In Dublin, not long ago, Richard Dawkins visited a steakhouse called Darwin’s. He was in town to give a talk on the origins of life at Trinity College with the American physicist Lawrence Krauss. In the restaurant, a large model gorilla squatted in a corner and a series of sepia paintings of early man hung in the dining room – though, Dawkins pointed out, not quite in the right chronological order. A space by the bar had been refitted to resemble the interior of the Beagle, the vessel on which Charles Darwin sailed to South America in 1831 and conceived his theory of natural selection. “Oh look at this!” Dawkins said, examining the decor. “It’s terrific! Oh, wonderful.”

Over the years, Dawkins, a zoologist by training, has expressed admiration for Darwin in the way a schoolboy might worship a sporting giant. In his first memoir, Dawkins noted the “serendipitous realisation” that his full name – Clinton Richard Dawkins – shared the same initials as Charles Robert Darwin. He owns a prized first edition of On The Origin of Species, which he can quote from memory. For Dawkins, the book is totemic, the founding text of his career. “It’s such a thorough, unanswerable case,” he said one afternoon. “[Darwin] called it one long argument.” As a description of Dawkins’s own life, particularly its late phase, “one long argument” serves fairly well. As the global face of atheism over the last decade, Dawkins has ratcheted up the rhetoric in his self-declared war against religion. He is the general who chooses to fight on the front line – whose scorched-earth tactics have won him fervent admirers, and ferocious enemies. What is less clear, however, is whether he is winning.

Over dinner – chicken for Dawkins, steak for everyone else – he spoke little. He was anxious to leave early in order to discuss the format of the event with Krauss. Though Dawkins gives a talk roughly once a fortnight, he still obsessively overprepares. On this occasion, there was no need – he and Krauss had put on a similar show the night before at the University of Ulster in Belfast. They had also appeared on a radio talkshow, during which they had attempted to debate a creationist (an “idiot”, in Dawkins’s terminology). “She simply tried to shout down everything Lawrence and I said. So she was in effect going la la la la la.” Dawkins stuck his fingers in his ears as he sang.

Krauss and Dawkins have toured frequently as a double act, partners in a global quest to broadcast the wonder of science and the nonexistence of God. Dawkins has been on this mission ever since 1976, when he published The Selfish Gene, the book that made him famous, which has now sold over a million copies. Since then, he has written another 10 influential books on science and evolution, plus The God Delusion, his atheist blockbuster, and become the most prominent of the so-called New Atheists – a group of writers, including Christopher Hitchens and Sam Harris, who published anti-religion polemics in the years after 9/11.

An hour or so after dinner, the Burke Theatre in Trinity College, a large modern lecture hall with banked seating, was full. After separate presentations, Krauss and Dawkins conversed freely, swapping ideas on the origins of life. As he spoke, Dawkins took on a grandfatherly air, as though passing on hard-earned wisdom. He has always sought to inject beauty into biology, and his voice wavered with emotion as he shifted from dry fact to lyrical metaphor.

Dawkins has the stately confidence of one who has spent half a life behind a lectern. He has aged well, thanks to the determined jaw and carved cheekbones of a 1950s matinee idol. His hair remains in the style that has served him for 70 years, a lopsided sweep. A prominent brow and hawkish stare give him a look of constant urgency, as though he is waiting for everyone to catch up. In Dublin, his outfit was academic-on-tour: jacket, woolly jumper and tie, one of a collection hand-painted by his wife, Lalla Ward, which depict penguins, fish, birds of prey.

At the end of the Trinity event, a crowd of about 40 audience members descended on to the stage, clutching books to be signed. Dawkins eventually retreated into the wings to avoid a crush. One young schoolteacher lingered in the hallway long after the rest of the audience had left, in the hope of shaking Dawkins’s hand. Earlier that day, Dawkins had expressed bewilderment at his own celebrity. “I find the epidemic of selfies disconcerting,” he said. “It’s always, ‘one quick photo.’ One quick. But it never is.” Though he is used to receiving a steady flow of letters from fans of The God Delusion and new converts to atheism, he does not perceive himself as a figurehead. “I don’t need to say if I think of myself as a leader,” he said a few weeks later. “I simply need to say the book has sold three million copies.”

