Richard Dawkins has had a wonderful life. He’s been happy in his scientific work on evolution, blessed (if that’s a permissible word) by smooth good looks and contented in his (third) marriage. He’s been given joy by his collaborators and colleagues and taken pleasure in poetry and music, even religious music. He’s collected bouquets of honorary degrees, including one from Valencia, which, he tells us, gave special delight because it came with a “tasselled lampshade” cap, and he has both an asteroid and a genus of fish named after him. Oxford college life has been sweet, and he’s been fulfilled by his role as public intellectual, defender of scientific reason, secular saint and hammer of the godly, switching from the zoology department in 1995 to a new endowed chair which allowed him to work full-time on “the public understanding of science”. His books – from The Selfish Gene (1976), River Out of Eden (1995) and The God Delusion (2006) to the first volume of his autobiography An Appetite for Wonder (2013) – have been successful, well-received, and, as Dawkins proudly notes, are all still in print. They have sold extraordinarily well – more than 3m copies of The God Delusion alone – making their author comfortably off as well as famous. According to the notions he coined, both selfish genes and memes want to make lots of copies of themselves, but there must be some genes or memes that haven’t been as successful as Dawkins himself.

Where once the humanists and philosophers were cocks of the cultural walk, now Dawkins can claim without argument that there are “deep philosophical questions that only science can answer”. There are no mysteries, just as-yet-unsolved scientific problems: “Life is just bytes and bytes and bytes of digital information.” The culture wars are over; science has won and Dawkins is confident that he has played a non-trivial role in that victory. Surveying the enormous change in the public prestige of science since CP Snow’s The Two Cultures (1959), he takes satisfaction that his books have been “among those that changed the cultural landscape”. Snow complained that, for some unfathomable reason, scientists were not counted as “intellectuals”. That has all changed. In 2013, readers of Prospect magazine voted Dawkins the world’s “top thinker”.

The enemies Dawkins has made are, in the main, the enemies he anticipated. As an atheist, he is a vigorous critic of the creationists, their religious fellow-travellers, the postmodernists, relativists and assorted “enemies of reason”. And as a participant in the scientific cage-fighting that is modern evolutionary theory, Dawkins has one of the sharpest tongues in modern culture. Take this assessment of religious people, for example: “faith seems ... to qualify as a kind of mental illness” and “what has ‘theology’ ever said that is of the smallest use to anybody?”. Or this criticism of a book by his scientific opponent, Harvard’s EO Wilson: “an act of wanton arrogance” and, with a nod to Dorothy Parker, “this is not a book to be tossed lightly aside. It should be thrown with great force.” As has been said of the traditional English gentleman, Dawkins has never been unintentionally rude; and his snarling is unremitting. Writing in the Observer some years ago, Robin McKie described him as “the Dirty Harry of science”, and a Spectator review defined what it means to be “Dawkinised”: “Not just to be dressed down or duffed up, it is to be squelched, pulverised, annihilated, rendered into suitably primordial paste.”

Commentators disagree about whether there is a mismatch between the public rage and what Dawkins is like when he is not, so to speak, “miked up”. But he tells us a bit about himself here and elsewhere, and what he sees when he looks in the mirror is the face of a man who is considerate, pleasant and even tolerant: “I’ve never been the sort of firebrand that I’ve been made out to be. I’m actually quite a mild person.” He thinks of himself as driven not by fulminating hostility to religion – that’s actually incidental, he insists – but by enchantment with scientific rationality and the beauty of knowledge. He wants us all to share in the certainty that scientific reason offers. Why would anyone choose religious hocus-pocus over that? Of course, spades ought to be called spades, and opponents of evolution must be either “ignorant, stupid, insane or wicked”. But there has never been anything personal in his opposition to religion or to scientific error. It’s no crime to be stupid; you’re just in need of Dawkinsian correction: read the books; see the light. When he was subwarden of New College, Oxford, he had no problem saying grace – this was, after all, not error, just meaningless rhetoric. He got on well with the college chaplain, who seemed in many ways a decent sort, and he enjoyed all his meetings with the former archbishop of Canterbury, Rowan Williams, “one of the nicest men I’ve ever met”.

The first instalment of Dawkins’s memoirs had the usual chronological structure for this sort of thing: childhood, education, dawning vocation, first jobs, finishing up with the book, The Selfish Gene, that made his reputation both as a significant evolutionary theorist and as a major contributor to the public understanding of science. Brief Candle takes up the story from around the time that An Appetite for Wonder left off, but it doesn’t aim to have a storyline. It’s a loose and multiply digressive collection of reminiscences, anecdotes, addenda, quotes from admirers, and extended quotes from himself. There are satisfied recollections of witty “sallies” and well-received lectures: “I think my speech went down quite well.” He notes instances of esprit de l’escalier about what he would have, should have, said to finish off obtuse clerics and scientific critics of the idea that selection works on the level of the gene; there are gracious acknowledgments of assistance from his wife, his editors and agents, research assistants and “winsomely charming” TV producers. And there are some less‑than-gracious paybacks to incompetent TV producers, choleric outbursts against creationist stitch-ups that made him seem to come off badly in debates, and outraged accounts of bad behaviour by American fundamentalist preachers.

There are also tips on clever ways of impressing Oxford-entrance examiners, suggestions for more rational procedures for reading and evaluating student admission applications, as well as a not wholly tongue-in-cheek recommendation that A-levels be replaced by University Challenge-style general knowledge quizzes to see “if you have the sort of mind that would benefit from a university education”. Names of people he has met are dropped liberally into the narrative: Neil Armstrong, Bill Gates, John Cleese, Claire Bloom, Freddie Ayer, James Watson, Francis Crick, David Attenborough and even the Queen – who deigned to notice, though not to admire, one of the animal-themed ties that his wife specially designed for him.

At his best, Dawkins has written with passion, urgency and clarity, and, if crushing the creationists and convincing the enemies of reason of their stupidity has secured him a reputation as something of a one-trick pony, it has been a polished trick and a best-in-show pony. But this is not Dawkins at his best. Brief Candle consists of scattered reflections on a life and on a set of public performances. It adds only a little to the science lessons and, compared with the first volume of the memoirs (which was itself a guarded performance), it’s stingy with insights into his personal life.

Dawkins retired as “public understanding” professor in 2008, and he is now in his mid-70s. He basks in the knowledge that he is worshipped by many, but he also seems aware that others – including those who would like to be counted among his intellectual allies – have long believed his cask-strength hectoring would have benefited from a splash of water and a willingness to teach rather than preach. You don’t read Dawkins to be converted from faith to science – though that’s possible; you read him to be fortified in your secular beliefs and to be armed against the Dark Side with handy facts, gestures at powerful theories, and rich stores of satirical rhetoric.

It’s to Dawkins’s credit here that he gives a little space to a fellow science populariser, the American physicist Neil deGrasse Tyson, making an impromptu suggestion that Dawkins might be more effective in selling his scientific wares if he did some market research. “You are professor of the public understanding of science,” Tyson said, “not professor of delivering truth to the public, and these are two different exercises. Persuasion isn’t always ‘Here’s the facts, you are either an idiot or you’re not.’ It’s ‘Here’s the facts, and here is a sensitivity to your state of mind.’ And I worry that your methods, and how articulately barbed you can be, end up simply being ineffective.” Dawkins reports that he “gratefully accepted the rebuke”, but there’s no evidence here that he recognised its wisdom.

• Steven Shapin’s Never Pure is published by Johns Hopkins. To order a copy of Brief Candle in the Dark for £16, go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min. p&p of £1.99.