Voltaire once famously called Shakespeare a “drunken savage” who created a “crass and barbarous” play. He was referring to “Hamlet,” but he might have had “The Merchant of Venice” (1597) in mind. The so-called “comedy” of a tantrum-throwing Jewish moneylender, Shylock, who demands a pound of flesh from a Gentile borrower, still disturbs audiences, as it did in 1600 when the play was first published with a lengthy title excoriating the “extreame crueltie of Shylocke the Iewe.” Sixty years after Auschwitz, can Shylock’s punishment for his “extreame crueltie,” forced conversion to Christianity, be considered jolly entertainment? A new book by Kenneth Gross, an English professor at the University of Rochester, “Shylock Is Shakespeare” (University of Chicago, 202 pages, $22.50) aims to redeem Shylock as a charismatic character, on the grounds that he speaks with the voice of Shakespeare himself.

Mr. Gross is attempting more than a restating of what the critic William Hazlitt wrote in the early 19th century, that Shylock is “another instance of Shakespear’s powers of identifying himself with the thoughts of men.” Hazlitt praised Shylock for having “more ideas than any other person” in the play, and Mr. Gross’s book is a concept-stuffed feat of Nabokovian ratiocination. Belying the simple equation in its title, “Shylock Is Shakespeare” suggests that Shylock’s “frightening charisma” derives from the fact that his “hatred is a mirror of Christian hatred … he reveals himself as a hallucination of the Christians.”

Whatever its hallucinatory force may be, “Merchant of Venice” cannot be rated among Shakespeare’s best comedies. It’s better than “The Comedy of Errors” — most of the plays are — but cannot compare with masterpieces like “Twelfth Night” or “As You Like It.” Yet Mr. Gross’s linguistically sensitive dissection of the flawed play reminds us that powerful metaphors are what keep it alive today. These metaphors are deeply imbued with the conflict between Judaism and Christianity, which has not hindered “original” stage directors from betraying its essence. Peter Sellars was one; his 1994 staging at Chicago’s Goodman Theatre transposed the action to Venice Beach, Calif., and cast all the play’s Jewish characters with African-American actors. An equally unfaithful 2005 production in Cork, Ireland, cast the play’s Jewish roles with Polish actors, as a comment on Ireland’s recent “large influx of Polish immigrants.” And the “Maori Merchant of Venice,” a 2002 film from New Zealand with a local cast was intended as a reflection of “racial and religious tensions felt by the Maori” under European colonization.

In contrast to these vagaries, Mr. Gross returns Shylock to Venice, where he posits a walk with the moneylender, because he amusingly “cannot imagine Shylock in a gondola.” In his “reimagining” of Shylock, Mr. Gross offers a fan letter written by Shakespeare to Philip Roth — another of Mr. Gross’s academic specialties — in tribute to Roth’s 1993 novel “Operation Shylock: A Confession.” Other reimaginings liken works by Kafka, F. Scott Fitzgerald, and Jorge Luis Borges to certain aspects of the play. Citing a scene in which the romantic heroine Portia requires her suitors to choose from three caskets of gold, silver, and lead, Mr. Gross asks his readers to “imagine a dance choreographed by George Balanchine entitled ‘Three Caskets,’ a pendant to … his ‘Jewels,’ which has a dance apiece for diamonds, rubies, and emeralds.” This notion is somewhat spoiled by the author’s apparent unawareness that Balanchine’s “Jewels” is indeed partly set to Fauré’s music for “Shylock,” an 1889 French play based on “Merchant.”

Elsewhere, Mr. Gross expresses sanguine — and perhaps overstated — hopes for the future of Shylock onstage. He suggests that the late Zero Mostel would have been an ideal Shylock, as a “more ferocious version of Mostel’s Max Bialystok in Mel Brook’s 1968 film ‘The Producers.'” Yet the roles of Shylock and Bialystok can be incompatible, as they were for the stellar British thespian Henry Goodman, an award-winning Shylock on the London stage who was summarily fired by Mel Brooks just before he was to take over the role of Max Bialystok in Broadway’s musical version of “The Producers.”

Shylock’s future legacy as an unsympathetic, indeed anti-Semitic comic villain, may rest with today’s Jewish comedians who, unlike Borscht Belt comedians of yore, do not try to attract an audience’s sympathy or pity. Like Shylock, today’s TV comedians like Larry David and Sarah Silverman vehemently demand our disrespect, presenting purposefully unappealing and sometimes vindictively sociopathic Jewish characters for public amusement. Larry David’s HBO series “Curb Your Enthusiasm” features an episode in which a kidney for transplant is coveted in a manner not far from Shylock’s wangling for a “pound of flesh.” In another episode, Mr. David was cast as Max Bialystok in the musical “The Producers”; can Larry David as Shylock, or “Curb Your Anti-Semitism” be far away? According to the old canard, if Shakespeare were alive today, he’d be a head writer on a TV sitcom. Perhaps not, but Shylock may have a bright future, nonetheless, as the star of an HBO comedy series.

Mr. Ivry last wrote for these pages on Woody Guthrie.