Richard Dawkins speaks at the Cambridge Union debate about the role of religion in the 21st century, in 2013. Photograph: Jane Stockdale/Cambridge Union/EMPICS Entertainment

Dawkins turned 74 in March this year. To celebrate, he had dinner with Ward at Cherwell Boathouse, a smart restaurant overlooking the river in Oxford; the occasion was marred only slightly by a loud-voiced fellow diner, Dawkins recalled, “who quacked like Donald Duck”. An academic of his eminence could, by now, have eased into a distinguished late period: more books, the odd speech, master of an Oxford college, a gentle tending to his legacy. Though he is in a retrospective phase – one memoir published, a second on its way later this year – peaceful retreat from public life has not been the Dawkins way. “Some people might say why don’t you just get on with gardening,” he said. “I think [there’s a] passion for truth and a passion for justice that doesn’t allow me to do that.”

Instead, Dawkins remains indefatigably active. He rarely takes a holiday, but travels frequently to give talks – in the last four months he has been to Ireland, the Czech Republic, Bulgaria and Brazil. Though he says he prefers to speak about science, God inevitably looms. “I suppose some of what I do is an attempt to change people’s minds about religion,” he said, with some understatement, between events in Ireland. “And I do think that’s a politically important thing to be doing.” For Dawkins, who describes his own politics as “vaguely left”, this means a concern for the state of the world, and a desire, ultimately, to eradicate religion from society. In his mission, Dawkins is still, at heart, a teacher. “I would like to leave the world a better place,” he said. “I like to think my science books have had a positive educational effect, but I also want to leave the world a better place in influencing opinion in other fields where there is illogic, obscurantism, pretension.” Religious faith, for Dawkins, is above all a sign of faulty thinking, of ignorance; he wants to educate the ill-informed out of their mistakes. He sees religion, as he once put it on Twitter, as “an organised licence to be acceptably stupid”.

The two strands of Dawkins’s mission – promoting science, demolishing religion – are intended to be complementary. “If they are antagonistic to each other, that would be regrettable,” he said, “but I don’t see why they should be.” But antagonism is part of Dawkins’s daily life. “I suppose some of the passions that I show are more appropriate to a young man than somebody of my age.” Since his arrival on Twitter in 2008, his public pronouncements have become more combative – and, at times, flamboyantly irritable: “How dare you force your dopey unsubstantiated superstitions on innocent children too young to resist?,” he tweeted last June. “How DARE you?”

How dare you force your dopey unsubstantiated superstitions on innocent children too young to resist? How DARE you? — Richard Dawkins (@RichardDawkins) June 10, 2014

These days, Dawkins describes himself as “a communicator”. But depending on your point of view, he is also a hero, a heathen, or a liability. Many of his recent statements – on subjects ranging from the lack of Nobel prize-winning Muslim scientists to the “immorality” of failing to abort a foetus with Down’s syndrome – have sparked outraged responses (some of which Dawkins read aloud on a recent YouTube video, which perhaps won him back a few friends). For some, his controversial positions have started to undermine both his reputation as a scientist and his own anti-religious crusade. Friends who vigorously defend both his cause and his character worry that Dawkins might be at risk of self-sabotage. “He could be seriously damaging his long-term legacy,” the philosopher Daniel Dennett said of Dawkins’s public skirmishes. It is a legacy, Dennett believes, that should reflect the “masterpiece” that was The Selfish Gene and Dawkins’s major contribution to our understanding of life. As for Twitter: “I wish he wouldn’t do it,” Krauss said. “I told him that.”

Richard Dawkins reads outraged responses

The Dawkins mission has many components: in addition to his books and speeches, there is also the Richard Dawkins Foundation for Reason and Science (RDFRS), which he founded in 2006. The foundation is run by a team of three in Washington DC and supports multiple projects in the US, such as Openly Secular, a campaign to encourage atheists to proclaim their secularism, and the Teaching Institute for Evolutionary Science, which provides teachers with evolution-themed tools. Dawkins regularly goes on fundraising lecture tours, where his fame comes in useful. Tickets for a tour of the US in June – “an evening with Richard Dawkins”, in theatres in Portland, Oregon, Rochester, Minnesota and Boston – are on sale on the RDFRS website for $35. Access to a VIP reception beforehand is $250. Membership of the “Dawkins circle” costs from $1,000 to $9,999 a year, winning you discounts to the foundation’s online store, invitations to events with “RDFRS personalities” and, at its most expensive, two tickets for an “invitation-only” event with Dawkins himself. The fundraising is led by Robyn Blumner, the full time CEO of his foundation; Dawkins is her celebrity draw. “I’m totally hopeless at asking for money,” said Dawkins. “So I do work extremely hard at trying to be charming.”

