The idea that prisoners should be treated humanely was discussed by Enlightenment Era aristocrats, "but the idea that they are people who are peers is new," says Yale Law professor Judith Resnik.

"As Democratic norms turned us all into equal citizens, equal persons in a jurisdiction, the question of government's relationships in courts, policing, schools and prisons changed over the last hundred years," says Resnik, author of Impermissible Punishments: How Prison Became a Problem for Democracy.

In this episode of the Modern Law Library, Resnik walks host Lee Rawles through centuries of discussion about how punishments are deemed to be permissible, from a trial about whipping prisoners in Arkansas to the League of Nations' effort to develop minimum standards of treatment in prisons worldwide.

"People who run prisons have a very challenging time, and there's a body of data growing that people who work in prisons, like people who live in them, have higher stress, heart attacks, blood pressure, suicide rates," Resnik tells Rawles. "These are terrible environments of concrete and metal and noise and often dirt and violence. In the United States, many people who are in detention have had mental health issues and behavioral issues of significant kinds. And when you take people with limited training, often with staffs that are too thin, interacting with overcrowded facilities of metal and concrete, with limited resources, you end up generating scary places for everybody.

"So one of the kind of puzzles, if you step back, is how a thing called corrections, that promises safety, has generated institutions that are deeply unsafe for the people who live and work in them."