There are always those who are criminals by instinct, who must be kept from society and from injuring others, because their minds are incapable of reformation, their wills too weak to keep them from lives of crime.
 Franklin D. Roosevelt, Looking Forward (1933). copy citation

Context

“We have assumed that the horrors of prison life, that the stigma which society brands upon every prisoner, were forcing him through sheer terror into the path of virtue on his release. That is not true. We must always have prisons. There are always those who are criminals by instinct, who must be kept from society and from injuring others, because their minds are incapable of reformation, their wills too weak to keep them from lives of crime. These must be rearrested and rearrested and rearrested. Our police records are full of criminal biographies of those who have spent, since they reached adolescence, far more time in jail than out of it.” source