The theology of the Christ Mystical Body has occupied a principal place in St. Alberto Hurtado's thought. He developed an anthropology from the Mystical Body in the different moments of his life: the man is called to be a children of God, that is enough to be a man to be able to belong at de Mystical Body, that Christ is present in the poors, and the unity of all men in Christ. This investigation shows the influence of Columba Marmion in our author. The theological anthropology is the foundation of his social morality: the dignity of human person is based in the incarnation of the Word. The option for the poors and social solidarity are part of the social ethics that padre Hurtado has based with his theology of the Christ Mystical Body.