The Love of Impermanent Things: A Threshold Ecology

At midlife, Mary Rose O’Reilley writes, we are called to an “archaeology of memory”—turning over a potsherd here, a fragment there—to assemble something whole out of the messiness of experience. Excavating her own life, she traces the middle-class Irish American background that shaped her, with its mix of antic humor, terror, and mysticism, and finds meaning in the seemingly smallest, most transient encounters.

But O’Reilley’s purpose is less to recount these moments than it is to find the l...