What is the real challenge of maintaining a free society? In parshat Eikev, Moses springs his great surprise. Here are his words:Be careful that you do not forget the Lord your God . . . Otherwise, when you eat and are satisfied, when you build fine houses and settle down, and when your herds and flocks grow large and your silver and gold increase and all you have is multiplied, then your heart will become proud, who brought you out of Egypt, out of the land of slavery . . . You may say to yourself, "My power and the strength of my hands have produced this wealth for me." . . . . If you ever forget the Lord your God . . . I testify against you today that you will surely be destroyed. (Deut. 8:11-19)What Moses was saying to the new generation was this: You thought that the forty years of wandering in the wilderness were the real challenge, and that once you conquer and settle the land, your problems will be over. The truth is that it is then that the real challenge will begin. It will be precisely when all your physical needs are met – when you have land and sovereignty and rich harvests and safe homes ¬– that your spiritual trial will commence.The real challenge is not poverty but affluence, not insecurity but security, not slavery but freedom. Moses, for the first time in history, was hinting at a law of history. Many centuries later it was articulated by the great 14th century Islamic thinker, Ibn Khaldun (1332-1406), by the Italian political philosopher Giambattista Vico (1668-1744), and most recently by the Harvard historian Niall Ferguson. Moses was giving an account of the decline and fall of civilisations.Ibn Khaldun argued similarly, that when a civilisation becomes great, its elites get used to luxury and comfort, and the people as a whole lose what he called their asabiyah, their social solidarity. The people then become prey to a conquering enemy, less civilised than they are but more cohesive and driven.Vico described a similar cycle:"People first sense what is necessary, then consider what is useful, next attend to comfort, later delight in pleasures, soon grow dissolute in luxury, and finally go mad squandering their estates."Bertrand Russell put it powerfully in the introduction to his History of Western Philosophy. Russell thought that the two great peaks of civilization were reached in ancient Greece and Renaissance Italy. But he was honest enough to see that the very features that made them great contained the seeds of their own demise:What had happened in the great age of Greece happened again in Renaissance Italy: traditional moral restraints disappeared, because they were seen to be associated with superstition; the liberation from fetters made individuals energetic and creative, producing a rare fluorescence of genius; but the anarchy and treachery which inevitably resulted from the decay of morals made Italians collectively impotent, and they fell, like the Greeks, under the domination of nations less civilised than themselves but not so destitute of social cohesion.Niall Ferguson, in his book Civilization: the West and the Rest (2011) argued that the West rose to dominance because of what he calls its six "killer applications": competition, science, democracy, medicine, consumerism and the Protestant work ethic. Today however it is losing belief in itself and is in danger of being overtaken by others.All of this was said for the first time by Moses, and it forms a central argument of the book of Devarim. If you assume – he tells the next generation – that you yourselves won the land and the freedom you enjoy, you will grow complacent and self-satisfied. That is the beginning of the end of any civilization. In an earlier chapter Moses uses the graphic word venoshantem, "you will grow old" (Deut. 4:25), meaning that you will no longer have the moral and mental energy to make the sacrifices necessary for the defence of freedom.Inequalities will grow. The rich will become self-indulgent. The poor will feel excluded. There will be social divisions, resentments and injustices. Society will no longer cohere. People will not feel bound to one another by a bond of collective responsibility. Individualism will prevail. Trust will decline. Social capital will wane.This has happened, sooner or later, to all civilisations, however great. To the Israelites – a small people surrounded by large empires – it would be disastrous. As Moses makes clear towards the end of the book, in the long account of the curses that would overcome the people if they lost their spiritual bearings, Israel would find itself defeated and devastated.Only against this background can we understand the momentous project the book of Devarim is proposing: the creation of a society capable of defeating the normal laws of the growth-and-decline of civilisations. This is an astonishing idea.How is it to be done? By each person bearing and sharing responsibility for the society as a whole. By each knowing the history of his or her people. By each individual studying and understanding the laws that govern all. By teaching their children so that they too become literate and articulate in their identity.Rule 1: Never forget where you came from.Next, you sustain freedom by establishing courts, the rule of law and the implementation of justice. By caring for the poor. By ensuring that everyone has the basic requirements of dignity. By including the lonely in the people’s celebrations. By remembering the covenant daily, weekly, annually in ritual, and renewing it at a national assembly every seven years. By making sure there are always prophets to remind the people of their destiny and expose the corruptions of power.Rule 2: Never drift from your foundational principles and ideals.Above all it is achieved by recognising a power greater than ourselves. This is Moses’ most insistent point. Societies start growing old when they lose faith in the transcendent. They then lose faith in an objective moral order and end by losing faith in themselves.Rule 3: A society is as strong as its faith.Only faith in God can lead us to honour the needs of others as well as ourselves. Only faith in God can motivate us to act for the benefit of a future we will not live to see. Only faith in God can stop us from wrongdoing when we believe that no other human will ever find out. Only faith in God can give us the humility that alone has the power to defeat the arrogance of success and the self-belief that leads, as Paul Kennedy argued in The Rise and Fall of the Great Powers (1987), to military overstretch and national defeat.Towards the end of his book Civilization, Niall Ferguson quotes a member of the Chinese Academy of Social Sciences, part of a team tasked with the challenge of discovering why it was that Europe, having lagged behind China until the 17th century, overtook it, rising to prominence and dominance.At first, he said, we thought it was your guns. You had better weapons than we did. Then we delved deeper and thought it was your political system. Then we searched deeper still, and concluded that it was your economic system. But for the past 20 years we have realised that it was in fact your religion. It was the (Judeo-Christian) foundation of social and cultural life in Europe that made possible the emergence first of capitalism, then of democratic politics.Only faith can save a society from decline and fall. That was one of Moses’ greatest insights, and it has never ceased to be true.-To engage further with Rabbi Sacks’s teachings, or to sign up to his mailing list, please go to www.rabbisacks.org