Who is the Dr Thomas Arnold of the comprehensive schools? There does not appear to be one. Socialists and egalitarians have an unshaken faith in the virtue of the comprehensive ideal. But they have failed to call forth the inspiring figure who could offer, in his or her own school, an elevated demonstration of the ideal put into practice. It is all very well to wear a T-shirt bearing a picture of a Latin American revolutionary, if anyone still does, but Che Guevara wasn’t running a school. The socialists suffer from an acute shortage of constructive heroes, which is why the Soviet Union was reduced to inventing such ludicrous ones.

But this is not just a problem for socialists. As headmaster of Rugby from 1828 to 1841, Dr Thomas Arnold sought to instil “1st, religious and moral principles: 2ndly, gentlemanly conduct: 3rdly, intellectual ability.” The new or revived public schools of the 19th century had all sorts of practical purposes, being designed to enable their pupils to pass the exams which permitted entry to various professions, and to provide an imperial ruling class. But the education they offered was saved from becoming aridly utilitarian because they were devoted to the formation of Christian gentlemen. One of the distinguishing marks of a gentleman was that he did things because he knew they were the right thing to do, not because they would bring him personal advantage. Captain Oates was a very gallant gentleman.

The idea of a gentleman was a more inclusive one than it sounds to modern ears. One of its greatest advantages was that you could define it so as to include yourself. You could behave like a gentleman, without possessing any of the social attributes which a gentleman might have: there was no need to possess a coat of arms, or a country estate, or engage in field sports, or wear evening dress. At least since Chaucer’s time, there had been a distinction between the social meaning of the word, and the moral. It was evident that well-born people, who ought to know how to behave like gentlemen, did not always do so, while others sometimes did.

Philip Mason, whose perceptive study, The English Gentleman, was published in 1982, argues that “the desire to be a gentleman” runs through and illuminates English history from the time of Chaucer until the early 20th century. He suggests that “for most of the 19th century and until the Second World War” the idea of the gentleman “provided the English with a second religion, one less demanding than Christianity. It influenced their politics. It influenced their system of education; it made them endow new public schools and raise the status of old grammar schools. It inspired the lesser landed gentry as well as the professional and middle classes to give their children an upbringing of which the object was to make them ladies and gentlemen, even if only a few of them also became scholars.”

This was a subject that interested so great a man as Cardinal Newman. In The Idea of a University he said that a liberal education makes “not the Christian, not the Catholic, but the gentleman”, and went on:

It is well to be a gentleman, it is well to have a cultivated intellect, a delicate taste, a candid, equitable dispassionate mind, a noble and courteous bearing in the conduct of life; these are the connatural qualities of a large knowledge; they are the objects of a University . . . but they are no guarantees for sanctity or even for conscientiousness; they may attach to the man of the world, the profligate, the heartless.

Which is why for Dr Arnold, the Christian basis of education took priority. His headmastership came at a time when the public schools were notoriously dissolute. At Eton, John Keate, headmaster from 1809-1834, sought to assert some degree of control by mass floggings. But in 1834 the Quarterly Journal of Education reported that “before an Eton boy is ready for the University he may have acquired . . . a confirmed taste for gluttony and drunkenness, an aptitude for brutal sports and a passion for female society of the most degrading kind, with as great ease as if he were an uncontrolled inhabitant of the metropolis.” Public opinion would no longer tolerate this kind of thing. It looked for moral leadership, and three years before Queen Victoria ascended the throne, the new headmaster of Rugby stepped forward with charismatic earnestness to provide it. Arnold’s sermon on “Christian Education”, preached in Rugby Chapel, begins: “This is the simplest notion of education; for, undoubtedly, he is perfectly educated who is taught all the will of God concerning him, and enabled, through life, to execute it.” Arnold expected his praepostors, or prefects, to work with him, and with God, to defeat evil.

It is difficult to disentangle what Dr Arnold was really like from the heroic legend constructed around him after his death in 1842 aged only 46. His former pupils sang his praises: Arthur Stanley, later Dean of Westminster, in The Life of Arnold, published in 1844, and Thomas Hughes in Tom Brown’s Schooldays, published in 1857. Many of Dr Arnold’s carefully chosen staff revered him and went on to become headmasters too. His fame grew throughout the 19th century and in 1896 a bust of him was erected in Westminster Abbey, alongside one of his son, the poet and critic Matthew Arnold.

Dr Arnold’s personal influence naturally diminished as those who had known him died. As Alicia C. Percival remarks in Very Superior Men, her study of some early public school headmasters: “The practical use of prefects in a school society remained . . . but the search for the Christian community —though no 19th century public school head would have wished to be considered as having abandoned it — appeared less urgent.”

