Dazzling--which is no more than anyone by now expects of William Gass. Where else is such mischievous articulation, mastery of the individual sentence, and deep imaginative fling applied to the essay? Gass himself admits that these are ""experiments with the interplay of genres, attempting both demonstration and display, skids of tone and decorum associated formerly with silent films, jazz bands, and the slide trombone."" Whether he's writing about Malcolm Lowry, Sartre, suicide, Colette, or Freud, Gass is the one you watch, the man up on the highwire. Quoting slivers is risky, like tearing a sheet of newspaper that's not first well folded, but trust that there is language here that demonstrates an antic intelligence rarely encountered in our literary life. Gass' discussion of Gertrude Stein may be the best ever uttered; it unkinks the randomness of Stein's work and then lets it snap back into mystery, in the meantime having persuaded you that the woman, amidst the non sequiturs and repetitions, was actually telling us a powerful sexual story. And Gass' devastation of Sartre's intellectual fickleness is as sedulous and damaging as a giant termite. All said, however, this collection still seems lighter than Gass' earlier, enormously influential Fiction and the Figures of Life. A rhythm to the pieces starts to be predictable: Gass gets going with a remarkable biographical perfusion, moves into the literary--usually formalist--significance, then ends weakly. And Gass the professional philosopher shows up more boldly: diagrams and fussed-over designations: ""polytokenal,"" ""polytype,"" ""metatextual."" Nonetheless Gass is hard to resist; before you realize it, the sumptuousness of his language has pillowed you exactly where he wants you. The reader, thrilled by the ingenuity of speech, follows, eventually assents--but does he ever think? This numbing of thought by speech is essentially fiction's tactic. Is it criticism's? Gass' hybrid--the fictive essay--raises the question with maddening elegance.