By Robert A. Ferguson, Harvard University Press, 337 pages

The United States spends more than $80 billion a year on corrections. In the last three decades of the twentieth century, incarceration rates rose 500 percent. One in nine state government employees now works in corrections. The recidivism rate across the nation is more than 67 percent. Our nation boasts more than 10,000 people in solitary confinement. One in 20 prisoners reports being raped. These statistics may be startling to some, but as Columbia Law Professor Robert Ferguson points out in his poignant new book, “Inferno: An Anatomy of American Punishment,” it is hard to grasp the meaning of such numbers. “Actually knowing what inmates endure presents a serious complication with no simple solution.” He asks whether we can really comprehend punishment at this level.