It is no meager feat to defend a man whose own mother could not bring herself to forgive his sins—but this is the task to which Frederic Raphael sets himself in A Jew Among Romans, his apologia for the classical Jewish historian and arch-turncoat Titus Flavius Josephus.

Little is known about the biography of Josephus, born Joseph ben Mattathias in 37 c.e., other than his claim to priestly and royal lineage. The historical record—largely his own hand—first encounters him as leader of the Jewish rebels of first century Judaea in their Great Revolt against Rome. He offers himself as a pious Jew who is also a pragmatist, resisting the Empire’s petty impositions but equally frustrated by the Zealots who agitate for all-out war. Josephus is dragged into direct conflict with Rome and tasked in 67 c.e. with defending Jotapata, modern-day Yodfat, against Vespasian’s men.

When the hilltop fortress falls, Josephus escapes the suicide pact struck by his comrades and surrenders to the Romans, becoming first a prisoner and later, by dint of his supposed prophetic abilities, a counselor to Titus. He takes the Empire of its coin, even adopting the Romanized name Titus Flavius Josephus, and begins to document the ensuing sack of Jerusalem and the destruction of the Second Temple from his handsome sinecure as defeated Jewish rebel turned Roman stenographer. His Jewish War rails against the fanatic garrisons who, as he saw it, provoked the suppression of the Jewish polity in Judaea before dying by their own hand at Masada.

Josephus provided the world’s first case study in the internal struggle of the defector who reaps execrations from his ex-friends while being eyed suspiciously by his new ones. His decision to switch sides marked him as a shameful figure in Jewish history, serving the emperor whose army laid bloody siege to Jerusalem.

Raphael—novelist, screenwriter, translator, and Commentary contributor—does not seek to exculpate Josephus of the self-interest that partly motivates all defectors. A Jew Among Romans is no hagiography. But he casts his subject as a Judaean Cassandra, who “tried to talk the Jews into surrender, for as long as there was any hope of averting the culminating horror.” Once his people were defeated, he chose to live: “If he was a coward because he had failed to die, he was also egregiously brave; if a traitor, it was to a reckless nationalism he never favored, not to Judaism.”

Although Jewish historians, led by Louis H. Feldman, have come to recognize Josephus’s contributions to classical and biblical scholarship, his critics remain. The most compelling, Martin Goodman, frames Josephus as a creature of the Judaean and later Roman elite and suspects that his “instinct for apologetic overcame his conscience as a historian.” But it is against Yigael Yadin’s glib epigram—“he was a great historian and a bad Jew”—that Raphael sets his argument. The real offense of this “bad Jew” was not apostasy or treason but endurance: “He survived to report news no one wanted to hear.” Josephus had admonished his Zealot compatriots against suicidal extremism. He proved horrifically prescient, and lived to record the downfall of those who dismissed him. “Memory was the vessel of Jewish solidarity,” Raphael notes. Josephus tainted the heroics with ugly facts.

The Judaea of Josephus’s time was, for Desmond Seward, an interregnal land that “had long ceased to be Israel while it was not yet Palestine.” This duality was reflected in Josephus, the Hellenistic Jew who was a rigorous follower of Jewish law; the traitor to the Jewish cause who would write a defense of Jewish history and philosophy; a Romanized Jew who, for Raphael, “was never one of them, nor could he ever again be what he was before.”

In the eyes of Josephus, his nemesis, Zealot leader John of Gischala, was a man whose “desires were ever carried to great things.” He did not intend this as a compliment. Here Raphael’s apologia runs into trouble. If we are to draw parallels between Josephus and modern-era assimilated Jews, as Raphael thinks we should, may we not also read the cautious pragmatist as a forerunner to those integrationist and internationalist Jews who agitated against the establishment of a Jewish state in the 20th century? They also damned their opposite numbers as fanatics whose needless provocations would bring misery and destruction upon Jews everywhere. The reader who wonders if Josephus would have deemed Menachem Begin a latter-day John of Gischala, obsessed with “great things,” will not be alone.

There is another significance to Josephus’s legacy often overlooked in academic debates. His narrative, the sole surviving account of the fall of Jerusalem, documents the simple but stark fact that the Jews were there. The object of much contemporary anti-Zionist scholarship is the dejudaization of Palestine—writing the Jews out of the history of the land until the 19th century in order to characterize Zionism as an alien colonialism. This revisionist project has been so successful that statements of historical fact can be judged inflammatory or (that weasel word of enforced non-offensiveness) “unhelpful.” Whenever an Israeli politician commits the sin of referring to the West Bank as “Judea and Samaria,” a sort of linguistic settlement expansion in the eyes of liberal commentators, the New York Times rushes to label these terms “biblical names.” The secular schoolmarms of Eighth Avenue deem that a demerit, but thanks to Josephus’s writings, we know that these Jewish provinces thrived long after the days of the Torah just as they thrive once again today. Wherever the borders of Israel and Palestine are drawn in an eventual peace treaty, the scholarship of this “bad Jew” reminds us to whom the land ultimately belongs.

Raphael joins a distinguished line of historians of Josephus, but few have accounted for the outcast sage so vividly. Raphael’s motion for acquittal is written in such spirited, lambent prose that he deserves to succeed where previous scholars have failed. Far from a “bad Jew,” his Josephus is a chronicler of Jewish courage, misjudgment, and ruin. A flawed character, for sure, but a consequential historian, and despite his traitorousness, a Jewish one at that.