In person, Dawkins subverts his reputation for stridency. He is reticent to the point of awkwardness, always scrupulously courteous. (Blumner described how every time they travelled together, he insisted on picking up her luggage from the carousel: “I call him my celebrity valet.”) His interests are broad: music, theatre, poetry. His favourite poets – Betjeman, AE Housman, Yeats – regularly make him cry. “I don’t cry over somebody dying,” he said. “But I cry over a beautifully turned phrase.” (His editor wanted to remove some of the frequent references to weeping from his second memoir, a view that perplexed him. “You might think, as I have a reputation for being callous and cold and unemotional, that to show a sentimental side would be no bad thing.”) At times, he can seem almost childlike, particularly in his enthusiasms. Recently, at home in Oxford, Dawkins gleefully showed off an iPad app that had been made from his children’s book, The Magic of Reality. As he launched a cannonball into space – an illustration of Newton’s explanation of how an object goes into orbit – a recording of his voice, resonantly theatrical, began to play: “Imagine a cannon …”

For Dawkins, the science has always come first; his atheism is simply a natural extension of a lifelong quest to do Darwin’s work on Earth. As for the suggestion his public interventions over the past few years have done more harm than good – both to himself and his cause: “That does worry me,” Dawkins conceded, and yet he cannot quite resist the urge to wade in. “I think there is a curious desire in humans, maybe not all humans but certainly in me, to put things right,” he said. “There’s a joke in the New Yorker or something like that, of a man at a computer. It’s obviously very late and his wife is begging him to come to bed. He’s saying, ‘I can’t come to bed. Somebody’s wrong on the internet.’”

Dawkins and Ward have lived in a large house in north Oxford since 1996. Ward, an actress famous for her role as the Time Lady Romana in Doctor Who, is his third wife – after Marian Stamp Dawkins, a fellow zoologist at Oxford University, and Eve Barham, the mother of his daughter Juliet. Over the years they have refurbished the house and it is now decorated with Ward’s paintings, leopard-print throws on the sofas and a menagerie of wooden carousel animals. The style is bohemian, eclectic, the taste of someone who prowls souks. Their two dogs, small fluffy creatures called Cuba (a havanese), and Tycho (a coton de Tulear named after a 16th-century Danish astronomer), have the air of pets who run the joint. “Silly dogs,” Dawkins said fondly as they yelped and jumped at his knees.

The dogs are generally more Ward’s concern than Dawkins’s; he is not hugely interested in animals. As a child, he preferred to read books while his nature-loving parents John and Jean were out spotting birds and plants. (Jean, aged 98, lives on the family farm in Chipping Norton, outside Oxford, where Dawkins visits her weekly.) Dawkins was born in Nairobi in 1941; until he was eight, the family lived in colonial east Africa where his father worked as an agricultural officer before joining the King’s African Rifles during the second world war. Even then, surrounded by nature at its most vivid, Dawkins remained uninspired. He remembers, as a young child, being taken in a safari car to watch a pride of lions gnawing at a carcass. While the rest of the group stared in fascination, he stayed on the floor playing with his toy cars. He does, however, know every class and order of the animal kingdom, a product of the classical zoological education he received as an undergraduate at Oxford. If he has trouble sleeping, he mentally scrolls through the alphabet and assigns mammals to letters.

As a postgraduate, Dawkins excelled at the early stages of the research process, mulling theoretical questions and coming up with hypotheses. But he lacked patience with the laborious hours of data collection or methodical lab work. His interest in zoology was philosophical, not naturalistic: animals were simply the language he’d chosen to learn in order to interpret the world.

