What’s notable about these inmates isn’t just that they’ve fallen out of the education system. In many cases, “zero-tolerance” policies in schools led them down a path that culminated in prison. In what is sometimes called the “school-to-prison” pipeline, administrators are ordered to suspend students for infractions as minor as dress-code violations and cellphone use. These approaches are a variation on the “broken-windows” policing that took off around the 1980s, especially under the former President Ronald Reagan and, in New York City, the former Mayor Rudolf Giuliani and Police Commissioner William Bratton. Such punishments—detention, expulsion, and increasingly, arrest—can set up nearly insurmountable barriers that eventually serve to exclude young people from meaningful participation in society (felony disenfranchisement, minimal job training) and stifle their development, making them “hard” and more likely to commit worse crimes upon release.

What this means is that a disproportionate number of poor people spend their 20s and 30s not in higher-education institutions, but in prison; one in 10 black males in their 30s is in prison on any given day, according to The Sentencing Project. This suggests that, for these people caught in the incarceration net, the prison—and not the university—is the rite of passage into adulthood.

Yet prison doesn’t necessarily have to end these young people’s educations. In some cases, it can even mark the beginning, as I have witnessed during my eight years of teaching college-level philosophy courses in prisons in Texas, New York, and Connecticut. One particular encounter has stayed with me through the years. After a lecture and discussion on Descartes’ Meditations, one of the students, a man named Roy D., lingered. He was a truck driver before he ended up in the Texas prison at which I taught, where public records show he will remain for the rest of his life. After the session, he adjusted his cheap plastic glasses, held together by a piece of tape, and said, “I’ve never felt so free as when I’m in this class.”

Malcolm X, it seems, had a similar experience with education. In his autobiography, he wrote of his own years behind bars. After being frustrated that he could not “express what [he] wanted to convey in letters that [he] wrote,” Malcolm X picked up a dictionary and began to copy every single word. “Months passed without my even thinking about being imprisoned. In fact, up to then, I never had been so truly free in my life.”

Investment in rehabilitative programs like drug counseling or educational programming at prisons has declined in favor of techniques of deterrence such as surveillance, isolation, and punitive control. A 2011 report by the Institute for Higher Education Policy reported that only 6 percent of the prison population was enrolled in an education program during the 2009–10 academic year.