Summi Pontificatus is an encyclical of Pope Pius XII published on October 20, 1939. The encyclical is subtitled "On the Unity of Human Society." It was the first major encyclical of Pius XII so was seen as setting "a tone" for his papacy. It critiques major errors at the time, such as ideologies of racism and cultural superiority and the totalitarian state. It also sets the theological framework for future encyclical letters, such as Mystici Corporis Christi (1943). The encylical laments the destruction of Poland, rejects the Molotov-Ribbentrop Pact and calls for a restoration of independent Poland.
The Unity of Human Society
Summi Pontificatus sees Christianity being universalized and opposed to racial hostility and superiority. There are no racial differences, because the human race forms a unity, because "one ancestor [Adam] made all nations to inhabit the whole earth".
- What a wonderful vision, which makes us contemplate the human race in the unity of its origin in God. . . in the unity of its nature, composed equally in all men of a material body and a spiritual soul; in the unity of its immediate end and its mission in the world; in the unity of its dwelling, the earth, whose benefits all men, by right of nature, may use to sustain and develop life; in the unity of its supernatural end: God himself, to whom all ought to tend; in the unity of the means for attaining this end;. . . in the unity of the redemption wrought by Christ for all.
Human and cultural diversity
Summi Pontificatus teaches, that superior and inferior cultures do not exist and that different levels of development within and between nations are source for enrichment of the human race.
- The nations, despite a difference of development due to diverse conditions of life and of culture, are not destined to break the unity of the human race, but rather to enrich and embellish it by the sharing of their own peculiar gifts and by that reciprocal interchange of goods.
Solidarity and charity
Because of the common origin and the ensuing equality, solidarity and charity are mandatory for all people. The principle of solidarity, which can be articulated in terms of "friendship" or "social charity," is a direct demand of human and Christian brotherhood.
- An error, "today abundantly widespread, is disregard for the law of human solidarity and charity, dictated and imposed both by our common origin and by the equality in rational nature of all men, whatever nation they belong to. This law is sealed by the sacrifice of redemption offered by Jesus Christ on the altar of the Cross to his heavenly Father, on behalf of sinful humanity.
Forgetfulness of the law of universal charity—may lead to conflict and war. Because that charity alone can create and consolidate peace by extinguishing hatred and softening envies and dissensions in the relations between nations.
The totalitarian state
Summi Pontificatus gained attention for its rejection of the state becoming "something ultimate to which everything else should be subordinated", which most saw as a rejection of totalitarianism. Summi Pontificatus links men as brothers by the common recognition of a supernatural ownership.
- But there is yet another error no less pernicious to the well-being of the nations and to the prosperity of that great human society which gathers together and embraces within its confines all races. It is the error contained in those ideas which do not hesitate to divorce civil authority from every kind of dependence upon the Supreme Being--First Source and absolute Master of man and of society--and from every restraint of a Higher Law derived from God as from its First Source. Thus they accord the civil authority an unrestricted field of action that is at the mercy of the changeful tide of human will, or of the dictates of casual historical claims, and of the interests of a few.
A threat to its families, education
Summi Pontificatus goes on to show that unlimited state authority is a menace to the prosperity of nations, to the family and to education.
Further, there would be danger to the primary and essential cell of society, the family, which in a totalitarian system would be viewed from the narrow standpoint of national power. That is contrary to Church teaching, that family has priority before the state:
- However, and lest it be forgotten that man and the family are by nature anterior to the State, and that the Creator has given to both of them powers and rights and has assigned them a mission and a charge that correspond to undeniable natural requirements.
Summi Pontificatus holds also that education would not aim at the balanced and harmonious development of the physical powers and of all the intellectual and moral qualities, but at a one-sided formation of those civic virtues that are considered necessary for attaining political success, while the virtues which give society the fragrance of nobility, humanity and reverence would be inculcated less, for fear they should detract from the pride of the citizen. 
A danger to World peace
The principles of natural and international law are not an option but indispensable, because the totalitarian state is a threat to peace:
- The idea which credits the State with unlimited authority is not simply an error harmful to the internal life of nations, to their prosperity, and to the larger and well-ordered increase in their well-being, but likewise it injures the relations between peoples, for it breaks the unity of supra-national society, robs the law of nations of its foundation and vigor, leads to violation of others' rights and impedes agreement and peaceful intercourse. 