On a recent spring afternoon, sitting in his back garden, he explained the evolution of social insects by imitating an ant whose sole function was to guard the entrance hole to a giant bamboo stick in which the ant colony lived. The ant had an elongated head that it used like a door to block the hole and prevent the entrance of intruders. Dawkins hunched in his chair and stuck his head forward, then jerked it back, blocking and unblocking the hole. The performance was strangely captivating, but the ant was simply a means to explain the social behaviour of insects. “Everybody knew that if Richard asked you why you were interested in zoology,” said Kate Lessells, a former student of Dawkins in the 1970s and now a field biologist, “‘Because I like animals,’ was not an answer that was going to go down well.”

Instead, his students knew him as “the computer man”: a pioneer in the developing strand of biology based on the mathematical modelling of animal behaviour. He would regularly stay up all night writing code on the sole computer in the zoology department, an Elliot 803 – at the time a relatively compact machine, now the kind of elaborate object kept for historical interest by the Science Museum. When it broke down, the joke among undergraduates at the time was that Dawkins had been trying to “wire himself into it”.

The language of technology was ubiquitous in The Selfish Gene. Organisms were “survival machines”, bodies “lumbering robots”, nothing more than vehicles for genes. To its critics, the book was an assault on human values: it seemed to suggest, in that stark title alone, that we existed simply to pass on our individual genes and cared nothing for each other, the common good, community. To Dawkins, this was a basic misreading of his argument. Biological nature might be hardwired in its self-interest, but we don’t have to obey its laws. “Let us try to teach generosity and altruism, because we are born selfish,” he wrote in the book’s first chapter. (Looking back now, Dawkins wonders if he should have called the book “The Immortal Gene”, in order to avoid the misunderstanding.) In his next book, The Extended Phenotype (1982), which he regards as his most significant contribution to science, Dawkins explained that he wrote The Selfish Gene while on sabbatical, after returning, high on ideas, from a conference on artificial intelligence. “I genuinely and innocently in my enthusiasm forgot that robots are popularly supposed to be inflexible idiots,” he wrote.

Dawkins has never lost his affection for technology. He is an Apple devotee, and an early adopter; he owns the 47th Tesla electric car to be sold in Britain. In his spare time, he plays the EWI, an electronic musical instrument similar to a clarinet. Recently, he’s been resurrecting a program that he wrote in the 1980s to illustrate the process of evolution, called Blind Watchmaker. It had originally been written in Pascal, an obsolete programming language. A few years ago, Dawkins put a plea on his website for help updating it. A freelance programmer called Alan Canon, based in Louisville, Kentucky, spent months on the project – often working through the night, grateful for the chance to collaborate with his “intellectual hero”, as he put it. Canon was brought up in a fundamentalist Christian household, shed his faith, and later became a dedicated Dawkins fan. (“He says one true thing after another,” Canon said.) As he worked on the programme, the two men exchanged emails daily and Canon came to the conclusion that Dawkins was “a born computer programmer”.

Sitting at the computer in his study, Dawkins gave a demonstration of Blind Watchmaker. First, he clicked on the monochrome image of a tree in the centre of his screen and a handful of slightly different trees appeared – its offspring. He then clicked on one of these surrounding trees and the screen refreshed so that the chosen tree was now central and in turn encircled by a new generation. As he continued to select which new tree to breed from, it was possible to see gradual changes taking place depending on which “child” he had chosen.

The first time Dawkins tested his creation back in the 1980s he saw, after numerous selections, images of entirely new creatures emerge, apparently distant from the original tree and yet its logical descendants: spiders, fish, a fox. He was the breeder; the process, by artificial selection, was evolution. “I distinctly heard the triumphal opening chords of Also sprach Zarathustra – the 2001 theme – in my mind,” he wrote in The Blind Watchmaker (1986). Even now, playing a game he invented 30 years ago, Dawkins became excitable as he unleashed generation after generation, click after click. “Look at these, you see?” he said, pointing at the morphing shapes. “Look how quickly you can evolve!”

On a walk round Oxford one afternoon in March, Dawkins showed off some old haunts: a court for “real” tennis (the Tudor form of the game) where he’d played a few times, and his undergraduate room at Balliol College. Dawkins remembered little in the way of university antics: he was “mousey” as a student, didn’t lose his virginity until the age of 22, and was, he said, “pusillanimous to a fault” with women.

