Henri Michaux.

WHITECHAPEL ART GALLERY, LONDON

Most writers are more or less secretly envious of the painter's or sculptor's good fortune in being able to deal with physical stuff you can push around, rather than the infuriatingly inward substance that is language. (This envy is based on an illusion, of course. Language only seems more inward a medium than the others.) But there are few writers who actually go beyond dabbling in art - or writing reviews of it. Henri Michaux was one of that rare clan, the writers-turned-artists.

Michaux combined, improbably, something of Antonin Artaud's capacity for suffering with Jean Arp's subversive equanimity, and - perhaps thanks to his abandoned medical training - something too of Andre Breton's clinical curiosity about his own mental processes. Born in Belgium, a country he detested, Michaux became a naturalized Frenchman, but photographs, like the touching portrait by Brassai reproduced in the Whitechapel catalogue, show he remained the severe and phlegmatic Walloon. In fact, he was never at home anywhere, and traveled incessantly, not for pleasure or even to satisfy his curiosity, but in order to make himself an alien, with its attendant discomfort - to be "a barbarian in Asia," as he called one of his books, a stranger in Africa, South America, or anywhere. Eventually he would find a definitive means to achieve pure alienation in his own head, by means of mescaline.

The earliest works here date from 1927, around the time of Michaux's first serious literary efforts. Executed in ink, these drawings, titled Narration and Alphabet, suggest texts handwritten in characters that only appear once, if such a thing were possible. Michaux's draftsmanship was born out of an urge to depict the strangeness of writing - to produce something even more opaque than the invented words in his poems of the period, just as those words amplify the vivifying effect he had found as a child of isolated words in the dictionary, where "words . . . do not yet belong to phrases, to phrasemakers." Awkward, without flow, these early pieces are clearly the work of an amateur, expressing more a frustration with writing than a facility for drawing.

It was in 1936 that Michaux seems to have set seriously to work at painting, now primarily in gouache, leading two years later to an exhibition whose announcement proclaimed: "Un poete se change en peintre" (A poet turns into a painter). Yet, as if the white page were still inexorably the field of writing for Michaux, he painted many of his gouaches of the late '30s on black paper. They are fantastic, richly colored nocturnal landscapes, sometimes peopled by odd little figures. It's not surprising that Michaux cited Paul Klee as the first artist to shock him out of a loathing for painting, once expressed as: "As if there still weren't enough of reality, of that awful reality. . . . But to want to repeat it, to come back to it!" These works, like his renderings of phantasmic heads and other quasi-figurative works of the '40s (by which time he'd returned to the use of a white ground, though only on the condition that it be sufficiently soaked for his inks and watercolors to merge with it), clearly parallel Michaux's books of this era, which describe invented cultures, at once extending and parodying his own imaginative travel writings. They have a charm his later creations would eschew.

Michaux's works in ink from the '50s and '60s, usually seen as part of the broader current of tachisme, brought together his early fascination with the cusp between drawing and writing and his later play with the ambiguity between abstract mark-making and figurative suggestion; his long attraction to Asian cultures - in which painting, drawing, and calligraphy are less distinct forms than in the West - finds its fruition here too. Francis Bacon once called these works superior to Jackson Pollock's. Though I wouldn't go that far, they have a power to draw you into their realm of teeming signs broadcast across the page, using characters "which always convey you back to the human image - a human image generally dragging and trudging through deep plowed fields, or something like that," as Bacon told critic David Sylvester. These masses of obliquely humanoid strokes convey an almost paranoid intensity, and also its opposite, a cool and imperturbable lightness and distance.

But these works are restrained compared to the mescaline drawings and "post-mescaline" drawings of the same era. (Michaux assigned neither titles nor dates to his mature work, considering them by-products of an ongoing investigation rather than self-contained pieces, and Whitechapel has followed the artist's lead, broadly gathering these drawings by theme or time period.) Anhedonic as ever, Michaux began his hallucinogenic experiments in 1954 in anything but the spirit of what we now call "recreational." He was searching for the foreign territory within himself. And though he stated that "a hand two hundred times more agile than the human hand would not be up to the task of following the speeding course of the inexhaustible spectacle" he discovered, it looks to me like he not only found that vast and endlessly transforming landscape, but claimed it. Here, the ever more minute marks - monstrously profuse and relentlessly focused - have nothing to do with human form, but seem to reflect a sort of mineral yet vibratory substratum of being. And though a few of these sheets are nothing more than handwriting going off the rails, becoming incomprehensible before one's eyes, most have nothing to do with writing, and little to do with depiction. They don't evoke apparitions, but rather their opposite: vision ground down to its molecules.

Barry Schwabsky is the author of The Widening Circle: Consequences of Modernism in Contemporary Art (Cambridge University Press, 1997).