I normally don’t use this space to comment on movies, but I want to make an exception in the case of “12 Years a Slave,” which is the most powerful portrayal of American slavery that I’ve ever seen in film.

To start with, it’s just a really compelling narrative about a man who spent his life as a free man in New York, built up a career as a violinist, had a wife and two children, and then was kidnapped and sold into slavery in Louisiana in 1841.

He remained a slave until 1853. It’s based on the real-life memoir of Solomon Northrup, so it’s not a spoiler to say he eventually regained his freedom and lived to tell about his ordeal.

The fact that Solomon had known freedom his whole life provides him with a unique perspective once he’s forced into slavery. In a way, it’s a reverse version of Plato’s allegory of the cave.

In Plato’s famous analogy, people grow up chained and facing a wall and begin to assume the shadows they see being projected from the fire behind them represent reality.

But what if somebody reached adulthood living in the real world, and then was sent into the cave to stare at shadows? What would that do to his perception of reality and sense of identity?

I should caution that the film isn’t for the faint of heart, as it contains a lot of graphic violence, including sexual assault. But though graphic, the violence serves an important purpose – to capture the raw brutality of the institution of slavery.

A lot of people have remarked that the film is a rebuke to “Gone With the Wind,” which is often criticized for papering over the injustice of slavery and portraying Southern masters in an overly sympathetic way. But it is more than that.

In attempting to take a grittier approach to the topic of slavery, the filmmakers could have fallen into the trap of embracing another cliché in which they turned every master into some sort of sadistic warden.

Instead, they took a more nuanced approach, showing the type of rationalizations and compartmentalization that made even decent-seeming people so casually perpetuate an unthinkable evil.

For instance, even the more benevolent master in the movie is ultimately willing to separate a female slave from her children, because “it couldn’t be avoided.”

His wife, who initially seems to show empathy for the woman’s tragedy, calmly tells her to get some food so she’ll forget about her kids.

This is a chilling phenomenon, and something that Frederick Douglass described in his own memoir when he explained how his master’s wife, who had initially started teaching him to read, turned against him after being rebuked by her husband.

“Slavery proved as injurious to her as it did to me,” Douglass wrote. “When I went there, she was a pious, warm, and tender-hearted woman. There was no sorrow or suffering for which she had not a tear.

"She had bread for the hungry, clothes for the naked, and comfort for every mourner that came within her reach. Slavery soon proved its ability to divest her of these heavenly qualities.

"Under its influence, the tender heart became stone, and the lamblike disposition gave way to one of tiger-like fierceness.”

It’s always been gut-wrenching to consider that a nation that has done more than any other in history to advance the cause of human liberty could have allowed such a grave injustice to persist for so long within its own borders.

I’ve remarked on several occasions in this space that American slavery did more damage than anything else to the cause of limited government and state sovereignty.

And whether we like to accept it or not, the legacy of slavery has a profound effect on race relations to this day. This movie, with its honest and haunting portrayal of the institution, is long overdue.