In 1968, Pope Paul VI taught that a husband and wife, in full recognition of their own duties toward God, themselves, the family and society, should respect the fact that in the task of the transmission of life, they must conform their activity to the creative intention of God, expressed in the very nature of marriage and of its acts, and manifested by the constant teaching of the Church.1 This teaching precluded every action that renders procreation impossible, either as an end or a means, through the acts of contraception or sterilization. Pope Pius XII taught that if there are...