This is a commentary on Pope Pius XI"s Encyclical Casti Conubii. During the past centuries of Christianity the attacks of the enemies of the Church have largely been leveled against the truths of faith. In other words, articles of the creed were denied. Today, as not a few Catholic writers are observing, their attacks are increasingly centered on moral truths. That is, the commandments of the decalogue are questioned and rejected. As the heresies of the past led to a high development of the Church's dogmatic teaching so those of the present will unquestionably lead to a more intensive development of ethical truth. As in the past, heresy in the field of faith led the Church authentically to define dogmas of faith, so today, heresy in the field of morals will undoubtedly lead her more definitely to state her position with regard to ethics or moral doctrine. The encyclical on Christian Marriage is an important pronouncement in the field of morals. And it is a pronouncement that was entirely to be expected, since attacks on the moral code are today centering so largely on the family. An example in its pages of an almost dramatic expression of a moral doctrine is found in the words in which the Supreme Pontiff sets forth the Church's view regarding the artificial limitation of the family. "Since therefore," the encyclical reads, "openly departing from the uninterrupted Christian tradition some recently have judged it possible solemnly to declare another doctrine regarding this question, the Catholic Church, to whom God has entrusted the defense of the integrity and purity of morals, standing erect in the midst of the moral ruin which surrounds her, in order that she may preserve the chastity of the nuptial union from being defiled by this foul stain, raises her voice in token of her divine ambassadorship and through Our mouth proclaims anew: any use whatsoever of matrimony exercised in such a way that the act is deliberately frustrated in its natural power to generate life is an offense against the law of God and of nature, and those who indulge in such are branded with the guilt of a grave sin." In his encyclical Pius XI urges a correct knowledge of matrimony and a Catholic Action that will work toward a universal and permanent restoration of true Christian marriage. It was in the hope of contributing something toward the furtherance of these aims that the present brochure was prepared. Granted that the ideal would be for all to read and study the encyclical itself, the fact is that many complain that the text makes difficult reading, and have asked that its content be stated in a somewhat simplified form. This brochure is an attempt to supply such a simplified version. While practically the entire English text is quoted, it is nevertheless broken down into many parts. Furthermore it is interspersed with short analyses, brief comments, and occasional additional explanations and facts. The encyclical on Christian Marriage was given to the world on the last day of the year 1930 and is known under the Latin title Casti Connubii (Of Chaste Wedlock). An encyclical on the same subject, promulgated by Pope Leo XIII on February 10, 1880, carries the Latin title, Arcanum Divinae Sapientiae. Casti Connubii falls logically into three major parts. The first sets forth in a positive way the Catholic position regarding marriage, the second deals with the errors and vices contrary to true marriage and the third with remedies or ways and means of restoring wedlock to its pristine dignity and purity. There is a short preface or exordium.