The Hebrew University of Jerusalem on Wednesday revealed a trove of 110 previously unpublished documents and letters written by Albert Einstein, ahead of the famed Jewish physicist’s 140th birthday which will be marked next week.

The newly unveiled handwritten documents were donated to the university’s archive by the Crown Goodman family, private collectors based in the United States. They include various work documents, a previously unpublished annex to a 1930 academic article on gravitation and electromagnetism, and a 1935 letter to his son, Hans Albert.

The letter was written while Hans Albert was living in Zurich, Switzerland, with his mother Mileva Maric and his mentally ill brother Eduard.

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The letter begins with Albert Einstein apologizing for not answering a previous message because he was “so much in the claws of the mathematical devil that I don’t get around to any personal writing at all, because I am chasing after hopeless goals that my head is good for nothing of a contemplative nature.”

The letter included a passage that Hebrew University researchers believe to be denouncing psychoanalysis founder Sigmund Freud as a fraud. Eduard Einstein — referred to as “Tetel” in his father’s letters — “greatly admired” Freud, the researchers said, and could have been treated by him at the time.

Einstein said in the letter that he wouldn’t be willing to pay for “Tetel’s crazy house of treatment,” adding that “I am almost positive that the thing with the Viennese doctor is a simple swindle, and I am very surprised that no one in Zurich is preventing your mother from falling for it and so to ruin her financial position even further.”

In the same letter, written four years before the start of World War II, Einstein talks about his fear of war in Europe due to “German bandits.”

“I believe that even in Germany things are slowly starting to change,” he wrote. “Let’s just hope we won’t have a Europe war first. The German armament must be extremely dangerous; but the rest of Europe is now starting to finally take the thing seriously, especially the English. If they would have come down hard a year and a half ago, it would have been better and easier.”