Four generations to ruin: Ibn Khaldun on why institutions decay

Every organisation I have belonged to has told the same story about itself. There was a founding generation who did everything by hand, slept in the office and trusted each other completely. Then came growth, procedures, a new building. And then, at some point nobody can date, people began to say that something had gone. The department, the union branch, the family firm: each one remembers its founders as giants and suspects its present managers of being caretakers.

We usually treat this as nostalgia. Ibn Khaldun (1332–1406) treated it as a law, or something close to one. In the Muqaddimah, written in 1377 as the introduction to a universal history, he set out a theory of why ruling dynasties rise and fall. I teach economics, and I have come to think his theory is less about dynasties than about any institution held together by people rather than by force alone. It is worth reading that way, with some care about what it does and does not claim.

The theory in brief

The central concept is asabiyyah, usually translated "group feeling" or "solidarity": the capacity of a group to act as one, to defend each other and to accept leadership without being paid for it. Ibn Khaldun thought it was strongest where life is hard and cooperation is a matter of survival, among the desert and mountain peoples he calls badawa, bound by kinship and common defence. Settled, prosperous urban life (hadara) produces wealth, crafts and learning, but it erodes the conditions that produce solidarity.

So a group with strong asabiyyah conquers a wealthy settled society whose own cohesion has decayed. The new rulers settle. Prosperity follows, and with it luxury. Within three or four generations their cohesion is gone, and a group from the margins with its solidarity intact replaces them. Ibn Khaldun even gives a rough lifespan for a dynasty: three generations of about forty years each.

The passage I find most striking is his account of how prestige lasts four generations. The founder knows what it cost to build. His son had personal contact with the founder and learned from him, but already knows the work at second hand. The grandson follows the tradition by imitation, without understanding why things are done as they are. The fourth generation believes the position was always theirs by right, despises the virtues that built it, and loses it.

Not a moral fable

It is tempting to read this as an old moral story: hardship makes you strong, comfort makes you soft. Some of Ibn Khaldun's language invites that reading. But the mechanism he describes is more precise, and it has three parts that an economist recognises.

First, cooperation that was necessary becomes optional. The founding group cooperated because they had no alternative. Their descendants can buy what they once did for each other. Ibn Khaldun notes that late rulers come to depend on clients and hired soldiers rather than on their own people. Loyalty that was given is replaced by loyalty that is purchased, and purchased loyalty lasts only as long as the payments.

Second, knowledge becomes ritual. The third generation's imitation without understanding is the loss of tacit knowledge, the know-how that was never written down because the founders never needed to write it. Rules survive; the reasons for them do not.

Third, costs rise as capacity falls. Ibn Khaldun has a famous observation about taxation: at the beginning of a dynasty, low rates yield a large revenue; at the end, high rates yield a small one, because a heavier burden discourages the productive activity that is being taxed. Whatever you think of its modern uses, the structural point is that a declining institution tries to extract more from a base it is shrinking. He has a whole section arguing that injustice brings about the ruin of civilisation, by which he means, among other things, arbitrary seizure of property and forced labour, which destroy the incentive to produce.

None of this requires hard deserts or soft cities. It requires only that an institution be held together by a cohesion it does not know how to reproduce.

Other traditions on the same problem

Ibn Khaldun was not alone in seeing cycles. Polybius described the constitutions of Greek cities degenerating and giving way to one another, and the later book I keep beside the Muqaddimah, Max Weber's Economy and Society, describes the "routinisation of charisma": authority that begins in an extraordinary founder must, if it is to survive him, be converted into tradition or into impersonal rules.

Weber's account seems at first to offer a way out. Modern institutions, he thought, solve the founder problem with bureaucracy. Legal-rational authority does not depend on anyone feeling solidarity; it depends on offices, rules and salaries. Hobbes, from a different angle, had already argued that peace does not need fellow feeling at all, only a sovereign whom everyone has reason to obey. On these views Ibn Khaldun has described a pre-modern problem that impersonal rules were invented to solve.

I think that is half right, and the half that is wrong is the interesting part.

My argument: rules carry institutions, but do not renew them

Impersonal rules really do let institutions outlive their founders. A university can lose every member of staff and still exist; a central bank can be run by people who never met its architects. That is a genuine achievement, and it is one Ibn Khaldun's dynasties lacked.

But rules are exactly what the third generation inherits without understanding. A rule is a compressed answer to a question someone once faced. When the question is forgotten, the rule is followed mechanically, defended against change because it is old, or abandoned because nobody can say what it is for. Each of these is a form of decay, and bureaucracies are full of all three. Weber himself, in the closing pages of The Protestant Ethic, feared a rationalised order that would become an "iron cage" (Talcott Parsons's famous rendering), efficient and empty. So impersonal rules do not abolish Ibn Khaldun's cycle. They slow it, and they hide it, because the institution keeps running long after the cohesion that gave its rules a point has gone.

If that is right, then his theory tells us something practical. Institutions decay when their members stop facing the necessity that once made cooperation obvious. They renew when that necessity is made visible again: when a union branch has to fight for something, when a department has to justify a course to students who could go elsewhere, when a firm is forced to remember what its customers actually needed. Ibn Khaldun's newcomers from the margins are, in this reading, people who still face the original problem. Healthy institutions find ways to let such people in before they arrive as conquerors.

Two cautions. Ibn Khaldun's regularities are not laws in the sense physics uses; they hold often enough to be useful and fail often enough to keep historians busy. And the romance of hardship is dangerous. He never says that poverty is good, and the cities he describes as decaying are also where he locates science, crafts and the higher learning he himself spent his life in. The lesson is not to make life harder. It is that cohesion has conditions, and an institution that forgets them will go on spending its inheritance until there is nothing left to spend.

For anyone starting out, Franz Rosenthal's translation of the Muqaddimah is the standard one, and the abridged edition is a perfectly good first reading.