The intellectual legacy of Platonic philosophy takes on entertaining new life in this sophisticated and very funny fable by the protean British author (The Life of Thomas More, 1998, etc.). Prefatory quotations from various fictional scholarly sources inform us that the human race has reached the year a.d. 3700, despite the quenching of the world’s “light” (due to nuclear catastrophe?) centuries ago, followed by a period of enlightenment (—The Age of Witspell”). The setting is London, where a —great orator” named Plato dispenses wisdom, eons after his namesake flourished in Athens (during “The Age of Orpheus”). In 55 brief chapters, Ackroyd juxtaposes brief conversations between Plato and his (feminine) soul and with his several admiring disciples (who discuss him, in separate chapters), with the great man’s “exequies” on evidence of earlier civilizations’ mistakes (an exhumed copy of Poe’s stories is believed to be “the unique record of a lost race” sunk in paranoia and depression; surviving fragmentary texts reveal the existence of a prophetic black singer named George Eliot and “a clown or buffoon who was billed as Sigmund Freud”), and excerpts from Plato’s “glossary” of antiquities (“rock music” is presumed to denote “the sound of old stones”). Fortunately, this slim book doesn’t settle for elegant gags. Plato’s fascination with the alien cultures of the past inspires him to undertake a “Journey to the Underworld,” during which he discovers the parallel existence (beneath Witspell) of ‘’ Mouldwarp” (our own civilization, supposedly ended when “the light” disappeared). The result is his trial, ostensibly for corrupting the young; in reality, for having introduced uncertainty into a world smugly convinced that it knows itself, and thus knows all. A strikingly imaginative and provocative cautionary tale that makes superb use of Ackroyd’s formidable erudition. One of his most satisfying books.