(CNN)Letters written by Albert Einstein were auctioned on Thursday, giving a look into how one of the most recognizable scientific minds saw the Holocaust unfold around him.
Einstein's letter denouncing 'Hitler-insanity' sells at auction for $134,000
Among several Einstein letters up for sale were three he wrote from 1921 to 1939 that show how he saw the rise of Hitler to power in Germany as well as the Jewish resistance.
In one letter, the German-born Jewish physicist wrote to his sister Maja Winteler-Einstein in 1921, foreshadowing the Holocaust to come by writing that he declined a trip to Munich for the sake of his life and highlighting the wave of anti-Semitism sweeping Munich, according to a spokesman for the auction house Nate D. Sanders.
In another letter dated 1934, Einstein writes to his first wife to send money to care for his son with schizophrenia, according to a spokesman for Nate D. Sanders. He tells her that he has been restricting himself "in the most extreme way" to get by.
"All this is the result of the Hitler-insanity, which has completely ruined the lives of all those around me ..." Einstein wrote, according to the auction house.
"The power of resistance which has enabled the Jewish people to survive for thousands of years has been based to a large extent on traditions of mutual helpfulness," Einstein said in a 1939 letter to Dr. Maurice Lenz, during the persecution of the Jews and just under three months before the outbreak of World War II. "We have no other means of self-defense than our solidarity and our knowledge that the cause for which we are suffering is a momentous and sacred cause."
Bidding on that letter began at $12,000 on Thursday. After receiving 23 bids, the letter sold for $134,344.
An estimated six million Jews died at the hands of the Nazis and their allies in the Holocaust.
Einstein worked to save European Jews, according to Nate D. Sanders. But he renounced his German citizenship in 1933, when Adolf Hitler became the country's leader, and moved to the United States.