The Nation article gives the full background of Smith, the supposed discovery the Clementine letter, and the history of the debate. Here are some snippets:
To prove that Smith invented nothing, Stroumsa has published a fascinating collection of primary sources: Smith's correspondence with a lifelong friend, the twentieth century's greatest Jewish scholar, Gershom Scholem. Smith, an adventurer in life as well as in scholarship, went to Jerusalem in 1940 on a Sheldon Traveling Fellowship awarded him by the Harvard Divinity School. Caught in Palestine by World War II, he spent four years there. At the Hebrew University--the pre-eminent German university in the world in those days, thanks to its faculty of erudite, brilliant refugees--Smith studied classics with Moshe Schwabe and Hans Lewy and Jewish mysticism with Scholem. He helped translate Scholem's first great book on the Kabbala, Major Trends in Jewish Mysticism, and translated an ancient Jewish mystical text under Scholem's supervision. More remarkably, Smith wrote a doctoral dissertation, in Hebrew, on Tannaitic (early rabbinical) parallels to the Gospels and became the Hebrew University's first Christian PhD. Returning to the United States in 1945, he began a career in the Episcopalian ministry, then moved back into scholarship and became, eventually, a professor of ancient history at Columbia University, where he taught until 1990. From 1945 until Scholem's death in 1982, the two men corresponded regularly. Their letters, which Stroumsa and associates have edited, open a new window on Smith's career, the scholarly world in which Smith flourished and the Secret Mark.
For Stroumsa, the documents make one point clear beyond doubt: Smith could not have forged Clement's letter or Secret Mark. For Smith's letters show him discussing the material with Scholem, over time, in ways that clearly reflect a process of discovery and reflection. From the start, he was sure he had a new work of Clement's on his hands. In August 1959, Smith wrote to Scholem that "the material by Clement of Alexandria which I found at Mar Saba last year is turning out to be of great importance, and as soon as I get all minor nuisances off my hands I must work hard at it." Later that year he went into more detail, noting that the letter "contains some amazing information about the Carpocratians and the Gospel according to Mark." By early 1961 he was working up the materials that eventually went into his two books.
But the more radical conclusions took time to emerge. Not until October 1962 did Smith tell Scholem that "I am really beginning to think Carpocrates and the sort of things he represented (and especially the ascent through the heavens) were far closer to Jesus than has ever been supposed." If Smith really forged Clement's letter, then he also must have spent years deliberately deceiving one of the few scholars he deeply respected. Yet he showed remarkable equanimity when his efforts proved partly unsuccessful. When Smith's scholarly book on Secret Mark appeared, Scholem accepted the letter as Clementine. But though he appreciated Smith's evidence about the magical side of early Christianity as "very good and convincing as far as it pertains to the tradition of the original church," he also found himself "not sure whether the story can be truly taken as historical evidence about Jesus himself." Smith, in his reply, showed only gratitude for his friend's detailed critical response: "Your letter pleased me very much and I thank you most sincerely for writing me at such length about my book.... As to Jesus, I should perhaps have emphasized more strongly that all accounts of his teaching and practice are conjectural, and I claim to my own conjectures only that they fit the reports as well as any and better than most." This is the tone of a colleague in inquiry, not a foiled forger.
On the personality of a forger: one of wit, in Smith's case, searing wit:
Smith's letters, moreover, show that he possessed at least a couple of the qualities of the successful forger, and in spades. Unlike British and European scholars, most Americans receive relatively little training in composing ancient Greek and Latin. We have as yet produced no counterpart to "Herodotus at the Zoo," a brilliant homage to the Greek traveler and historian Herodotus composed by the legendary expert on Athenian pottery, J.D. Beazley. Smith, however, was a gifted and assured practitioner of prose composition--he wrote his dissertation and his first letters to Scholem in Hebrew. Most philologists, as is well known, have little sense of humor--something every forger needs. But Smith's letters are consistently witty, at others' expense and his own. In 1960, when he decided to turn down an offer from Cornell and stay at Columbia, he explained his decision to Scholem with a characteristically neat paradox: "If I buried myself in Ithaca I should never forgive myself for having sacrificed the theater and the opera and the galleries, but so long as I stay here I can indefinitely put off going to them, and feel happy and virtuous about it." A really good academic novelist--someone like Allegra Goodman, who wove the dismal straw of contemporary laboratory life into fictional gold in Intuition--could find rich material here for a tale of how the ironist of Providence and Morningside Heights became the forger of Mar Saba.
The newly published letters, though they suggest and support this reading, don't quite clinch the case: indeed, they suggest that Smith, writing years later, may have remembered as conversations exchanges that actually took place on paper. I believe that Smith really found his letter, and that Scholem gave him the framework into which he inserted it. But that's just what I think. Many will disagree. This time, the professor is the Cheshire cat. He smiles and is gone.
The article is ultimately a bit long, but worth the reading. Given my position at Columbia and the former Morton Smith Fellow, I will keep my opinions about it to myself.