Albert Einstein described belief in God as "childish superstition" and said Jews were not the chosen people, in a letter to be sold in London this week, an auctioneer said Tuesday.
The father of relativity, whose previously known views on religion have been more ambivalent and fuelled much discussion, made the comments in response to a philosopher in 1954.
As a Jew himself, Einstein said he had a great affinity with Jewish people but said they "have no different quality for me than all other people".
"The word God is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honourable, but still primitive legends which are nevertheless pretty childish.
"No interpretation no matter how subtle can (for me) change this," he wrote in the letter written on January 3, 1954 to the philosopher Eric Gutkind, cited by The Guardian newspaper.
The German-language letter is being sold Thursday by Bloomsbury Auctions in Mayfair after being in a private collection for more than 50 years, said the auction house's managing director Rupert Powell.
In it, the renowned scientist, who declined an invitation to become Israel's second president, rejected the idea that the Jews are God's chosen people.
"For me the Jewish religion like all others is an incarnation of the most childish superstitions," he said.
"And the Jewish people to whom I gladly belong and with whose mentality I have a deep affinity have no different quality for me than all other people."
And he added: "As far as my experience goes, they are no better than other human groups, although they are protected from the worst cancers by a lack of power. Otherwise I cannot see anything 'chosen' about them."
Previously the great scientist's comments on religion -- such as "Science without religion is lame, religion without science is blind" -- have been the subject of much debate, used notably to back up arguments in favour of faith.
Powell said the letter being sold this week gave a clear reflection of Einstein's real thoughts on the subject. "He's fairly unequivocal as to what he's saying. There's no beating about the bush," he told AFP.