Eventually, nearly every discussion of the Jews, pro or con, sympathetic or hostile, gets around to their alleged singularity. Twelve or thirteen centuries ago, when everyone from the Indus to the Atlantic was choosing sides between the crescent and the cross, the Jews were sticking to a path all their own, studying their own books, formulating their own laws and rejecting everyone else's. They were stubborn, clannish and standoffish, and even when they stopped wearing those funny clothes in the modern era and tried to blend in--especially when they tried to blend in--something about them remained at odds with the larger society. ...

Fitzgerald and Hemingway made more or less the same point, so there had to be something to it. All agreed that the Jews were out of place wherever they went. They were nowhere at home because nowhere was their home. They were different.

... In The Jewish Century ... Yuri Slezkine, a Russian-Jewish historian now ensconced at Berkeley, mounts an elaborate counterargument. Jews are not unique, he maintains in his fascinating new study, and it is only European provincialism that makes them seem that way. Otherwise, they are of a type that is very common the world over: border crossers, ethnic transgressors and other nomadic and seminomadic elements who enter into complicated relations with host nations that are complementary and symbiotic. We think of the Jews as singular because over the course of Western history they have performed singular functions: as intermediaries between the Christian and Muslim realms during the early Middle Ages and then as moneylenders and pawnbrokers when an expanding European economy led to a growing need for capital. These were functions that Europeans (which is to say, Christians) could not or would not do for themselves, thanks to a strict church ban on usury. So they turned to outsiders--intimate strangers, so to speak--to do them instead.

The result, among other things, was a deeply ambivalent relationship that multiplied itself in a variety of ways. Both sides were contemptuous of the other but also envious. Both needed the relationship to continue but wished they could do without. The Jews, being militarily vulnerable, had to be especially careful. They had to make themselves at home while at the same time insisting that their real home was far away (in Jerusalem, of course). They had to know their customers while making sure their customers did not know them. They had to be alert for opportunities but at the same time on guard for signs of trouble.

Strange--except that other ethnic groups have carved out parallel roles for themselves in a variety of circumstances. In medieval Korea, according to Slezkine, the Koli such'ok and Hwach'okchaein peoples specialized as hunters, butchers, sorcerers, torturers, border guards, buffoons, dancers and puppeteers. In Japan, a group known as the Eta specialized in "animal slaughter, public executions, and mortuary services," while a group known as the Hinin "monopolized begging, prostitution, juggling, dog training, and snake charming." In Somalia, the Yibir people engaged in magic, surgery and leatherwork; in southern Ethiopia, the Fuga were ritual experts and entertainers; in the Sahel, Sahara and Sudan various traveling blacksmiths doubled as cattle dealers, grave diggers, circumcisers, peddlers, jewelers, musicians and conflict mediators. Again, these were functions that the people they traveled among could not or would not do themselves and that they likewise delegated to others. We can imagine the similarly mixed emotions such itinerant specialists aroused whenever they pulled into a new village or settlement. Although some people might regard anti-Semitism as somehow sui generis, Jews are not the only ones to arouse both envy and disdain, welcoming and trepidation. They are also not the only ones to regard their social role as unique and therefore indispensable and to encourage others to think the same.

Slezkine has a name for such specialists. He calls them Mercurians and their hosts Apollonians. In Greek mythology, Apollo is the god of livestock and agriculture and hence of settled existence in general. Hermes--Mercury to the Romans--is, by contrast, a trickster god who serves as "the patron of rule breakers, border crossers, and go-betweens," i.e., less permanent types who prefer to live by their wits. Rather than settling down and blending in, the Mercurians seek the opposite goal: to keep themselves apart by deliberately cultivating strangeness‚ strange customs, strange languages and so on. Gypsies developed a variety of Romani and Para-Romani languages whose chief purpose, non-Gypsies have long suspected, is to keep outsiders in the dark. The Inadan gunsmiths and jewelers of the Sahara make themselves incomprehensible to their Tuareg hosts by adding the prefix om- or the suffix -ak to certain nouns. Jews have created a variety of languages out of Arabic, Persian, Portuguese, Spanish, French and Italian, among others. Although long regarded as a German dialect that they picked up crossing the Rhine, Yiddish, according to one linguist, may actually be a more complex "fusion language" composed of equal parts German, Hebrew, Loez (Judeo-French and Judeo-Italian) and Slavic, a mélange whose overall purpose is similarly communicative and noncommunicative--to facilitate communication within the community, that is, while erecting a linguistic barrier around it. Jews learned other people's languages, but other people rarely learned the Jews', a one-way linguistic street that was not without its advantages. ...