During World War II, she lived for a time in Marseille, receiving spiritual direction from Joseph-Marie Perrin, a Dominican Friar. Around this time, she met the French Catholic author Gustave Thibon, who later edited some of her work. Weil did not limit her curiosity to Christianity. She was interested in other religious traditions—especially the Greek and Egyptian mysteries; Hinduism (especially the Upanishads and the Bhagavad Gita); and Mahayana Buddhism. She believed that all these and other traditions contained elements of genuine revelation, writing that:  Greece, Egypt, ancient India, the beauty of the world, the pure and authentic reflection of this beauty in art and science...these things have done as much as the visibly Christian ones to deliver me into Christ's hands as his captive. I think I might even say more. She was, nevertheless, opposed to religious syncretism, claiming that it effaced the particularity of the individual traditions:  Each religion is alone true, that is to say, that at the moment we are thinking of it we must bring as much attention to bear on it as if there were nothing else ... A "synthesis" of religion implies a lower quality of attention. In 1942, Weil travelled to the United States of America with her family. She had been reluctant to leave France, but agreed to do so as she wanted to see her parents to safety and knew they would not leave without her. She was also encouraged by the fact that it would be relatively easy for her to reach Britain from the United States, where she could join the French Resistance. She had hopes of being sent back to France as a covert agent. Older biographies suggest Weil made no further progress in achieving her desire to return to France as an agent—she was limited to desk work in London, although this did give her time to write one of her largest and best known works: "The Need for Roots". Yet there is now evidence that Weil was recruited by the Special Operations Executive, with a view to sending her back to France as a clandestine wireless operator. In May 1943, plans were underway to send her to Thame Park in Oxfordshire for training, but were cancelled soon after, as her failing health became known. The punishing work-régime she assumed soon took a heavy toll; in 1943, she was diagnosed with tuberculosis and instructed to rest and eat well. However, she refused special treatment because of her long-standing political idealism and her detachment from material things.