"My dad was a slightly stricter version of Richard Dawkins," says Alain de Botton. "The worldview was that there are idiots out there who believe in Santa Claus and fairies and magic and elves and we're not joining that nonsense." In his new book, Religion for Atheists, he recalls his father reducing his sister Miel to tears by "trying to dislodge her modestly held notion that a reclusive god might dwell somewhere in the universe. She was eight at the time." It's one of few passages in his unremittingly mellifluous and genteel oeuvre that sticks out with something like anger.

Before the interview, his publicists warned that De Botton didn't want to talk about Gilbert de Botton, Egyptian-born secular Jew and multimillionaire banker. He was especially keen not to discuss his father's business dealings and the repeated suggestion that his literary career was bankrolled with daddy's money.

But asking about De Botton's father is irresistible because Religion for Atheists is, he readily concedes, an oedipal book. "I'm rebelling," he says. "I'm trying to find my way back to the babies that have been thrown out with the bathwater." He's elsewhere described his father as "a cruel tyrant as a domestic figure, hugely overbearing". He was also surely crushingly impressive – the former head of Rothschild Bank who established Global Asset Management in 1983 with £1m capital and sold it to UBS in 1999 for £420m, a collector of late Picassos, the austere figure depicted in portraits by both Lucian Freud and Francis Bacon and an atheist who thrived without religion's crutch.

"He was extreme. I think it was a generational thing." And yet Gilbert, who died in 2000, now lies beneath a Hebrew headstone in a Jewish cemetery in Willesden, north-west London because, as his son writes pointedly, "he had, intriguingly, omitted to make more secular arrangements". Disappointingly, Alain doesn't explore in book or interview what intrigued him about that omission.

Instead, he connects his father's militant atheism to the affliction that he reckons made Dawkins and Christopher Hitchens so caustic in their bestselling attacks on religion. "I've got a generational theory about this. Particularly if you're a man over 55 or so, perhaps something bad happened to you at the hands of religion – you came across a corrupt priest, you were bored at school, your parents forced it down your throat. Few of the younger generation feel that way. By the time I came around – I'm 42 – religion was a joke.

"I don't think I would have written this book if I'd grown up in Saudi Arabia as a woman. It's a European book in the sense that we're living in a society where religion is on the back foot. It rarely intruded on my life."

This isn't quite true. In his mid 20s, De Botton had a crisis of faithlessness when exposed to Bach's cantatas, Bellini's Madonnas and Zen architecture. What was the crisis about? "It was guilt about my father. I was disturbed by the intensity of the feeling. Bach was moving, but not just because of music but because this guy was talking in a tremulous voice about death. Secular culture tells us to respect Bach, but it doesn't tell us that we're going to be moved. I felt like I might go to the other side."

He didn't. Rather, in Religion for Atheists, he writes as a non-believer cherry-picking the world's religions. "I guess my insight was: 'What is there here that's useful, that we can steal?'" He admires 18th-century Jesuits. "They wanted to put a Jesuit priest into every aristocratic family in Europe because they'd get to eat with the family and teach the children. That's a fantastic idea." It's tempting to think of De Botton as a latter-day Jesuit seeking to install his books in every home in order to make us, even if faithless, good. "Secular thinkers have a separation between thinking and doing. They don't have a grasp of the balance sheet. The doers are selling us potted plants and pizzas while the thinkers are a little bit unworldly. Religions both think and do."

He, similarly, wants to put his ideas into practice. In 2008, he established the School of Life, a former Bloomsbury shop with books on the ground floor and a salon downstairs where he and his fellow teachers teach "ideas to live by". He's also creative director of Living Architecture, aiming to put into practice his neo-Platonist idea that beautiful buildings might make us good. He recently commissioned the Pritzker prize-winning Swiss architect Peter Zumthor to build a secular retreat. "The idea is to create the most useful aspects of a monastery without the ideological aspects of monasticism."

