The critical praise for “12 Years a Slave” has hit with all the fervor of a revival preacher, the film’s significance so heavily underscored as to be almost intimidating. Now, I’m not suggesting this horrific piece of our history isn’t challenging material, but director Steve McQueen and screenwriter John Ridley use the full measure of filmmaking’s potential to gripping effect. The actors, fearless and fierce, do exceptional work to convert the abstract idea of slavery into concrete shape and form. For those still conflicted about seeing it, here are seven more reasons: Chiwetel Ejiofor, as the freeman kidnapped, shipped south and sold into slavery, reveals the very soul of bondage, from the weight of the chains to the unquenchable drive to shed them. Lupita Nyong’o as Patsey, raped by her master, despised by her mistress, beaten without mercy, makes despair defiant. Michael Fassbender and Sarah Paulson as sadistic slave owners expose the blackened heart of the inhumane. Benedict Cumberbatch as the patrician plantation owner lays bare the price of complacency. Brad Pitt as a carpenter shows the effect of a moral man’s single decent act. And Solomon Northup, whose story this is, reminds of the power in truth and the importance of telling it.