Challenging the accepted notions about prisons, Dilulio argues that, far from being traps for society's refuse, they must and can be made safely humane. He shows that the key to better prisons is a highly disciplined "constitutional government" employing prison managers who are strong enough to control the inmates yet obliged to control themselves. The book illustrates how the use of such a governing system can provide order, encourage civilized behaviour, and enforce punishment that is just, as well as merciful.