In ''Conversations with Professor Y'' he set out to restore his reputation as an innovative literary stylist. The book appears here in English for the first time, alongside the French text, in a solid translation. Professor Y is a fictional foil for the author's digs at formal literature, and much of ''Conversations'' is hilarious. Celine is self-mocking as he tries to get his name back into circulation. He compares an eager genius to the new Big Bubbly soap product, is adamant in his revulsion at the ascendancy of ideas over emotion and is passionate in his desire to capture the immediacy of conversation on the page. ''The emotion of spoken language through the written form! Just reflect on that a bit, dear Professor Y! get your noodle in gear!'' Poor Professor Y! This dull academician (whose most intelligent comment is ''Why, holy moly! you're afloat in dialectics!'') is led on a dizzying tour of Paris, overwhelmed by a crazed author who claims he's on the brink of a revelation just when the professor expresses a need to find a bathroom. ''Conversations''is essential for Celine fans, and a good, if tame, introduction for the uninitiated.