Well-known atheist Richard Dawkins, author of the book "The Selfish Gene," recently celebrated the 40th anniversary of his work by saying that the book on evolution is still as relevant today as it was when it was first published back in 1976.

BBC News asked him if his other books, such as the 2006 bestseller "The God Delusion," might have been a "step too far." But Dawkins does not think so, although he promises never to write any more anti-religious books.

"I've stepped back," says Dawkins. "I haven't written any more books along those lines. 'The God Delusion' is a one-off. Not one that I'm ashamed of; I'm very proud of it. But it's a one-off."

Dawkins has made several controversial comments regarding faith in the past. He once said that he is offended by the sight of women wearing the burqa, the outer garment worn by some Muslim women to cover their bodies when in public. He even said that Muslim faith schools teach children "alien rubbish."

Even though his comments have upset a large number of people, Dawkins says he stands by them all. "It's important to [be involved in those debates]. I think scientists need to get involved in that kind of thing," he says.

"Religion is not really a field that you can have. It's a non-field," Dawkins adds. "And insofar as religion makes claims in the area of science—which it does, because it talks about creation, it talks about the nature of the Universe, it talks about the nature of life—to that extent, all scientists should be involved in it."

Dawkins has been using social media in airing his views, although he says he has long given up on Twitter. Every so often, his staff at the Foundation for Reason and Science would post some of his comments, but the scientist has given up doing it himself.