Most days he cycles in for lunch at New College, where he has been a fellow since 1970. He has no duties in college, and stopped teaching in 1995 when he became the first Charles Simonyi professor for the public understanding of science, but he likes to maintain the connection. He’ll even say grace at dinner, if required: “I have no objection to uttering meaningless statements,” he said, quoting the philosopher AJ Ayer.

In conversation, Dawkins is most comfortable in the mode of an Oxbridge tutorial – as a professor conducting an in-depth discussion with a student. His own students still remember the experience very clearly. “He’d say, ‘I’m going to just focus on what you say and take it very seriously,’” recalled Alan Grafen, now a professor of zoology at Oxford. Dawkins’s strategy as a teacher remains his tactic in public argument: to challenge your logic, or expose what he regards as your lack of it.

In all his books, logic has been both subject and mode of thought. The Blind Watchmaker, Climbing Mount Improbable (1996), The God Delusion and The Greatest Show on Earth (2009) were all battles against the perceived irrationality of creationist thinking. It was not enough to say that he did not approve of religion or its role in society; he needed to prove its impossibility. (The God Delusion contains a 42-page chapter devoted to this enterprise, entitled, “Why There Is Almost Certainly No God”.)

Sitting in the Enthoven room in New College, Dawkins characterised his own mode of argument – and the controversies that invariably ensue – as guided by the techniques of moral philosophy: “Moral philosophers say things like, ‘What is actually wrong with cannibalism?’ There are two ways of responding to that: one is to shrink back in horror and say, ‘Cannibalism! Cannibalism! We can’t talk about cannibalism!’ The other is to say, ‘Well, actually, what is wrong with cannibalism?’ Then you work it out and you tease it out and you decide yes, actually, cannibalism is wrong, but for the following reasons. So I’d like to think that my moral values at least partly come from reasoning. Trying to suppress the gut reaction as much as possible.”

For a point to be of any worth to Dawkins, he demands both logic and evidence – a standard he applies to even the most personal of experiences. As a child, he experienced sexual abuse: a teacher at his junior school, Chafyn Grove, pulled Dawkins on to his lap and put his hand inside his shorts; at his senior school, Oundle, he fended off older boys who tried to climb into his bed at night. Dawkins has never made much of his experiences at school, he said, because he is certain it had no lasting effect; he has argued – to much outrage, naturally – that being raised in a fundamentalist religious household might be worse than suffering sexual abuse. To make a fuss about his own case, he believes, would be belittling to children whose lives had been more obviously tainted by similar treatment and it would also be irrational, unsupported by empirical evidence: “I’ve never had dreams, never had nightmares.”

The scientific method, for Dawkins, is not merely essential to understanding the physical world; it can be deployed to help answer moral questions as well. “Human society, human love, human hate, art, music, poetry – these are all things which are the products of human brains, and brains are the products of ultimately scientifically explicable phenomena. But not in practice explicable, because it’s too difficult, it’s too complicated.” There is still room in Dawkins’s worldview for mystery – about the nature of human consciousness, for example – but that mystery is neither supernatural nor ultimately inexplicable.

The author Philip Pullman, one of Dawkins’s friends, recalled a discussion the two once had about what you might tell a terminally ill child about death. Dawkins “was very unwilling, or seemed to be, to say that it would be OK at that point to tell a fairytale about heaven,” Pullman said. “He’s a man of immense principle; he’s sea-green incorruptible.”

In recent years, the following sequence of events has become something of an online soap, regular and predictable: Dawkins tweets, is criticised for being deeply offensive, and then writes a long article to explain what he actually meant, which usually is not too far from what he said in the first place, but expressed with slightly more nuance. Since Dawkins joined Twitter seven years ago, he has amassed more than a million followers. He tweets assiduously, attracted by the medium’s limitations: “I’m sort of mildly intrigued by the art form of précising something into 140 characters; it’s not an easy thing to do. And there’s a certain satisfaction in the skill of doing it.”

His efforts are not always appreciated. On occasion, his online utterances descend into farce, as when he took to Twitter in 2013 to rage over having an item confiscated by airport security, declaring: “Bin Laden has won, in airports of the world every day. I had a little jar of honey, now thrown away by rule-bound dundridges. STUPID waste.” Dawkins responded to the ensuing mockery with a frustrated attempt at clarification: “Do you idiots seriously think I give a damn about my stupid honey? It’s the PRINCIPLE I care about. Get it? Principle, not honey, principle.” (As if in tribute to a concept he invented – the meme, first introduced in The Selfish Gene – Dawkins’s own tweets have inspired endless online parodies: a year after the unfortunate airport episode, someone wished him a “happy honeyversary”.) Even on more serious topics, Dawkins cannot quite fathom how often he finds himself at the centre of online firestorms. “I do seem to be horribly susceptible to being misunderstood,” he said.

