Grayling (The Choice of Hercules
) winnows a universe of ideas, ideologies, and philosophies into “a personal dictionary” for understanding the new century. With topics chosen according to the author’s interests and for their “intrinsic significance,” the alphabetically organized list leaps from the antediluvian—“Afterlife”; “War”—to the contemporary—“Artificial Intelligence”; “Internet.” Each self-standing entry includes a concise introduction intended as a starting point for further investigation by the reader, but the author eschews references and includes only a brief bibliography. While some readers will question the inclusion or omission of specific concepts—why “Vegetarianism” but not global warming?—the list is largely conventional if abstract and rather coolly academic. Grayling’s dictionary will appeal to readers looking for a perspective of the 21st century’s big ideas as seen from the ivory tower. (Apr.)