BOOK REVIEW / One faith, two worlds: 'Piety and Power: The World of Jewish Fundamentalism' - David Landau: Secker, 20 pounds

THE hermetic world of Jewish fundamentalism is an enigma to many Jews and non-Jews alike. The fundamentalists were, for example, against the recent controversial proposal by mainstream Orthodox Jews to erect an eruv in Barnet last month - much to the mystification of the many flag-waving non-Jews who also opposed the scheme. Their concept of reality may seem unreal and bizarre, yet they claim the adherence of multitudes worldwide. David Landau's odyssey through their culture offers a rare glimpse into a unique way of thinking.

Modernity gave Jews a choice as to how they define themselves. Some chose assimilation and attempted to transcend their Jewishness. Some embraced variants such as Reform Judaism or Jewish nationalism. But others simply turned their backs and rebuilt the ghetto walls, living their lives according to halakah (Jewish law). These fundamentalists, who live today in Stamford Hill or Williamsburg or Jerusalem, are known by the blanket term haredim, which literally means 'God-fearing'. To the outsider, their black garb and almost obligatory beard makes them indistinguishable, but the type of hat, the position and length of their peyot (side-curls), and the presence or absence of a gartel (a rope-like belt) communicate their different allegiances and philosophies.

Landau explains that haredi culture is built on three basic precepts: the observance of the Sabbath; the keeping of the dietary laws; and taharat hamishpacha, the purity of the family. Outside marriage, men and women are strictly separated. As Landau points out, 'some Hasidic women wear only thick black stockings. In other slightly more modern haredi circles, black or any coloured tights are thought to be too suggestive, and only flesh-coloured hose is allowed. Each group has its own by- laws about how many denier thick the stockings must be.' Some married women wear sheitels (wigs), others scarves or hats to prevent their plumage attracting members of the opposite sex. The Gerer Hasidim, regarded as the strictest in this regard, will not even use the term 'wife' to describe their partners in the presence of other men, for fear of sexually inflaming them. Within marriage, a 'positive' attitude towards sexuality is encouraged: haredim, including rabbis, are expected to produce large families.

Landau's chapter on haredi behaviour during the Holocaust is both harrowing and bewildering. Thousands went to their deaths silently and largely uncritical of their teachers, still attempting in the camps to live - and to die - by the tenets of Jewish law. In that hell, they imposed their unworldly reality so as to survive spiritually before their physical extermination.

Their faith provided the few survivors with the raison d'etre to go on and to regenerate their destroyed communities. Today there is an estimated 50,000-strong 'society of learners' studying in yeshivot (seminaries), a far higher figure than in pre-war Poland and Lithuania. In Israel, some haredim regard themselves as still being in exile, since only the coming of the Messiah will bring the true Jewish homeland.

Landau's style is one of studied neutrality. Yet it can be argued that while the haredi communities do exude a protective warmth and boast a crime- free environment, they allow little intellectual dissent. There is a Soviet conformity to their literature and outlook which conflicts with the traditional Jewish emphasis on argument and discussion. And the cult of personality surrounding the almost papal figure of the Rebbe (rabbinical leader) does not find favour among many Jews.

The rift between the enclave Judaism of the haredim and the Jewishness of secularists and traditionalists raises the question: will the Jews split and eventually become two peoples?