The digital era is beset by distraction, and it feels like things are only getting worse. At times like these, the distant past beckons as a golden age of attention. We fantasise about escaping our screens. We dream of recapturing the quiet of a world with less noise. We imagine retreating into solitude and singlemindedness, almost like latter-day monks.

But although we think of early monks as master concentrators, a life of mindfulness did not, in fact, come to them easily. As historian Jamie Kreiner demonstrates in The Wandering Mind, their attempts to stretch the mind out to God-to continuously contemplate the divine order and its ethical requirements-were all-consuming, and their battles against distraction were never-ending. Delving into the experiences of early Christian monks living in the Middle East, around the Mediterranean, and throughout Europe from 300 to 900 CE, Kreiner shows that these men and women were obsessed with distraction in ways that seem remarkably modern. At the same time, she suggests that our own obsession is remarkably medieval. Ancient Greek and Roman intellectuals had sometimes complained about distraction, but it was early Christian monks who waged an all-out war against it. The stakes could not have been higher: they saw distraction as a matter of life and death.

Even though the world today is vastly different from the world of the early Middle Ages, we can still learn something about our own distractedness by looking closely at monks' strenuous efforts to concentrate. Drawing on a trove of sources that the monks left behind, Kreiner reconstructs the techniques they devised in their lifelong quest to master their minds-from regimented work schedules and elaborative metacognitive exercises to physical regimens for hygiene, sleep, sex and diet. She captures the fleeting moments of pure attentiveness that some monks managed to grasp, and the many times when monks struggled and failed and went back to the drawing board. Blending history and psychology, The Wandering Mind is a witty, illuminating account of human fallibility and ingenuity that bridges a distant era and our own.