The “God letter” was written in 1954 in Einstein’s native German in response to the work of the philosopher Eric Gutkind.
In the letter, the theoretical physicist outlines his thoughts on religion and his own Jewish identity.
“This remarkably candid, private letter was written a year before Einstein’s death and remains the most fully articulated expression of his religious and philosophical views,” a statement from Christie’s auction house in New York said.
The letter was sold for almost twice the auction house’s expected value of between $1m and $1.5m.
In his letter, Einstein states: “The word God is for me nothing but the expression and product of human weaknesses, the Bible a collection of venerable but still rather primitive legends.
“No interpretation, no matter how subtle, can [for me] change anything about this.”
He also gives his thoughts on his own Jewish identity, stating the religion is “like all other religions, an incarnation of primitive superstition”.
“And the Jewish people to whom I gladly belong, and in whose mentality I feel profoundly anchored, still for me does not have any different kind of dignity from all other peoples,” he writes.
“As far as my experience goes, they are in fact no better than other human groups, even if they are protected from the worst excesses by a lack of power. Otherwise I cannot perceive anything ‘chosen’ about them.”
Earlier this year, another of Einstein’s letters warning of the rise of antisemitism more than a decade before the Nazis seized power in Germany was auctioned for $32,000.
Two notes briefly outlining the physicist’s thoughts on life and happiness sold at auction for $1.5m last year.
The publication of his personal diaries this year revealed his racist attitudes towards foreigners. In the private writings, he describes the Chinese as an “industrious, filthy, obtuse people” and writes of “bandit-like filthy Levantines”.
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