When Matthew Arnold wrote his poem “Rugby Chapel”, he distinguished between men like his father, who were

Not like the men of the crowd

Who all round me to-day

Bluster or cringe, and make life

Hideous, and arid, and vile;

But souls tempered with fire,

Fervent, heroic, and good,

Helpers and friends of mankind.

But Arnold also recognised, in his far better known “Dover Beach”, that the certitudes of his father were in retreat:

The Sea of Faith

Was once, too, at the full, and round earth’s shore

Lay like the folds of a bright girdle furled.

But now I only hear

Its melancholy, long, withdrawing roar,

Retreating, to the breath

Of the night-wind, down the vast edges drear

And naked shingles of the world.

In 1918, Dr Arnold was one of the Eminent Victorians mocked by Lytton Strachey, in his book of that name. Bloomsbury found such earnestness ridiculous, but they were not the only writers who noticed that things had changed. In Evelyn Waugh’s Decline and Fall, which appeared in 1928, the public schools are represented by the rackety Captain Grimes, a man of whom Dr Arnold would not approve, while Paul Pennyfeather, a dim undergraduate to whom things happen, has to return Dean Stanley’s Eastern Church to the college chaplain after being sent down from Oxford. Pennyfeather gets the book back when he returns to the university and resumes his life of obscurity.

For Waugh, Christianity could no longer be the great animating principle that it was for Dr Arnold. I do not want to exaggerate this change. Much of the life of the Church of England, and of the other churches, flows underground, or at least quite unnoticed. To some people and some schools, perhaps more than we realise, Christianity remains of defining importance. But as a rallying cry, it will not do. Secular intellectuals inform us that even to use the expression “Christian name” is offensive to members of other faiths.

Something similar has happened to the idea of the gentleman. It too flows on underground, which makes it hard to estimate how much strength is left in it. I would guess that at least half the present Cabinet think of themselves as gentlemen. The prime minister is clearly a Christian gentleman. His Anglicanism is an essential part of him, and one that few of the political commentators now writing have the faintest hope of understanding. Nor if they understood it would they approve of it. No wonder he tries to modernise himself, and shed any trace of being a starchy, old-fashioned upholder of marriage, by informing us at every possible opportunity that he is also in favour of gay marriage. What an Anglican concession that is to the spirit of the age: faintly painful to himself, at least until he gets used to it, a self-mortification which shows how genuinely willing he is to compromise, but which also starts to look a bit obsessive.

David Cameron’s gentlemanliness is, he fears, an even worse political handicap. If it were generally recognised that he is a gentleman, this would be taken by ill-natured people, including the columnists mentioned above, as conclusive evidence that he is snobbish and out-of-date. There would be a wilful confounding of the social and moral senses of the word “gentleman”, by chippy individuals who have never been elected to anything, not even the Bullingdon Club.

So the prime minister yields to the temptation to play down that side of himself, with the unfortunate result that he sounds, as we nowadays say, less “authentic”. The late Shirley Letwin argues, in The Gentleman in Trollope, that there is an unselfconsciousness about a gentleman’s morality, and wonders: “Can an inherited moral practice maintain its character once it is reflected upon self-consciously?” Dr Letwin compares this morality to “a language which has long been spoken by people who do not themselves recognise its grammar, who even lack the concept of grammar”. In her book, she identifies with marvellous discrimination the grammar of the gentlemanliness found in Trollope’s novels.

It is impossible to think of a modern novelist whose work would reward such study. There is a gap in our culture: we have lost the gentleman without replacing him. That, perhaps, was part of the difficulty with comprehensive schools. They were meant to bring about greater equality, but we did not quite know, at the individual level, what they were aiming to achieve; what kind of men and women they were hoping to produce. I am not, incidentally, seeking to imply that in the days when the Christian gentleman was a recognised type, everyone behaved well. Christians are not always Christian. Crimes, follies and misfortunes will always occur. But to have an elevated standard of conduct increases the chances that some people will live up to it, as well as the danger of failure and hypocrisy.

It is not my contention that comprehensive schools are necessarily useless. There is a charm in the idea of educating the members of a community together. But the purposes of that education cannot be reduced to a string of mushy platitudes, framed in such a way that nobody is offended and hardly anyone falls short. Nor, now that we are taking steps to tighten things up, can we achieve this by setting targets. Five good GCSEs are no doubt preferable to five bad GCSEs, but that sort of approach leads if we are not careful to a barren utilitarianism, with every moral or spiritual consideration forgotten in a race to see who can jump through the largest number of utterly tedious hoops: a death of the soul which can afflict fee-paying schools too, as selfish parents urge their over-burdened children forward.

The gentleman has retired from the fray, but we still need an ideal of good conduct: something that is not the same as Christian behaviour, but which helps to raise us above boorish self-seeking; an ideal which includes modesty, magnanimity and the willingness to sacrifice oneself for the sake of others, especially those who are weaker.