As perhaps the only Oxford University-educated bullfighter in history, Alexander Fiske-Harrison is not a man easily scared.

The fact his talk at Blackwell’s in Broad Street scheduled for today led to “a credible threat” from an animal rights extremist left him unmoved.

News was to quickly follow that the event had been postponed.

Hosting a talk on bullfighting at the very time that animal rights demonstrators would be gathering just around the corner in South Parks Road (to protest outside a university science building) might not have been the greatest piece of timing since El Cordobes wafted a red cape.

But Mr Fiske-Harrison, 35, seemed disappointed rather than fearful as he recounted: “Blackwell’s tell me that the police have said the talk’s time has to be moved after receiving a credible threat from a known person or persons vis-a-vis animal rights.

“I can’t work out if they either lack the police to secure the building at the original time, or whether Blackwell’s is unhappy with the sum of money the police have asked for to secure it. Either way, speech is only free at certain times of day it would seem.”

The great irony is that this author was once an undergraduate at Oxford University’s Faculty of Zoology, inspired, he says, to study there by his love of animals.

However, a family outing to a bullfight on his first visit to Spain in 2000, aged 23, led to an obsession with bullfighting that has come to dominate his life.

He spent two years in Spain’s heartland of bullfighting, hanging out with matadors and breeders, talking with fans, running with bulls in Pamplona — and ultimately training to fight bulls himself.

His book, Into The Arena: The World of the Spanish Bullfight, was hailed — at least by those who can stomach the event — as the most engaging study of bullfighting since Hemingway’s Death In the Afternoon.

Arguably, he took his passion for blood and sand significantly further even than the Nobel-winning novelist.

For his book ends with Mr Fiske-Harrison plunging a sword into a three-year-old bull, killing the animal at the third attempt, watched by 100 people.

He may have emerged from the ring without injury but his bid “to understand the bullfight at its deepest levels” is presenting new dangers now he is back living in Oxford.

“I have had so many death threats. The subject raises such strong emotions in people, even though in my book I tried to treat it in the most balanced way I could.

I’ve been told ‘I should be tortured to death’. I just don’t know what compels people to be so extreme.”

Euan Hirst, Blackwell’s academic manager, said the talk would be held on February 9.

He said: “Due the controversial nature of the subject and the high level of interest in the event we have decided to rearrange the talk, to ensure Mr Fiske-Harrison can be heard in a safe environment and a moderated debate may be properly conducted.”

Mr Fiske-Harrison had a taste of what was to come at the William Hill Sports Book of the Year Awards for which he was shortlisted, held at Waterstone’s in Piccadilly.

“I stepped outside for a cigarette and a big guy walked over to me,” he recalled. “It turned out he was the security hired to protect me. I learned that there had been threats and that it was the first time in 23 years they had had to hire security — and it was all down to my book.”

But he is showing no inclination to step out of the ring, having already accepted an invitation to attend a conference in Easter on the future of bullfighting in Seville, which will launch the new season.

His decision to explore the world of bullfighting followed an article for Prospect magazine.

The final paragraph said: “Whether or not the artistic quality of the bullfight outweighs the moral question of the animals’ suffering is something that each person must decide for themselves — as they must decide whether the taste of a steak justifies the death of a cow.”

By then his days as a biologist were long behind him.

His dislike of laboratories had led Mr Fiske-Harrison, a student at St Peter’s College, to switch to PPE. As well as working as a journalist, he wrote a play, The Pendulum, and acted in it when it opened in a small West End theatre.

With his Prospect essay becoming the most commented on article in the magazine’s history, Mr Fiske-Harrison needed little persuading when his literary agent suggested a book on bullfighting.

But he did not foresee that his bullfighting quest would lead him into the ring, cape and sword in hand. Bullfighters and bull owners were initially deeply suspicious about a writer from Oxford seeking to learn the real truth about bullfighting.

The book does not shirk from the issue of cruelty and whether aesthetics justify the suffering of the animal.

But as to whether it should be viewed as an art form or gaudy, blood-filled circus spectacle, there is little doubting on which side of the fence Mr Fiske-Harrison stands.

Robert Pittam, a lifelong opponent of bullfighting, believes that while bullfighting has slipped from the general public consciousness, a new generation of aficionados has emerged in England, emphasising culture, drama, history, and the free range lifestyle of bulls destined for the ring.

But Mr Pittam says the Oxford writer’s philosophical journey “is nothing more than a monumental ego trip”.

“Regardless of the cunning sophistry of the bullfight apologists, one single moral question persists,” says Mr Pittam. “Can it ever be right to torment, mutilate and torture a captive animal for human pleasure?”

Mr Fiske-Harrison relished the chance to take part in the world famous bull run through the streets of Pamplona — “a bloody day: two in intensive care, two other serious gorings, a dozen minor injuries from human or bovine feet”.

But it is his decision to move from being an observer to a participant in the killing of a bull that will damn him in many eyes.

He accepts that his research into the experience of the matador simply went further than he expected. “The world of the bullfight had drawn me into its heart which was what I had wanted, but in doing so it had won my affections, which was worrying,” he writes.

“I decided that I must represent the world of the bullfight as it is. And the only way to do that, I decided, was to go over the horns, sword in hand.”

The training, the passes and the aching muscles are described in detail, but it is the chilling account of the bullfight, staged in a ring on a farm, that lingers in the memory.

The bull was younger and significantly lighter than the animals fought by professional matadors. Its end is not swift, with the sword point twice striking bone.

When the sword is plunged in behind the proper killing spot, the writer is convulsed with dread that he has injured the bull horribly but not killed it.

He describes what happens next: “The people in the crowd were calling me to gesture as the matador’s gesture for victory. For the bull was dying. I could see his legs shaking now. However, the idea of bouncing on my toes and gesturing outwards with my hands, to demand that the bull die on my command as real matadors do, I simply could not bring myself to enact. It seemed to me it would be crowing over a fallen enemy.

“All I could do was watch his slow and inexorable descent into darkness. He fell, first to his fore-knees, then to the floor. He never let out a cry, nor any signal of despair, just the slow shutting down of control.”

So how did he feel afterwards?

“I was washed over with the feeling of what I had done. It was a thousand things at once. Guilt, shame, happiness, elation, pride, vanity, and a profound grief and loneliness. I felt that I knew him, that I had got to know him in the moments before his death.”

But it seems even this has not been enough. For Mr Fiske-Harrison is considering fighting more bulls, with another nine needed to secure a novice’s licence.

“I don’t know if I can do that. It will take a lot of time and it is terribly dangerous. But it feels unfinished. It is very hard to give up. It is a subject that does not easily let go. Everyone has a limit to what they can do in the ring. I don’t know what mine is.”