Bin Laden has won, in airports of the world every day. I had a little jar of honey, now thrown away by rule-bound dundridges. STUPID waste. — Richard Dawkins (@RichardDawkins) November 3, 2013

“Quite a lot of what I do on Twitter is try to raise a discussion point,” he said. “It’s as though I was doing a seminar with students and said, ‘Here’s an interesting thought, X. What do you think about X?’” He is then mystified when his hypothesis is met by a chorus of criticism and abuse. “Very often I’m not making a point, but asking a question.” Sometimes his questions seem genuinely curious: “Whistling requires precise tongue positioning, like finger on violin string. Yet most can whistle tunes sans training. Interesting?” But often they are more rhetorical: “Truly? Is Sweden such a fatuously ridiculous country, bending over backwards to accommodate religious idiocy?”

Last July, Dawkins wrote, in 136 quickly infamous characters, “Date rape is bad. Stranger rape at knifepoint is worse. If you think that’s an endorsement of date rape, go away and learn how to think.” For Dawkins, this was simply the illustration of a basic point of logic; on the other hand, he was using a highly sensitive crime as an example. “If I used another example it would have been obvious,” Dawkins said, by way of explanation. “The point is there are people who seriously refuse to admit that some rapes are worse than others.” Isn’t that a judgment to be made by the person who’s experienced it? “Exactly, which is why I said date rape may be worse than stranger rape. I said that. It’s up to the victim to decide … But it’s absurd for the thought police to come along and say that it is forbidden to allow a woman to rank some rapes as worse than others … This is a logical point, and there are people who say that emotion trumps logic.” For Dawkins, the idea that someone could understand his argument and still disagree with him was bewildering. “There must be something wrong with how I’m expressing it,” he said. In the presence of his logic, there is no room for an alternative view.

Date rape is bad. Stranger rape at knifepoint is worse. If you think that's an endorsement of date rape, go away and learn how to think. — Richard Dawkins (@RichardDawkins) July 29, 2014

Dawkins’s devotion to rational thought doesn’t preclude emotion, however. He once tweeted: “Theists: you get comfort in the imaginary embrace of an imaginary friend? Try real warm embrace of a real warm friend. That’s comfort.” (One of his numerous online tormentors quickly replied: “I think Richard Dawkins got laid last night.”) Asked for a definition of love one recent afternoon, Dawkins gave a precise Darwinian explanation of sexual love, parental love and agape – the love of humankind – and then looked into the middle distance and said: “I feel it deeply.” But emotion, as he sees it, has no place in argument. “More than anyone else I know, he has a hard time understanding people’s irrationality,” Krauss said. “It’s a personality thing.” Dawkins’s self-analysis was more concise: “I get impatient.”

After he was confirmed, aged 13, Dawkins became passionately religious, praying every night, curled up in a foetal position on his bed in his “own little corner with God”, as he wrote in his first memoir. Gradually, he distanced himself from Christianity, but still believed in a divine creator, helped by his deep love of Elvis. (The clincher was “I Believe”, from the album Peace in the Valley.) Finally, a school friend who had done the reading persuaded him of Darwin’s theory, and Dawkins, aged 17, became an atheist. The campaign had begun: from that moment, he refused to kneel in chapel.

For his part, Dawkins has always maintained that he is not in the business of conversion. “I certainly don’t want to do anything remotely approaching indoctrination,” he said. That, along with the mass following, fundraising, YouTube videos and children’s books, would perhaps be borrowing too much from religion’s toolbox. Dawkins has taken shots at all major religions, but Islam has become the particular focus of his recent ire. “I have an anxiety about beheadings, stoning, setting people on fire,” he said. “No other group in the world at the moment does that. Isn’t that clear?” The emergence of the New Atheists was not accidental: their books were published shortly after 9/11, and Islamic fundamentalism remains one of their major preoccupations. After the Charlie Hebdo attacks in Paris in January this year, Dawkins took to Twitter (“No, all religions are NOT equally violent”) and blamed the actions of the terrorists exclusively on their faith, dismissing any socio-political theorising as to why two brothers might shoot 12 people at a satirical magazine.

