Freeman Dyson: J. Robert Oppenheimer::
I often wondered how it happened that Oppenheimer changed his character so suddenly, from the left-wing bohemian intellectual at Berkeley to the good soldier at Los Alamos. I believe that an important clue to this change is the story of Joe Dallet. In his autobiographical statement at the security hearings, Oppenheimer said:
It was in the summer of 1939 in Pasadena that I first met my wife…. I learned of her earlier marriage to Joe Dallet, and of his death fighting in Spain…. When I met her I found in her a deep loyalty to her former husband…
After Oppenheimer married Kitty in 1940, they continued to live with the ghost of Joe Dallet. Later I learned from the historian Richard Polenberg some facts about Joe Dallet’s life and death.
Dallet was unlike the majority of the left-wing intellectuals who flocked to Spain to fight for the republic. Dallet took soldiering seriously. He believed in discipline. He quickly became an expert on the repair, maintenance, and use of machine guns. He drilled his troops with old-fashioned thoroughness, making sure that they knew how to take care of their weapons and how to use them effectively. In an anarchic situation, his unit was conspicuously well organized. His men caught from him the habit of competence, the pride of a steelworker who knew how to handle machinery. At moments of relaxation, he talked mostly about his beloved machine guns. This was the image of Joe that Joe’s friends brought to Kitty in Paris when they came to see her after his death. This was the image that Kitty brought to Oppenheimer when she married him.
From Spain to Los Alamos was a short step. Oppenheimer was as proud of his bombs as Joe Dallet had been proud of his guns. Oppenheimer became the good soldier that Kitty loved and admired. Through the Los Alamos years and for twenty years afterward, the spirit of Joe Dallet lived on in Robert Oppenheimer.