A few things pointy-heads should know

All Souls fellowships are for the seriously brainy. Harry Mount, like Belloc and Lord Dacre, failed

If you happen to be in Oxford at the moment and find yourself strolling down the High Street, you might catch a group of 30 or so people in their early 20s, nervous but determined-looking, filing through an oak door into one of the medieval buildings that line the street. Look closely, for among their number may be the geniuses of the next millennium. That door is the door to All Souls college, and the 30 people are this year's entrants for the All Souls fellowship examination.

If intelligence can be measured by exams, the All Souls Fellows by examination are the cleverest people in the country. There is some debate over which is the hardest exam in the world. Honour moderations in classics, again at Oxford, were the holders of the title for years, with their 12 three-hour exams over six days. They were usurped this century by the Chinese civil service entrance examination, a ten-day, all-day ritual. But in terms of the quality of the candidates, there is probably nothing to rival the All Souls exams, which began on 30 September and last for three days.

Founded in 1438 for poor scholars by Archbishop Chichele, All Souls was to be a place of learning for the non-monastic clergy and a place of prayer, a chantry for all souls of the faithful departed, associated particularly with the late king, Henry V, and those who died in the Hundred Years' War with France. It has changed since then, but remains the only medieval foundation to have retained its original intention as being an entirely graduate college.

Until the late 19th century, the Fellows were not a particularly distinguished lot, installed mostly by virtue of blood ties to the original founder. But in 1878 the prize fellowships were set up, and the college began to attract the great minds of England.

Invitations to sit the exam are sent only to those who have got a First in their finals. Only those who have graduated within the past three years are eligible - hence, most of the candidates are under 25. Of the 500 who take Firsts every year, only 30 apply, to fight for two fellowships each year. Both last seven years, but are usually extended. One is purely academic - the winner researches full time on anything they want to. The late A L Rowse and the late Sir Isaiah Berlin were both originally academic Fellows. The other fellowship goes to a star who has opted for a non-academic career - typically the law, politics or journalism. John Redwood, William Waldegrave and Matthew d'Ancona, deputy editor of the Sunday Telegraph, are non-academic Fellows, known as "Londoners" by the academics. (The name of Colin Dexter's famous detective was inspired by a Londoner - Sir Jeremy Morse, now chancellor of Bristol University.)

The Londoners are obliged to do nothing, but are expected to publish something scholarly and dine regularly at the college. Redwood, for instance, on leaving Oxford and gaining his fellowship, spent his days working for a merchant bank and his evenings writing a thesis: The Fear of Atheism in England from the Restoration to Berkeley's Alciphron.

Part of the attraction of the fellowship is financial. The sum of £9,000 a year is useful for the aspiring lawyer and a real bonus for an academic. But more alluring is the kudos. The intellectual connotations of an All Souls fellowship are significant and the struggle to get one intense. Hilaire Belloc, John Buchan and Lords David Cecil and Dacre all failed the exam. David Gilmour, in Curzon, his life of Lord Curzon, viceroy of India and almost prime minister in the 1920s, describes how upset Curzon was on getting a Second in his classics finals. He "thought a Second would be so humiliating and make his life so insupportable that he would have to retire somewhere and hide his face from the world". Curzon wrote that he would devote his future to "showing the examiners that they had made a mistake". The best way of showing them was to win the All Souls fellowship which, after a year's study, including a volume of Gibbon every two days, he duly did.

There were no signs of future eminence among the candidates when I took the exam in 1994. If anything, there was a general feeling of embarrassment; we had all chosen to spend three days doing this gruelling exam and we had really chosen to do so for one reason only - because we wanted to show how brilliant we all were. The young lawyers and academics, for that is what they mostly were, swapped tales of how unlikely success was and how they had not really wanted to take part.

Yet there can be few more pleasant rooms to sit an exam in than the hall of All Souls, into which we were led on our first morning by the Manciple - the college steward. Even with an eye on the staggering list of alumni, there is a resonance to what John Strachey, writer and politician, said of the buildings and their inhabitants: "the birds are not worthy of the cage". Built by Hawksmoor in the early 18th century, the hall is Gothic without and classical within - shell-headed niches and an Ionic screen are topped by a ceiling lined with ornate Baroque pouches. Ranged around the room are portraits of Fellows ancient and modern. (Women had to wait until 1979 and the wardenship of Sir Patrick Neill, the chairman of the Committee on Standards in Public Life.)

There are six papers in the exam, each of three hours (one each morning and afternoon). The first two, specialist papers on the subject you did for your finals, were not unlike finals but with a little extra spice to the questions: "Consider the problems raised by one or more of the following for those with property in Britain in any period of your choosing: dowagers; daughters; younger sons; bastards."

The two general papers on the second day test for a broad erudition that cannot be effectively revised for, with a mixture of topical and philosophical questions: " 'If a man could say nothing against a character but what he could prove, history could not be written' (Samuel Johnson). Discuss."

The general papers are mere limbering-up exercises for the toughest test, held on the morning of the third day, simply called "Essay". We were presented with a sheet of A4 with one word on it: "miracles". Past years have thrown up the words "chaos" and "mercy". A L Rowse wrote on "possessions". The general nature of the question meant that there was room for pretty much any answer and, by inference, infinite room for brilliance and invention.

I struggled through with some thoughts on all the miracles I had ever heard of - weeping Madonnas, liquefying saint's blood - some very basic definitions of the word miracle and a conclusion about miracles being a battle between faith and cynicism.

Towards the end of the three hours, I glanced at a neighbour's rough plan. Beneath the first sub-heading, "Popper and the proving of miracles", stretched a page-long list of Karl Popper's works, each of them summarised in note form.

The last paper - translations - consisted of a variety of passages in different languages: ancient and modern Greek; ancient and medieval Latin; French; German; Italian; Spanish; Russian; ancient Hebrew. On going in, I felt confident about the Latin passage I was going to concentrate on until I heard my neighbour, the one who had written about Popper, confide in a friend: "Isaiah Berlin did five. I'm going to try four."

The examiners concentrate particularly on the essay and the two general papers, which give a better impression of intelligence in depth. It takes a month to mark the papers and then invitations are sent out to the shortlisted candidates to dine, one by one, in college. I did not receive an invitation. Again, it is not made clear what behaviour is expected at the dinner, but a clue is given in its slang name, "the knife-and-fork test". The implication is that those candidates considered academically sound enough to pass the exam stage should also be able to engage in mature, cosmopolitan conversation and know their way around a dinner table. Cherry pie is served to see what the candidates do with the stones. A L Rowse thought that the best thing to do was swallow them. He was elected, but was still not sure, 70 years later, whether he was right to do so.