In 1391, the escalating persecution suffered by Iberian Jewry led to mass conversions, which continued as the Jews’ situation worsened. The presence of large populations of former Jews, and the return of some of their descendants to Judaism in subsequent generations, challenged the way both Jews and Gentiles understood Jewish identity. David Graizbord explains how:

By . . . 1415, some half to two-thirds of Castilian and Aragonese Jews had become titular Christians. Irrespective of the sincerity [of their conversions], or lack thereof, in many if not most cases the converts and their immediate, baptized descendants still lived among, or relatively close to, Jews and had extensive social, economic, and familial relations with them. This meant that for the first time, the religion and the ethnicity of tens of thousands of people once known and still widely regarded as “Jews” were at odds: these “New Christians” were “Jewish” as concerned their social and economic relations, their ethnic culture, and their social reputation, yet their religious identity was at least theoretically identical to that of the majority population.

Of particular interest in this connection is the promulgation as early as 1436 of private and municipal statutes of “Purity of Blood.” This concept formally recast and stigmatized Jewishness as a matter of descent rather than of official religious status, much less of demonstrable belief and behavior. Equipped with this new notion of purity, “Old Christians” began to treat questions of morality and religious fealty as matters of familial heredity.

For their part, Jews acquired a correspondingly acute consciousness of their genealogy. . . . Jewish letters of introduction from the late 1300s and early 1400s, [i.e. from when mass conversion began], differ from older ones in explicitly distinguishing between “good” Jewish families—that is to say, families whose members had not converted—and families sullied by Christianization. A fateful message of the letters was that while Iberian Jews may share ethnicity, their differing fealty to God rendered them essentially separate. What now mattered for purposes of determining a Jew’s character as a Jew, was not only the quality of his or her behavior as an observer of mitzvot, but the caliber of his or her yiḥus [lineage].

Ayatollah Ruhollah Khomeini, the founder and supreme leader of the Islamic Republic of Iran, issued a fatwa (religious ruling) in 1989 calling for believers to murder the novelist Salman Rushdie due to the content of his novel, The Satanic Verses. Over the years, two of the book’s translators have been stabbed—one fatally—and numerous others have been injured or killed in attempts to follow the ayatollah’s writ. Last week, an American Shiite Muslim came closer than his many predecessors to killing Rushdie, stabbing him multiple times and leaving him in critical condition. Graeme Wood comments on those intellectuals in the West who have exuded sympathy for the stabbers:

In 1989, the reaction to the fatwa was split three ways: some supported it; some opposed it; and some opposed it, to be sure, but still wanted everyone to know how bad Rushdie and his novel were. This last faction, Team To Be Sure, took the West to task for elevating this troublesome man and his insulting book, whose devilry could have been averted had others been more attuned to the sensibilities of the offended.

The fumes are still rising off of this last group. The former president Jimmy Carter was, at the time of the original fatwa, the most prominent American to suggest that the crime of murder should be balanced against Rushdie’s crime of blasphemy. The ayatollah’s death sentence “caused writers and public officials in Western nations to become almost exclusively preoccupied with the author’s rights,” Carter wrote in an op-ed for the New York Times. Well, yes. Carter did not only say that many Muslims were offended and wished violence on Rushdie; that was simply a matter of fact, reported frequently in the news pages. He took to the op-ed page to add his view that these fanatics had a point. “While Rushdie’s First Amendment freedoms are important,” he wrote, “we have tended to promote him and his book with little acknowledgment that it is a direct insult to those millions of Moslems whose sacred beliefs have been violated.” Never mind that millions of Muslims take no offense at all, and are insulted by the implication that they should.

Over the past two decades, our culture has been Carterized. We have conceded moral authority to howling mobs, and the louder the howls, the more we have agreed that the howls were worth heeding. The novelist Hanif Kureishi has said that “nobody would have the [courage]” to write The Satanic Verses today. More precisely, nobody would publish it, because sensitivity readers would notice the theological delicacy of the book’s title and plot. The ayatollahs have trained them well, and social-media disasters of recent years have reinforced the lesson: don’t publish books that get you criticized, either by semiliterate fanatics on the other side of the world or by semiliterate fanatics on this one.