I suppose there is a sense in which ''The Sexual Life of Catherine M.'' might be perceived as an erotic breakthrough, a daring leap into a place where no woman -- or man, for that matter -- has gone before. But that immediately raises the question: Is this really a place worth getting to?

''The Sexual Life of Catherine M.'' is as ponderous as it is heavy-breathing, which is saying a lot. As the author pursues ''fornicatory communion'' as frequently and publicly as possible, and as she approaches her mission ''with the application of a musician composing a fugue,'' she totes her critical acumen to places where it is not entirely useful. Her book lurches to and fro between the frankly obscene and the absurdly high-minded.