Though full of subconscious upwellings and startling conjunctions of seemingly unrelated objects, Rene Magritte's paintings are not dreamscapes, according to French art critic Meuris. With every painting, the Belgian surrealist, whose work is ``governed by `thought,' '' challenges his viewer's intellect and assumptions about reality. Observes Meuris in Magrittian fashion: ``Magritte is not a painter, while yet being a great painter.'' While the paradox of the paintings of burning tubas remains largely unsolved, other images are successfully unraveled and the heavy French intellectual baggage one might expect is avoided. Meuris also looks at Magritte's little-known photographs, short films, sculptures and surreal objects in this illuminating, delightfully illustrated volume that reaffirms the artist's stature as it traces the fine line he toes between reality and illusion. (Dec.)