At a play with a title like “New Jerusalem: The Interrogation of Baruch de Spinoza at Talmud Torah Congregation: Amsterdam, July 27, 1656,” the last thing you’d expect is Borscht Belt humor. Wisecracks at the trial of the brilliant-but-persecuted philosopher as he teeters on the brink of excommunication?

Yep — and there’s plenty more shtick where that came from. In Walter Bobbie’s blithely tone-deaf production of David Ives’s play, now at the Classic Stage Company, loudmouthed comic outbursts punctuate stretches of anxious courtroom drama. The result is an odd mishmash, as though someone had tried to jazz up “The Crucible” by adding comic relief.

We first meet young Spinoza (Jeremy Strong) staring at the sunrise, holding forth about the splendor of nature between hacking coughs from his weak lungs. Intellectually, he’s an eager beaver; his ideas burst forth in impulsive floods, and when he comes to an unsolved problem, he endearingly notes that he “hasn’t worked that one out yet.” Of late, however, those unchecked bursts of philosophy have fallen on the wrong ears. Spinoza is summoned to the synagogue for a hearing.

Inside the synagogue, the vibe is pure Rembrandt: dark wood, pale faces emerging from dark collars and dark recesses. A massive wooden table dominates the center of the room, and around this behemoth the actors must squeeze in their scenes. Not surprisingly, Mr. Bobbie’s staging — which forces them to circumnavigate the table — is frequently distracting. But he makes it even more so by placing the audience on three sides and having the actors play to the crowd as if it were the actual congregation, assembled to witness the trial of one of its own. Apart from feeling corny and amateurish, the “you are the congregation” conceit never takes a firm hold, but is invoked periodically, as if to ramp up the tension.

But the stakes were never high to begin with, since Mr. Ives’s slack play never locates the dramatic tension in Spinoza’s situation. Apparently believing that Spinoza’s long philosophical speeches are hard work for their audience, Messrs. Ives and Bobbie administer frequent spoonfuls of sugar to help the medicine go down. But these doses of sugar — jokes, easygoing banter at the tribunal table, the meddling of a busybody half-sister — effectively take the menace out of the air.

An inquisition atmosphere never develops in this namby-pamby courtroom. People interrupt one another at will, Spinoza treats the whole thing as a lark, and everyone is asked their opinion, as if a religious tribunal were essentially one big rap session. At one point, Spinoza smooches his Christian girlfriend on the sacred turf of the synagogue and no one much minds. Whatever this is, it isn’t 1656.

Still, if you can get past a series of fussy, melodramatic subplots involving Spinoza’s love interest, his false friend, his half-sister, and his rabbi and father figure (the excellent Richard Easton), there is something remarkable about “New Jerusalem”: those long monologues and dialectics drawn from Spinoza’s writings on religion. These passages are fascinating and perspicacious, and as Spinoza, Mr. Strong delivers them with clarity and verve.

But in the end, Spinoza’s thoughtful analysis of religion feels out of place alongside the mawkish material that pads out “New Jerusalem.” The broad jokes (“There’s no Jewish dogma, only bickering,” goes one) may be intended as throwaways, but they effectively drain the tension out of Spinoza’s predicament. Mr. Ives wants to make riveting theater about a man on trial for his ideas — while scattering yuk-yuk jokes along the way. As Spinoza knew only too well, you can’t have it both ways.

Until February 3 (136 E. 13th St., between Third and Fourth avenues, 212-352-3101).