He's a busy, well-educated man of 60, so why does he bother? He thinks for a moment. "Because newspaper editors won't accept my articles." Why not? Mr Walter, ever honest, pauses for another moment. "Because they think I'm boring."
Mr Walter, you see, is a noted humanist, manager of the Rationalist Press Association these past 20 years. Not exactly a sexy subject. Doesn't sell many papers. Which is why a big yawn goes round most newspaper offices when yet another letter arrives, picking people up on piddling points. Charles Moore, on retiring as editor of the Spectator, included Mr Walter in the select group of bores he certainly wouldn't miss.
Mr Walter specialises in either correcting people or showing off his erudite knowledge. It was he who pointed out, during the Major Hewitt/ Princess of Wales thing, that Hewitt could be hanged for treason under a 14th-century law that forbids anyone interfering with the wife of the heir to the sovereign. He recently had a letter in this newspaper correcting an article which stated that Virago books had only published female authors. Even though the writer of this article happened to be his own daughter,Natasha Walter. Oh, Mr Walter does not spare people, or himself.
He lives with his second wife, Christine, in a little flat on top of his office in Islington High Street. The National Peace Council is down below. Index on Censorship and Article 19 have their offices just across the road. Greenpeace and CND used to be round the corner. So much for champagne socialism: beards and sandals, the old stereotype, are alive and well in London N1.
The Rationalist Press, a publisher and book club, founded 1899, owns its own building, and the one next door, and has assets worth around £1m. It has 1,500 members worldwide, including Ludovic Kennedy and George Melly. Members often leave it legacies or,when ordering its books or pamphlets, will send £10 instead of £3.
Mr Walter is a third-generation atheist, very proud that his grandparents, on both sides, shrugged off various forms of Protestantism. His father was W Grey Walter, the eminent neurologist, who often appeared on The Brains Trust. "He was a left-wing humanist and believed that science could solve everything."
Nicolas, spelt without an `h', so must get it right or there'll be a letter in the post, was sent to a semi-progressive boarding school called Rendcomb and then read history at Oxford. He wanted to write, and for around 20 years did a variety of hack work in publishing, politics, teaching and journalism, ending up as chief sub-editor on the TLS. He applied to be literary editor of various magazines, as Eng Lit has always been a major interest, but no one would take him - because of his political activities, so he says. "I decided to leave the TLS when they started having signed reviews. That made me very unhappy. I happened to see the advert for the Rationalist Press job and applied. I suppose I am slightly odd, which helped. Most humanists are slightly odd."
How are you odd, Nicolas? "Well I was 40 at the time, with a wife and two young daughters to support. It wasn't exactly a career move. There are no prospects. Saying you help to run a humanist society doesn't qualify you for many other jobs." After 20 years running the press, with a total staff of two and a half, he is still on a salary of £16,000, though he does get cheap accommodation.
He began his left-wing activitiesyoung, speaking and agitating on behalf of various peace campaigns and anarchist movements. He was always demonstrating and being arrested.
In 1967, he spent two months in Brixton prison following a spot of disruption in Brighton at the Labour Party Conference. "Harold Wilson was coming out pro-Vietnam, so we decided to barrack him during a church service. I actually started interrupting tooearly, while George Brown [then deputy prime minister] was speaking. It all ended in pandemonium and eight of us were arrested. They couldn't get us for violent behaviour, as we didn't hit anyone, or even riotous behaviour, as we tried to argue logically, so they got us for indecent behaviour. In Brixton, the other prisoners wanted to know what we'd done in church that was indecent. Prison wasn't too bad. It was worse for our families."
He was last arrested 11 years ago, at an anarchist demonstration at the Cenotaph on Remembrance Sunday, but doesn't expect to join a similar demonstration again. You haven't softened with age? "No, just got more frightened. I can't move quickly enough toavoid violence."
He would go to prison, though, if required, on the blasphemy laws, but doesn't expect it will happen as the authorities seem to have lost interest. In 1977, after the editor of Gay News was arrested for printing an allegedly blasphemous poem, he started sending out copies of the poem. "Supporters of Mrs Whitehouse were very keen to see me prosecuted. They couldn't actually ring me up and ask for a copy, as this might be deemed soliciting, so they asked if it was true I was publishing it. I said, `Send astamped addressed envelope and find out'. I sent them the poem, in their envelope, with no address, so there was no proof I had sent it. The police arrived twice, and I replied `no comment' to all their questions, and they just went away."
He agrees that things are far worse abroad. "Banning some harmless poem for being blasphemous is trivial compared with the death threat to Salman Rushdie - and there are hundreds of other people being persecuted by religious bodies around the world. Thenthere are religious bodies fighting abortion, insisting girls wear headscarves or young boys be circumcised."
