Gandhi's life and teachings inspired many who specifically referred to Gandhi as their mentor or who dedicated their lives to spreading Gandhi's ideas. In Europe, Romain Rolland was the first to discuss Gandhi in his 1924 book Mahatma Gandhi, and Brazilian anarchist and feminist Maria Lacerda de Moura wrote about Gandhi in her work on pacifism. In 1931, notable European physicist Albert Einstein exchanged written letters with Gandhi, and called him "a role model for the generations to come" in a letter writing about him.[106] Einstein said of Gandhi: