"Una Caro (One Flesh): In Praise of Monogamy" is the title of a 40-page publication that the Vatican's Dicastery for the Doctrine of Faith issued. It outlines the Catholic Church's tenet that marriage is a singular and exclusive union between a man and a woman. Although the text mentions that the Church has focused more on the indissolubility of marriage than on the unity of the partners, it nevertheless emphasizes that marriage demands both. Unity is defined as the mutual belonging of two individuals that is unshareable with anybody else.
Through Scripture, Church teachings, and cultural allusions, such as Indian traditions and the poetry of Pablo Neruda and Walt Whitman, the paper examines the notion of unity in marriage. In order to promote monogamous relationships, Cardinal Víctor Manuel Fernández said that the document was written in response to demands from African bishops serving in communities where polygamy is prevalent.