So why carry on? Well, there are two things he would like to see repealed, apart from the blasphemy laws. He wants religious education in schools made optional and the end of the constitutional relationship between the Church of England and the monarchy."I object to the interference of religion in our lives and the way the media allows the Church to monopolise moral issues." He'd also like to see Thought for the Day on Radio 4 give humanists a chance - which now looks likely. "We've been pressing the BBC for this since the Twenties. Now it looks as if John Birt is considering it."
One recent success has been the arrival of Sunday trading. "To be honest, I think that was due to society changing rather than our campaigning, though we like to think we helped. It's like the fly on the axletree of the carriage saying, `Look at all the dust I'm making'. Now who wrote that?" He leans forward to find a reference, confirming that it was Francis Bacon. His whole living room is filled with books.
He has no objection, in principle,to any religious belief. All he wants people to do is think, or even think before they think. "Roman Catholics use contraception all the time these days, ignoring their church, but they never think it out and realise something must be wrong with a church which has such a rule. The Pope is highly intelligent but horribly wrong. People know that Jesus could not be born the son of a virgin, but they go on accepting it. If only they would use reason and think things out forthemselves."
But why destroy people's beliefs if it makes them happy?
"It is true that when belief goes many people are at a loss, slip into a vacuum, drift and become very depressed. At the moment God is in decline, so there are a lot of depressed people. What they should do is use reason to work things out, which is whatGod advised. `Let us reason together,' says Isaiah." He reached for his Bible and found the line. "Yes, Isaiah 1:18. I thought it was."
The decline of God doesn't appear to have made him very happy. He continually moans about the state of the modern world. "Things are getting worse. More poverty, more hatred, more division. In the Sixties I did think things could be changed. Now I suspect people are happier in the so-called Third World, living in isolated communities. In Britain, we were probably happier in the Middle Ages. We couldn't cure as many illnesses but we were not oppressed by television and deprived of real experiences. Peopl e now survive on soap operas or the Royal Family, which is the same thing. I think there should be a Campaign for Real Life. I'm cheerful in myself but, yes, I am pessimistic about modern life."
The thought of a Labour government does not give him much hope either. "If someone like Robin Cook was the leader, and the party was committed to Clause IV, I might vote for them. I admit Tony Blair is very clever and he'll probably get in, but his wordsand his writings are empty. He doesn't want to change anything. He looks nice and talks nice but I'm too old to be tempted by that sort of stuff."
So what's the point of it all, Nicolas? "To enjoy life and get along with other people. Then you die, and that's it." Not much to grab hold of there. He then quotes a definition of humanism: "Happiness is the only good; the time to be happy is now; the place to be happy is here; the way to be happy is to make others so."
"Humanists don't have a gospel or a code of rules, that's why there are so few of us. I suppose I believe in `Do as you would be done by'. I try to treat people as ends in themselves, as Kant said. I believe we should always act so that what we do becomes part of a universal law." Hmm, what does that mean? "Well don't drop litter, if you don't want to see litter lying around, though I must admit since I became disabled I have dropped litter and not been able to pick it up."
Twenty years ago he got testicular cancer. One testicle was removed, he received radiotherapy, and all seemed well. Then his digestive system started playing up. He vomited all the time, his weight dropped from 12 to eight stone and he was hovering near death. It took some time before it became clear that the radiotherapy had caused the damage. "I'm sure it happens all the time, but you never hear about it." Part of his intestines were taken away, and he slowly got better, but a few years ago his spine appeared to have been damaged. It has now affected his legs and left him crippled. Presumably you can sue?
"Why should I? It was just bloody bad luck. l'm not complaining. I have only got praise for the people working in hospitals and the social services, even though they are all exhausted and the hospitals are filthy. If I sued the NHS for negligence and won, it would mean there was less money for other people." A fine Christian, sorry, humanist sentiment.
He met his second wife - a Jewish non-believer like his first - in 1957, and they went their different ways, marrying and having children. Their first marriages eventually came to an end and they got married in 1987. "Thirty years exactly to the day we first met. No, it wasn't a paranormal thing. I looked it up in my diary. It happened to be a Saturday."
They are both looking forward to Christmas. Despite being humanists? "Why not? We always have a Christmas tree, decorations and a family gathering. I love the pagan side of Christmas, as well as the hymns and carols. I was a choirboy for 10 years when I was at school.
"One of my favourite television programmes is Songs of Praise. I hate the interviews but love the singing. Oh, I do hope Thora Hird will be doing a compilation programme this year, putting all the best bits of singing together. I like church music, requiems, the sound of the liturgy, the English of the Bible. What I can't stand is the Nativity story, as it's meaningless, but I do like the tunes."