In this, he follows 19th-century French sociologist Auguste Comte, whose Religion of Humanity plundered religious ideas to improve a godless people. De Botton shows me a photo on his phone of a Comtean temple in Porto Alegre, Brazil. "I'm fascinated by Comte's clear-eyed analysis of what was wrong with modern society, which is that you've got industrial capitalism on one side and romantic love on the other. Those, along with non-instrumental art, are supposed to get you through the day?

"But the whole business of Comte as supreme father and his girlfiend as supreme mother is obviously nuts." Nuts, but suggestive: I imagine a berobed De Botton as supreme father of his 21st-century secular religion, with wife Charlotte or stepmum Janet as supreme mother, and sons Saul and Samuel as choirboys improving us with Bach.

We're sitting in his publishers' offices overlooking the Thames. Downstream is a secular institution he believes needs a religious-inflected makeover. Imagine, he writes, if museums really lived up to their billing as secular society's churches and devoted themselves to making us good, happy and wise (rather than, as he suggests, baffled, tired and desperate for coffee). On page 245 he produces a floor plan of Tate Modern to show us what he means. On the seventh floor is the self-knowledge gallery, beneath it galleries of love, fear, compassion and suffering. Each displays art directed at making us feel a certain way – just as Giotto's frescoes of the cardinal virtues and vices in Padua's Scrovegni chapel were aimed at doing.

One wonders what Gilbert de Botton, leading art patron, would think of this curatorial revolution, since one of Tate Modern's galleries currently bears his name. In terms of the book's oedipal struggle, this suggestion reads as typically urbane symbolic castration.

Can't society get to where De Botton wants it to go without plundering religion? He argues not: "Politicians want people to be nice neighbours but the tools at their disposal are just the tools of modern liberal society, which are nothing." What about the Tories' notion of a big society? "They're sitting in the cockpit and they haven't got the buttons."

Religions, he thinks, have the buttons and know how to use them. His book considers the Catholic mass, early Christianitiy's ritual of agape or love feasts, and Jewish Passover rituals to explore how religions encouraged us to overcome fear of strangers and create communities. He then tentatively imagines a so-called "agape restaurant" where, instead of dining with like-minded friends, you would be invited to eat with strangers. It would be the antithesis of Facebook. "Social media has lots of benefits but compared to Christianity it tends to group people by interests. Religion puts you with people who have nothing in common except that you're human." It might be a welcome challenge, he suggests. "I think that's what we need at a societal level – hosts who are able to produce the benevolence, charity, curiosity and goodwill that are in all of us but we can't let out."

His strong point is that religion never lost faith in using culture to improve vulnerable, childlike souls. It understands, he contends, human frailties and how to work on them better than godless polities. He's at his most bracing when he proposes wholesale educational reform, suggesting that universities' humanities departments should be overhauled to do what John Stuart Mill and Matthew Arnold hoped for them, namely to instil wisdom. He recommends: "Anna Karenina and Madame Bovary would thus be assigned in a course on understanding the tensions in marriage instead of in one focused on narrative trends in 19th-century fiction, just as the recommendations of Epicurus and Seneca would appear in the syllabus for a course about dying."

Doesn't instrumentalising culture thus involve traducing it? "Religion is very unembarrassed about this – culture should have a purpose. I agree with it. Arnold said that culture should be a salve for society. Then in the late 19th century you get the late romantics, Oscar Wilde and then the modernists, Joyce and TS Eliot, who say 'No – art is a privileged sphere and shouldn't have a purpose'. But I have a practical attitude: I'll use a particular poet or particular music or art to get me through something. I would be even more of a basket case without culture. "

De Botton's scepticism about education is born of his own experience of it. Born in Zurich, he was sent to England aged eight by his father to study at the Dragon School in Oxford. After failing to get into Eton, he attended Harrow. After a double first in history at Cambridge, he did a master's in philosophy at London, began a PhD in French philosophy, but gave up. Why? "I had a long night of the soul. I wanted to be an academic but I discovered that the whole thing is set up in the most devilish way to kill that enthusiasm.

"I love the idea of a university as away from capitalist values, where people can do things that don't immediately have to pay their way. It's like a monastery in a way, and that beautiful refuge has been destroyed by dogma about what this stuff is for." Especially in academic philosophy? "The arrogance that says analysing the relationship between reasons and causes is more important than writing a philosophy of shyness or sadness or friendship drives me nuts. I can't accept that.

