It was Hegel who pointed out that what history teaches is "that nations and governments have never learned anything from history, or acted upon any lessons they might have drawn from it".

Though Hegel was an idealist, this state of affairs is hardly ideal. But we may nonetheless believe he hit the nail on the head, particularly as we are reminded by this weekend's Diamond Jubilee celebrations of what has not changed. When the Queen acceded to the throne, Britain was in an era of austerity, a nation with its coffers empty, its international influence in decline and facing an uncertain future.

Indeed, unless you think George Osborne is an improvement on Rab Butler as Chancellor, and I think we can be fairly sure you don't, things may be a good deal worse than they were in 1952. There is, of course, a sizeable school of opinion which holds that the United Kingdom was a much nicer place 60 years ago; better mannered, better governed, more orderly. But then at any point in human history there is always a substantial group of people who think things were better 60 years ago and, like Evelyn Waugh's Gilbert Pinfold (and Waugh himself), dislike "everything that had happened in his own lifetime".

The truth is of course that many things have changed during the course of the Queen's reign, and many have not. Many things have improved (or, at any rate, are thought by many people to have improved) and quite a lot of things are worse.

This seems paradoxical, but fortunately we can rope in Hegel again. His big idea was that the primary characteristic of the mind was to bring together contradictions and opposing ideas and attempt to unify and synthesise them. The lesson of Queen Elizabeth's reign may be that things have changed and not changed but that, with the benefit of hindsight, neither the changes nor the things which have endured are at all what anyone would have predicted in 1952.

First and foremost is the monarchy itself. At the time of the Silver Jubilee, most people – even those who were waving their flags and throwing street parties – would have thought that the institution was under threat, and that it was an anachronism which would gradually fade away as public opinion became either indifferent or actively hostile. The Sex Pistols, at the top of the charts (officially number two, but many thought the results had been rigged) with their indictment of her "fascist regime", looked like heralds of an aggressive, undeferential, anarchic future.

But royalty has not faded – the opposite has happened. Interestingly, it is not only the Queen herself who has become more popular (which would be entirely understandable, given her remarkable success in the role), but the institution of monarchy itself. In the past 25 years, support for republicanism has never risen above 22% in the polls.

Like many supporters of a cause which attracts only a minority of the voters (those who would like to break up the United Kingdom are another example), republicans get infuriated by this, and insist it is inevitable that they will win in the end.

Anything's possible, of course. But many supposedly archaic institutions which, at the time of the Queen's coronation, progressives might have expected to vanish before the end of the 20th century are still going strong. Some, like the royal family, have shown a positive genius for adaptation.

By contrast, many dead certs among the "coming things" have failed to last the pace, or to materialise at all. The Sex Pistols (of whom we may occasionally be reminded when we hear of Dame Vivienne Westwood, or see John Lydon advertising butter on the television) now look about as much of a glimpse of the future as the Clyde Valley Stompers, and hardly any more threatening.

In the 1950s, the certainty was that bureaucracy was the best form of government. Douglas Jay, who had just left the Treasury when the Queen succeeded her father, had cheerfully written that "the gentleman in Whitehall really does know better what is good for people than the people themselves". Similar follies – the technocrats, the "white heat of technology", defences of the closed shop, purchase tax, clause 4, nationalised industry and a host of others – have proven just as short-lived, even if not all such idiocies have been disposed of.

Ronald Reagan's defence policy was going to spark a Third World War, except it ended the Cold War and brought down Communism. Three hundred and sixty-four economists wrote to the newspapers saying the Thatcher government's anti-inflation policies would never bring about economic recovery, a recovery which followed almost immediately. Gordon Brown ended "boom and bust".

These examples demonstrate that things which are thought inevitable can easily come to nothing, while things which are unthinkable can be brought about. Tony Blair, in his autobiography, gave a revealing account of how reform happens: "the change is proposed; it is denounced as a disaster; it proceeds with vast chipping away and opposition; it is unpopular; it comes about; within a short space of time, it is as if it has always been so."

What is illusory is not the possibility of change, but the inevitability of progress. The long tradition of historicism, through Judeo-Christian sacred history, Hegelianism and Marxism, views the world as a struggle for recognition, but it sees this process as a one-way movement.

It declares that you can't put the clock back, as if history were a Soviet-era Sekonda. It's a puzzling analogy, since few things are easier than putting the clock back. And Francis Fukuyama's confident declaration of "the end of history", arguing that these almost millenarian movements were bound to culminate instead in prosperous, neo-liberal democracy, now looks a little misplaced.

Even so, the track record of revolutionary projects is a good deal worse than the gradual, conservative, evolution of traditions and institutions – one reason the House of Lords hasn't yet been reformed is that all the obvious improvements would make matters worse. Oddly enough, for all his idealism, Hegel thought that a constitutional monarchy was the best possible form of government.