Complex sentence: Hook's review was positive, describing the book's publication as "an intellectual event of the first order", and writing that the book opened a "new era in Marxist criticism" and that no one concerned with Marxism could afford to ignore it.
Split into simpler sentences: Hook's review was positive, describing the book's publication as "an intellectual event of the first order". Hook wrote that the book opened a "new era in Marxist criticism" and that no one concerned with Marxism could afford to ignore it.