"I had a line in the book I cut that said 'The nirvana would be if the questions raised by Oprah Winfrey would be answered by the faculty at Harvard.' The questions she asks are the most central – how do we live with other people, how do we cope with our ambitions, how do we survive as a society – though she fails to answer them with anything like seriousness."

He thus suggests he and Oprah, unlike our philosophy departments, have a surer grasp on society's anxieties. "I once very politely raised the thought that one reason philosophy departments have been cut is the fault of philosophers. The answer always comes back: 'The point of philosophy is to ask questions, not to give answers.' I can't help but think 'No. It can't be!' Imagine if you applied that question to other areas – is the purpose of rocket science to ask questions about rockets?"

We need, he insists, answers to Oprah-like questions now more than ever. "We're quite adrift. Civilisation should be about the transmission of the best ideas and we don't seem to believe in transmission. We've no effective mechanism."

After abandoning his doctorate, he resolved to answer philosophy's big questions outside academia through the mechanism of popularising books. He wrote the novels Kiss and Tell, Essays in Love and The Romantic Movement in which characters appealed to Wittgenstein, Aristotle and Montaigne for romantic guidance, before settling into what he calls "my schtick". That schtick first appeared in How Proust Can Change Your Life (1997), where he strip mined the Frenchman's great novel to produce a self-help manual that became a global bestseller (thanks in part to John Updike's New Yorker review describing it as "dazzling"). But the idea that A la recherche du temps perdu could be distilled scandalised some Proustians.

After instrumentalising Proust, he ransacked philosophy for soothing thoughts. Reviewing The Consolations of Philosophy (2000) for the Guardian 11 years ago, I noted that while Schopenhauer's The World as Will and Representation sold 230 copies on publication in 1819, De Botton's relatively negligible book, with its marketing hoopla and attendant TV series, would sell many, many more. How, I howled, were we to be consoled for that?

But that was to underrate De Botton's schtick: his questions are regularly cannily and, in business terms, astutely attuned to our zeitgeist. The Art of Travel (2002), Status Anxiety (2004) and The Architecture of Happiness (2006) tackle Oprah-like questions: why does travel so rarely match up to our daydreams? What makes people judge me as a success or failure? Why don't architects design buildings that make us happy?

His schtick has savage detractors. Charlie Brooker wrote in the Guardian that De Botton was "a slapheaded, ruby-lipped pop philosopher who's forged a lucrative career stating the bleeding obvious". The Times's Sathnam Sanghera wrote of The Pleasures and Sorrows of Work (2009): "When people are losing their jobs, struggling with mortgages, swapping Waitrose for Aldi, the last thing they need is someone who has never really had to work (De Botton's late father was a Swiss financier who apparently left him a trust fund of £200m), pretentiously encouraging us to ask such questions as: 'What do I get from work apart from money?'; 'What makes work pleasurable?'; 'Why do we daily exhaust ourselves?'"

De Botton snapped. He wrote to Sanghera: "I find it utterly disgraceful that you rake up as a truth a piece of utterly unresearched gossip about me being worth £200m. Do you really want to know 'how much I am worth?' OK, well, as you asked, as of this morning, I have £7.45m in my Cahoot interest account. This represents the fruit of 15 years of hard labour selling books which you might find (hilariously) to be utterly 'pretentious', but which clearly other people don't always find repulsive."

That was mild compared to what he wrote to Caleb Crain for his New York Times mauling of the same book. "You have now killed my book in the United States … I will hate you till the day I die and wish you nothing but ill will in every career move you make."

It's hard to believe the sanguine, incessantly polite De Botton wrote these words. But he did. "My response was ridiculous. It was silly. It was a cry of pain." If only he'd taken to heart what he wrote in The Consolations of Philosophy about Seneca's counsel on the futility of anger and the importance of stoic self-possession. But his response to that failure shows he has learned something from religion, especially its conviction that we are fallible and childlike: "As we know," he says, "none of us is mature, particularly me."