Dawkins has no time for the concept of Islamophobia – he calls it a “nonsense word” – and strongly rejects the argument that his criticism of Islam appears at times to have a racial inflection: “I detest any tendency to treat a person on the basis of a group to which they belong.” The notion that Muslims might see their faith as an inseparable part of their identity is absurd to him: “That’s their problem and they need to grow up.”

After a series of rows following similar statements (“Of course you can have an opinion about Islam without having read Qu’ran. You don’t have to read Mein Kampf to have an opinion about nazism”), Dawkins has come to believe he is targeted by hysterical, politically correct critics, who refuse to see he is attacking a religion, not a race. But his public praise for the work of professional anti-Islam controversialists, such as the far-right Dutch politician Geert Wilders, have not helped his case. He has also attracted some unsavoury cheerleaders, such as Tommy Robinson, the former head of the English Defence League, who supported Dawkins’s statement that Islam was “one of the great evils in the world”. On hearing of Robinson’s endorsement, Dawkins said: “That’s unfortunate, I didn’t know that. It’s an important point of logic, again, that if you agree with so and so about x it doesn’t mean you agree with them about y, z, a, b, c.”

Of course you can have an opinion about Islam without having read Qur'an. You don't have to read Mein Kampf to have an opinion about nazism. — Richard Dawkins (@RichardDawkins) March 25, 2013

The Muslim writer and thinker Ziauddin Sardar, who has debated Dawkins in the past, argued that Dawkins and his fellow New Atheists had dangerously stoked anti-Islamic sentiment in the west. “He may be worried about Islam, but he’s not nearly as worried about Islam as I am,” Sardar said. Dawkins’s generalising rhetoric about Islam was “dehumanising a community,” Sardar added, “a human community with all shades of opinion”. Dawkins might claim he only attacks the faith, not its individual believers, but in Sardar’s view his depiction of that faith denies its social and political complexity. “What he is doing,” Sardar said, “is creating a world that is more belligerent than the one we find ourselves in.” For someone like Sardar, who described himself as trying to change his faith from within, Dawkins is “undermining the kind of work that people like me do”.

It is not just the religious who voice concern: Dawkins has begun to alienate those on his own side. Prominent non-believers, such as the philosopher John Gray, have criticised the literal-minded absolutism and intellectual superiority that Dawkins exhibits in his atheism: “Dawkins imagines an atheist is bound to be an enemy of religion,” wrote Gray in a recent review. “But there is no necessary connection between atheism and hostility to religion.” In Gray’s view, Dawkins’s dedication to science amounts to an “unquestioned view of the world” excluding, and insulting, any alternative interpretation.

Some former intellectual allies, such as the Darwinian philosopher Michael Ruse – who lives and works in the US, where he has fought legal battles to ban the teaching of creationism in schools – see Dawkins’s antagonism as more likely to alienate than convert. To Ruse, Dawkins shows no interest in engaging with his opponents in order to defeat their arguments – “hammering Islam,” for example, “without any real understanding”. “His treatment of philosophical ideas in The God Delusion is frequently funny and certainly good journalism,” Ruse said, “but to put it politely it is deeply uninformed.”

Perhaps the greatest source of disquiet within the atheist movement – particularly in the US, where the movement, under the broad banner of “skepticism”, is more active and organised – is among feminists. Greta Christina, an American feminist and atheist blogger, first met Dawkins at an event in 2009. It was a fantasy made real. “He was the reason I started calling myself an atheist … [meeting him] was one of the proudest moments of my life.” Then, in 2011, Dawkins waded into a comment thread under a blogpost about a discussion of sexual harassment that had recently taken place at a skeptics’ conference in the US: “Dear Muslima,” Dawkins wrote to an imagined Muslim woman, “Stop whining, will you. Yes, yes, I know you had your genitals mutilated with a razor blade, and ... yawn … don’t tell me yet again, I know you aren’t allowed to drive a car … But stop whining, will you. Think of the suffering your poor American sisters have to put up with.”

