VAN GOGH CENTENNIAL : VAN GOGH; His Life and His Art <i> By David Sweetman (Crown Publishers: $30; 368 pp., illustrated) </i>

Where many other writers have judged instability and inherited terrors as central to the development of Vincent van Gogh’s genius, David Sweetman, author of the biographical “Vincent van Gogh: His Life and His Art,” protests. “No matter what (Van Gogh) suffered,” he writes, “despair was never the dominant element in his thoughts and his suicide does not alter that.”

In a few instances, the author even seems to tip the balance of evidence, just to avoid despair-mongering (as when he reports Gauguin’s largely discredited version of the sliced-ear incident, or suggests that Van Gogh’s point-blank shot to the left side of his chest may have been a “bungled gesture” not intentionally suicidal). The attempt is unconvincing. Overall, however, Sweetman’s feet-on-the-ground, custodial approach to his subject offers more of real value than it withholds in controversy.

Sweetman, a British art historian-BBC producer, is a sensitive, wryly humorous writer who plainly has devoted much thoughtful research to social environment and to the curious amalgam of accident, ambition and hard labor that transformed a hapless, “weedy little man . . . hissing through his teeth” (as described by a fellow art student) into a master of grace.

The book draws us confidently into a never-simple web of personal and social dynamics and historical detail in a way Van Gogh’s art work (which eschews realistic detail) and his letters (which often describe states of mind not borne out by the work) cannot. For example, we learn at one point that Charles Verlat, the imperious, disapproving director of an art academy Van Gogh attended, happened to be “a master of . . . dead classicism” who nonetheless “disgraced himself by painting 13 spokes on a chariot wheel,” and whose hobby was making little pictures “in which monkeys played human roles.”

The talented and radical Van Gogh, too, painted for complicated reasons. The famous portrait of his pristine, golden bedroom in Arles was, for example, “a fantasy” of domesticity, made in preparation for Gauguin’s arrival there--a picture of comfort to ward off the “rising tide of debris” in his real rooms and the loneliness he really endured amid the “hermetic society” of Provence.

Protective yet realistic, armed against mythologizers while attending carefully to the oblique meanings of the artist’s habits, associates and whereabouts, this biographer is the voice of the fond, sensible and intimate older brother that the living Vincent van Gogh lacked.