At the beginning of his time at Berkeley, Oppenheimer embodied the ivory tower intellectual, and, caring nothing for politics or current events, he isolated himself from both. Immersed in physics and spending all his spare time pondering Hindu mythology or the classics of the ancient world, Oppenheimer had no time to spare for worldly matters.
He had no phone, no radio, and never read the newspaper, and, so, was completely unaware of everything going on beyond the bounds of Berkeley. When the stock market crashed, ushering in the Great Depression, Oppenheimer took no notice of it. After all, he lived off a trust fund from his parents, and thus he was not economically affected. He remained unaware of the country's dire straits until six months later, when someone mentioned the stock market crash to him in casual conversation.
But the events of the 1930s were soon to shock Oppenheimer out of his apathy. As he has said, seeing how the Depression affected his students forced him to understand "how deeply political and economic events could affect men's lives." It was the beginning of a newly aware, politically active Oppenheimer.
The physicist's new political resolve was soon strengthened by events abroad. Fascism had begun to take hold across Europe, as Adolf Hitler swept into power in Germany and as Spain was taken over by General Francisco Franco. Oppenheimer had German roots, and it was clear to him that Hitler was no friend of the German Jews.
His distaste for European fascism and his distress about the precarious state of the American economy may have shocked Oppenheimer into awareness, but it wasn't until he met a passionate, radical woman, Jean Tatlock, that he was propelled into action.
Tatlock was a graduate student at Berkeley, working toward a degree in psychology. She was also a member of the Communist Party. This was not unusual in the 1930s. Communism was a standard path for young liberals to take, and it was an allegiance that they often claimed quite openly at the time. The Communist Party was seen as a liberal, reformist party that worked for integration, fair wages, and other popular causes. Perhaps most appealing to Oppenheimer, the communists stood solidly against fascism, and supported the causes of oppressed peoples abroad.