“The Barnes Foundation is the only sane place in America to see art.” So declared no less an authority than Henri Matisse, and if his praise of the Lower Merion Township, Pennsylvania, institution reflected personal bias – he was friendly with its founder, Dr. Albert C. Barnes, who shrewdly collected several of the French painter’s most celebrated works – he can be forgiven.

You don’t have to be an art enthusiast to appreciate The Art of the Steal, Don Argott’s remarkable account of, as one observer puts it, a theft committed in broad daylight. The story he tells is heartbreaking and infuriating, an impressively detailed illustration of how opportunistic politicians and well-connected profiteers acted in concert to despoil an American treasure – and, in doing so, flouted the wishes of the man who created it.

A little history: Barnes, an early 20th century collector whose paintings – by the likes of Renoir, Monet and Picasso, among many others – were scorned by the art establishment of his day, responded to the snub by displaying them at his Foundation in a picturesque Philadelphia suburb.

An avowed enemy of socialites who treated art as glorified wallpaper, Barnes made his collection available at first only to students and, on occasion, working-class visitors who might not otherwise have access to the works of the masters. In his will, he insisted the paintings, now accessible to the public, never be removed from his modest mansion, and ceded control of them to Lincoln University, a small, predominantly black school just outside the city.

That the very people Barnes despised would ultimately appropriate his paintings, now valued at more than $25 billion, is made clear from the documentary’s opening scene. Argott starts at the bitter end, then explains how we got there. Along the way, he uses archival footage of Barnes, who died in 1951, and interviews with all the principal players, to explain the inner-workings of a complicated tragedy. A veteran cinematographer, his visual presentation is stylish, but here story is king.

And what a story it is. There are many villains in Art of the Steal. With his smirk and apparently self-serving agenda, Richard Glanton, the first Foundation caretaker to defy Barnes by sending his paintings on a for-profit world tour, looks and acts the part. Yet his betrayal merely laid the groundwork for greater indignities to come.

Bad management and shortsighted greed led the Foundation into financial straits, and its Lincoln University guardians, desperate for funding to refurbish a campus in decline, relinquished control in exchange for a mere $40 million – or, to put it in perspective, less than the cost of a single painting.

As one critic notes, the city of Philadelphia, aided by a powerful lobby of so-called altruists, pursued control of the Barnes collection the way Ahab chased the white whale. With it, they swiftly declared its Lower Merion home inadequate and made plans to move the works to a major new museum opening in 2012 – one that would, as the mayor saw it, "put the city on the map."

Did Philadelphia need to steal the Barnes from a suburb four miles away, over the town’s vigorous objections, to be considered a big-league city? Certainly not. Should public demand for easier access to fine art transcend the dying wishes of the man who bought and preserved it for educational purposes rather than adding it to the treasure of a prestige-seeking major museum? It’s a difficult question, and some would say yes. Argott’s sympathies seem to lie elsewhere, but to his credit, he affords ample screen time to all parties and leaves the decision to his audience.

If the subject sounds too arcane to leave viewers outraged, don’t be deceived. The Art of the Steal is an important film, and not simply because it affirms the cynical adage that you can’t fight city hall. The lesson here is more chilling – that if you have something worth stealing, no contract, however sacrosanct, can protect it. Want your legacy to be honored after you’ve gone? Better try living forever.

Art of the Steal plays at the Roxie Theater this Thursday. For tickets, click here. It opens around the Bay Area on March 12.