The Chief Rabbi, Sir Jonathan Sacks, is one of the most engaged and engaging thinkers and commentators of our time. Books and articles pour from his pen. His thoughts of the day on Radio 4 are always insightful. His writings are always thought-provoking and often profound.

And he is nothing if not ambitious in his themes. This latest volume is no exception. It is, he says in his prologue, not just about the problems facing Jews, Judaism and Israel in the 21st century. It is also about the larger question of who Jews are, and why.

In an attempt to answer these questions the Chief Rabbi ranges far and wide. He gives us a potted history of the Jewish people — and of the State of Israel. He provides a perceptive account of the history and nature of anti-Semitism. He returns again and again to the Holocaust, the defining experience of Jews in the modern age. And these themes are enriched by myriad biblical and other quotations and allusions.

These themes are brought together in an attempt to answer the central conundrum he poses. What it is to be Jewish, “part of a singular people in a plural world, conscious at one and the same time of the uniqueness of identity and the universality of the human condition?”

He acknowledges that the problems confronting Jews in the 21st century confront others as well.

“Jews face hatred and prejudice. So do Muslims, Hindus and Sikhs in Britain, Christians in Nigeria, Buddhists in Tibet and Chinese in the Philippines. Jews worry about whether their children and grandchildren will carry on their traditions. So does every religious minority in the diverse democracies of the West.”

And Jews, he says, “must take a stand, not motivated by fear, not driven by paranoia or a sense of victimhood, but a positive stand on the basis of the values by which our ancestors lived and for which they were prepared to die: justice, equity, compassion, love of the stranger, the sanctity of life and the dignity of the human person without regard to colour, culture or creed.”

Who could disagree? But you don’t need to be Jewish to take a stand on those values. They are the universal values of liberal democracy even if the precise way in which they are translated into practical policies may lead to intense controversy.

Jews can certainly lay claim to a unique experience of the catastrophe that can occur when these values are set aside. But does that necessarily mean that they are better qualified than others to champion them in today’s world? Unless an unequivocal answer can be given to that question we surely have to look elsewhere for the answer to the fundamental question posed by the Chief Rabbi.

If, that is, there is an answer. The book does not duck the difficulties. There is a lengthy quotation from the work of David Vital, who argued in 1990 that nothing now holds the Jews together. Vital said: “Where there was once a single, if certainly a scattered and far from monolithic people, there is now a sort of archipelago of discrete islands composed of rather shaky communities of all qualities, shapes and sizes.” He concluded: “It is not too much to say that the survival of Jewry as a discrete people, its various branches bound to each other by common ties of culture, responsibility and loyalty, is entirely in doubt.”

There are two obvious answers to this. The first is that the Jewish people will survive in Israel. The second is that Judaism is, as the Chief Rabbi is quick to remind us, a faith.

As he says: “It was as a faith that Jews were born as a people, and it is as a faith that Jews will survive as a people. Leave faith out of the Jewish equation and what is left is a body without a soul.”

Does this mean that for those who are born Jewish but lack this faith, there is no prospect of survival as Jews or, more fundamentally, no purpose in survival as Jews?

The Chief Rabbi’s answer seems to be closely connected with his assertion that what he describes as the dream of emancipation died in the Holocaust. But did it?

There are countless Jews, conscious of their identity, across the world today, playing their full part in the civic societies of which they regard themselves as being a part. Some adhere to the faith (in one of its many varieties); some do not. They would surely take issue with the claim that emancipation is dead. But they would just as surely endorse one of the central messages of this book: that Judaism should not segregate itself from the world. “Segregating faith from the world,” says the Chief Rabbi, “means condemning faith to impotence within the world.”

This is perhaps the key conclusion of this very thoughtful book. It is not a book that answers every question that it poses. But it asks all the right questions and answers many of them.

And, on a subject this complex and challenging, it would be unreasonable to ask for more.

Future Tense: A Vision for Jews and Judaism in the Global Culture by Jonathan Sacks Hodder & Stoughton, £16.99 Buy this book; 304pp

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