The attempt at satire went down badly: Dawkins appeared to be dismissing any concerns about sexual harassment (“He spoke some words to her. Just words,”) and doing so by ranking the experiences of women. He later apologised, but it marked, for Christina, a “disappointing and discouraging” turn for Dawkins, who had become, in her eyes, “so troubling, in such serious ways, and in particular so stubbornly troubling”.

Dawkins has always called himself a “passionate” feminist. As a fellow at New College, he agitated to allow women to be admitted, a change that occurred in 1979. “I show my feminism very largely in the Islamic context,” he said. “Because if women are having a hard time anywhere in the world, it’s there … I get impatient with American feminists who are so obsessed with being looked at inappropriately over the water cooler at work or whatever it is, that they forget that there are women being literally stoned to death for the crime of being raped.”

His position has been interpreted in unfortunate ways by some of his followers. “Because he’s such a hero in the movement,” the American feminist Ophelia Benson said, “that gave a green light to an awful lot of people in the movement who thought it was okay to harass [feminists].” In recent years, online sceptic forums have been deluged with bilious anti-feminist posts and crude photoshopped images of women.

In an attempt to quell the increasingly unpleasant tone of discussion, Dawkins released a statement last August, jointly written with Benson, calling for an end to the online abuse. Dawkins added a personal footnote: “I’m told that some people think I tacitly endorse such things even if I don’t indulge in them. Needless to say, I’m horrified by that suggestion. Any person who tries to intimidate members of our community with threats or harassment is in no way my ally and is only weakening the atheist movement.”

A few weeks later he was back on Twitter writing comments about how a drunk woman’s evidence was unreliable in a rape trial. Why? “Because I not only care passionately about truth, I care passionately about justice.” (Should it not worry him more that such a tiny proportion of rape cases make it to court at all? “Oh absolutely … I care very passionately about that, of course I do.”) Benson, who had encouraged Dawkins to write the statement in the first place, looked on in despair. “No, no, Richard,” she remembered thinking. “That was not the idea.”

* * *

Dawkins is mostly unconcerned by the possible damage he has inflicted on his reputation, but he has moments of self-doubt. “I genuinely don’t know whether I’m going about it the right way,” he said, in the half-resigned tone of someone who probably couldn’t go about it any other way. Recently, there have been some signs of reputational management – in a video interview on his “Vision of Life” for the Edge website, he discussed Darwinian natural selection without once mentioning his anti-religious campaigning. His memoirs, he pointed out, bypassed his various online wrangles entirely. In conversation, Dawkins seemed concerned that an article about him would draw disproportionately on his Twitter feed – in his eyes, an insignificant late chapter in the context of his whole career. “I’m a scientist,” he said, as if this fact might be forgotten.

Richard Dawkins on his “Vision of Life”

“Ultimately, will his net impact be positive?” Krauss asked. “I think the answer’s yes. For all the intelligentsia and all the people who are offended, I see a much larger audience that I hadn’t appreciated for whom these issues are brand new.” He meant people like Arori Newton, a 24-year-old Kenyan lawyer who thanked Dawkins for his books on Twitter one afternoon. The God Delusion, Newton said in an email, “changed my life completely. It occurred to me, for the first time, that I was a Christian simply because I had been born into a Christian family, not because I had made a conscious choice.” Now Newton was buying copies for all his friends.

Perhaps a culture needs someone like Dawkins: his unswerving commitment to a cause, his enormous capacity to inflame and offend. Daniel Dennett, a keen sailor, described Dawkins as his “sacrificial anode” – the hunk of zinc you bolt to the propeller shaft on a boat to protect the propeller from being eroded by seawater. The zinc is gradually worn away while the propeller remains unscathed. “In life you always want somebody out to the left of you to take the heat.”

Dawkins both takes and emits great heat, but there’s no sign of imminent disintegration. “I’d like to go on living for a while longer,” he said recently. Death itself didn’t worry him, though he expressed frustration at the thought of all the scientific and technological progress he would miss. His funeral was semi-planned. There will be no prayers, obviously, but the ceremony will include the first sentences of his 1998 book, Unweaving the Rainbow: “We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born”. Also, the Elephant March from the opera Aida, “It’s triumphal,” Dawkins said. “Going out on a high.”

• Follow the Long Read on Twitter: @gdnlongread