 The promotion of socialist education met with strong opposition in some parts of academia and in areas that had been controlled by the Cristeros.Pope Pius XI also published the encyclical "Firmissimam constantiam" on March 28, 1937, expressing his opposition to the "impious and corruptive school" (paragraph 22) and his support for Catholic Action in Mexico.That was the third and last encyclical published by Pius XI that referred to the religious situation in Mexico.