, the curator behind the first exhibition of the French artist’s work for 50 years, on display at Chichester’s Pallant House Gallery until February.

Etymologically speaking, L’Hourloupe takes its name from the French word entourlouper (to make a fool of) and also embraces the title of French writer Guy de Maupassant’s short story, Le Horla.

Maupassant’s horror story – its own title a neologism combining the French words hors (outside) and là (there) to mean the outsider or the one out there – deals with bourgeois alienation and a man’s descent into madness.

Dubuffet was fascinated by, and identified with, people who he considered to have alternate visions of reality. He is the man who coined the term Art Brut to describe the collection of “raw art” made by untrained artists he considered “unscathed by artistic culture”.

“There was a history of people looking at the work of the mentally ill in very separate ways, maybe just people in psychiatric wards, and he in some ways joined the whole thing together,” says Norris, explaining how the show complements the gallery’s Art From The Margins season and dovetails with the open-entry exhibition for artists outside the mainstream art world, Outside In: National.

“Dubuffet had a broader way of looking at it and turned the phrase Art Brut, meaning raw, uncooked art, made by people who hadn’t been trained in those ways of seeing and drawing that meant they could do it for the first time fresh.”

He had the term in mind as early as 1945, even before he visited Switzerland to collect work by prisoners and patients on psychiatric wards after returning to art late in life.

As a young man he had dropped out of art school, the Académie Julian in Paris, and become a successful wine merchant. It was not until the age of 41 he committed to paint again.

The experimental paintings, drawings and sculptures he produced after this point were created with deliberate disregard for his academic training.

“He wanted to unlearn what he knew. He was a cultivated person. His ideal was being this other way he could never really be.”

What drove him was the belief that work by marginalised and self-taught non-professionals subverted traditional ideas of beauty.

So he set up the Compagnie de L’Art Brut in 1948 and made an independent space away from the establishment to display his Art Brut collection.

But he saw little connection between his own work and Art Brut. He wanted the two kept separate.

“His style is a different thing,” says Norris. “He was the keeper of these people and keeper of the concept.”

In 1951 he made the decision to send his collection abroad, to New York, and, after a long gap, decided to focus on his own work.

By the end of his 50s, he had remembered the power of the work and had it returned to Paris.

“That is where we pick up with the exhibition,” says Norris.

“It was then that he launched into L’Hourloupe.”

He would cut and paste the doodles on to the pages of a book to create a jargon and language of his own.

The aim was for one completely pure idea on the page, which he would cut out and mount on to a black backing.

“He then made jargon text mocking language and you can half recognise words.

“They are very playful and in 1963 he had it reproduced as a printable book.”

The exhibition has a number of these maquettes (mock-ups), which inspired pictures such as Main Leste et Rescousse, on loan from Fondation Dubuffet in Paris.

Works from a series just prior to L’Hourloupe, the Paris Circus series from 1961, are also on display.

These mark the beginning of his transformation to L’Hourloupe.

“It was very much to do with concrete appearance. He used thick paint, crowded faces of people looking at the manifestations of the city, and then there is this jump to an exploration of his mind and memories and imprints of objects,” adds Norris, who says Affluence, from 1961, with its bursting energy and assertiveness reveals a brave pioneer.

“He was never concerned with depicting something realistically but in the Paris Circus series there is the feeling of tangibility which rapidly becomes the abstract works in L’Hourloupe.”

As the English art critic and curator Lawrence Alloway observed in 1966, L’Hourloupe recalled the “clenched order of the schizophrenic artist… a turning away from the world and a fantastic alternative to where we are now”.

  • Pallant House Gallery, North Pallant, Chichester, until Sunday, February 3. Tuesday to Saturday: 10am to 5pm, Thursday: 10am to 8pm, Sunday: 11am to 5pm, closed Monday. Call 01243 774557