Theatrical release set for the day Pope Benedict XVI visits a Holocaust-survivor rabbi at his Upper East Side synagogue, Constantine’s Sword is honest and earnest. But while the public should see it for the laudable scholarly approach to a seldom aired controversial topic, Oren Jacoby’s latest documentary illustrates the rut the burgeoning genre has fallen into.

Gone is the dramatized or minimally narrated format, in favor of parades of archival footage, re-creations, voiceovers and after-the-fact interviews, all delightfully parodied in Luis Pepe and Keith Fulton’s overlooked Brothers of the Head. No longer pretending objectivity, and lecturing instead of showing, the advocacy documentary surge has spun off a kind of subspecies, the narrator as participant, in part subject, detailing his personal arrival at epiphany.

That route is a corollary of the source, ex-priest, co-writer and –producer James Carroll’s book of the same title, as the onscreen author serves as cicerone through military academies and libraries, basilicas and cloisters, ghettos and concentration camps, archaeological digs and cemeteries, linked by the non-fiction fad of his voiced musings from a moving vehicle. The anti-Vietnam War activist when he was Boston University Chaplain is candidly confessional in baring his twofold soul-search, for reconciliation with the truth of his heavenly -- as opposed to institutional -- Father, and of his biological one, who rose from “the poorest of Irish poor” to immense power in the Pentagon. A concluding visit to Arlington National Cemetery, emphasizing Hebrew characters on gravestones, would indicate failure in that second quest, while the first leads to the roots of anti-Semitism and to the current inroads of America’s Religious Right (even as facile end-titles detail yet another scandalous fall from grace).

Those closing titles accompanied by Aaron Neville’s quavering “With God on Our Side” hark back to the opening (and recurring) U.S. Air Force Academy, where Carroll early dreamed of enrolling and where muscular Christianity is proselytizing and flouting First Amendment separation of church and state. A chaplain fired for objecting and a Jewish cadet and his cadet wife and alumnus father facing insensitivity, harassment and coercion, are set against rock services at cadet-attended New Life Church and toothy confidence from the National Council of Evangelicals.

Thought does not entirely leave the Colorado campus but location shifts to church-and-state in Rome and German cities and Rhine towns. On the path to conquest and consolidation, Constantine I the Great crossed Tiber’s Milvian Bridge in 312 and, says legend, beheld in the sky the fateful cross flaming and proclaiming, In hoc signo vinces, “By this sign thou shalt conquer.” What follows onscreen concerns the emperor-to-be’s motivations and sincerity, his linking the henceforth symbol of the Savior -- early adherents preferred the life-related fish -- with the bloody sword of domination, and his own character as shown in the brutal murders of wife Fausta and Crispus, his son by a previous marriage.

Machiavellian or converted, the Emperor’s personality and policies--not brought out is that Christianity was legalized but not, as often believed, made official -- give way to consideration of his mother, the Saint Helena who collected relics the way Carroll’s “mother collected antiques.” Relics have power: German Trier’s cathedral houses the seldom-exhibited Holy Coat of Jesus, the concept of which derives from Psalm 22 and thus predates the Christian era but which is perpetuated in Hollywood hokum like The Robe and has been manipulated as incitement against “Christ-killers.” Thus the Jews massacred by Crusaders before disembarking to reconquer Jerusalem, suffering hellfire in three-dimensionalized Bosch paintings; dispossessed, disenfranchised and ghettoized mere blocks from Vatican City, ignored by a Papacy covering its back with Hitler, demonized in The Passion of the Christ, and viewed as convert fodder by a Christian Right that supports the President’s modern “crusade, this war on terrorism.”

With Dustin Hoffman as caustic Lenny flaunting the Freudian gallows humor of the victim, the film widens its indictment of those ancient and current campaigns that would appropriate Divine Will to their whatever holy cause, Melville’s “minister of Christ . . . receiving his stipend from wars.” Such oxymoronic juxtaposition is, indeed, a prime mover in now-married-with-children Carroll’s decision to doff the cloth. Time is given to compassionate men and women of the clergy, even of politics, but the documentary, and the world scene, is overwhelmingly of institutions and their faithful who have lost the path of brotherhood to 1 John’s “God is love.”

Carroll’s journey would seem at an impasse, his father and so many others dead and buried and religious-like fanaticism of many stripes marching ever more aggressively. The message is clear.

But the medium is muddled. Almost eight hundred pages, the book is one thing, the authorial voice with leisure to walk the reader through two thousand years of Western history, culture and thought, while simultaneously inviting companionship on an inward exploration of conscience. Individual sincerity and societal urgency are apparent on the screen, where the author’s person and voice unify but still do not add up to a cinematic gauge for selectivity. The result goes everywhere, and thus not specifically enough anywhere for ninety-five visual minutes to contain it all. There is too much food for thought, the separate aspects of which each begs for specific treatment of the sort accorded onstage by Hochhuth in The Deputy. 

(Released by Storyville Films; not rated by MPAA.)