While living in Paris's Saint-Germain-des-Près in 1951, Le Maréchal wrote poems and drew ghost houses in dead cities. He made his first visionary paintings, including La mécanique mange les maisons, in Morocco, where he lived for a year. In 1954 he rented a room in London and painted Angoisse-palace and L'Amour au bordel populaire. Back in Paris, he showed his work to Gaston Bachelard, who saw that, to a philosopher, they were, "the seeds of infinite reveries," and in the catalog to Le Maréchal's 1957 exhibition at Galerie Éric Losfeld wrote, "Le Maréchal's cities are built on earthquakes." Le Maréchal, in rebellion against the reality of technocrats, pursued his work in secret, producing large oil and tempera paintings on wood panels with titles that read like proclamations: Le Temps se retoume monté sur le signe de rinfini. Pas de Jugement (1959) (Time turns back mounted on the sign of infinity. No Judgment). Believing that "the love of big money dashes dreams" he attacked capitalism—the powers of money symbolized by the Stock Exchange. His exhibition at Galerie Raymond Cordier, in November 1960, featured Le Triomphe de l’avidité temporelle (1960), along with portraits of the demons of industrial society, such as Le Groom de la fabrique, grand vainqueur de la guerre et grand responsable des guerres du futur (1960) (The groom of the factory, great victor of the war and the main cause of future wars), with a catalog essay by André Breton. Later, Le Maréchal studied zinc engraving with DoIf Reiser and handled aqua fortis with such impetuosity that he was compared with the romantic engraver Charles Méryon, especially since, like Méryon, he inscribed vehement comments in the lower margin of his prints. André Pieyre de Mandiargues was impressed by the engravings Le Marechal executed from drawings of England—particularly his view of London from Piccadilly Circus—and considered his oeuvre to be "a two-sided mirror where the least compatible extremes easily converge." Mandiargues further elaborated thus: "The fire of the most authentically poetic inspiration often passes through this boisterous, roaring universe like a splendid comet. Le Maréchal evidently received the gift of such an imaginary power that in this regard we would have a hard time finding his equal today." Le Marechal's revolt against the idols of progress was expressed in such powerful imagery that his exhibition in May 1968, at Galerie lnna Salomon, appears to evoke the very spirit that animated the student demonstrations of that year. But with his reclusive temperament, Le Maréchal continued to work in solitude, leaving some of his paintings uncompleted, as though they were merely hints or traces of his boundless inner adventure. In 1983 Le Maréchal had an exhibition at Galerie Michèle Broutta, titled Catalog of the Engraved Works 1956-86, ending with two images of Buddhist meditation "for Westerners" that represented Mount Kailasa, the mountain with ten thousand names, the center of all countries."
L'Imperceptibile Abîme, Ink on Paper, n.d.