The German/Russian attack on Poland
Summi Pontificatus in line with the theological and non-political nature of Papal encyclicals of the past, does not mention explicitly definite names or countries, as many of his accusations against racism, racial segregationn superiority and exploitation are far-reaching and of a moral nature. An exception is the fate of occupied Poland. For specifically criticizing the attack and occupation of Poland, was of particular interest at the time, and the western Allies applauded the encyclical. Polish refugees outside Nazi and Soviet control likewise applauded that the pope had even called for the restitution of an independent Polish state in future.
- "The blood of countless human beings, even noncombatants, raises a piteous dirge over a nation such as Our dear Poland, which, for its fidelity to the Church, for its services in the defense of Christian civilization, written in indelible characters in the annals of history, has a right to the generous and brotherly sympathy of the whole world, while it awaits, relying on the powerful intercession of Mary, Help of Christians, the hour of a resurrection in harmony with the principles of justice and true peace."
Summi Pontificatus incorporates elements of the never published encyclical "Humani Generis Unitas" against racism and anti-semitism, prepared by several Jesuits for their Father General. Pope Pius XI choose not to publish it in 1938, possibly in light of strong anti-Judaic or anti-rabbinic language in parts of it, which could be misunderstood by the faithful or perverted by pro-Axis media. Some 50 years later, this created some controversy, as to whether the new Pope should have published the encyclical letter of his predecessor without changes or additions. 
The reactions to Summi Pontificatus were strong at the time. While some Nazis played it down, the German ambassador to the Vatican, Von Bergen called it a direct attack on the Third Reich. Pope Pius wanted to hit with this encyclical primarily the Third Reich. The Catholic League (U.S.) states that the Gestapo considered the encyclical an attack. The British and French authorities at war with Germany welcomed it and the French had copies printed and dropped by air over Germany. The New York Times front-page caption on 28 October 1939 stated, "Pope Condemns Dictators, Treaty Violators, Racism; Urges Restoring of Poland".
The American media, without grasping potential implications for domestic race relations, welcomed the decisive positions of the new Pope. More important, devout Catholic that he (Pope Pius XII) is, he knew which side he was for, and, unlike his predecessors during War I, said so.
- It certainly did the Allies no harm when 61,000,000 German and Polish Catholics were told by their Supreme Ruler that "the idea which credits the State with unlimited authority" was abhorrent to him. "To consider the State as something ultimate to which everything else should be subordinated and directed cannot fail to harm the true and lasting prosperity of nations," read the Encyclical. Again, the Pontiff wrote that the totalitarian system of government was an idea which "robs the law of nations of its foundation and vigor, leads to violation of others' rights and impedes agreement and peaceful intercourse.
The encyclical letter certainly did not stop or shorten World War Two. It seemed to have little or no political impact at the time. But Summi Pontificatus also predicted an ultimate victory against the enemies of the Church. "Her adversary can never prevail: The gates of hell shall not prevail, nor can they ever weaken her"  In this, Summi Pontificatus turned out to be correct. Theologically, the often quoted rationale about the unity of human society and diversity of cultures, is a part of the Magisterium of the Catholic Church and quoted in numerous Church documents. Summi Pontificatus, despite of its lack of "political success" remains thus one of the more influential theological encyclicals of Pope Pius XII.
- ↑ Summi Pontificatus, October 20, 1939; AAS 31 (1939) 423 ff.
- ↑ Pius XII, Enc. Summi Pontificatus 3;
- ↑ Pius XII, Enc. Summi Pontificatus 3;
- ↑ Pius XII, Enc. Summi Pontificatus 43
- ↑ Pius XII, Enc. Summi Pontificatus 35;
- ↑ Pius XII, Enc. Summi Pontificatus 51;
- ↑ Pius XII, Enc. Summi Pontificatus 52
- ↑ Pius XII, Enc. Summi Pontificatus, 61
- ↑ Pius XII, Enc. Summi Pontificatus, 62
- ↑ Pius XII, Enc. Summi Pontificatus, 70
- ↑ Pius XII, Enc. Summi Pontificatus 106;
- ↑ Georges Passselecp, Berard Suchecky, L’Encyclique Cachee De Pii XI, Paris, 1995
- ↑ Church practice and Canon Law, did not require publication. The last encyclical of Pius XII was not issued after his death in 1958 by his successor Pope John XXIII. Likewise Pope Benedict XVI incorpotated parts of an unpublished last encyclical from Pope John Paul II in his first letter, Deus Caritas Est
- ↑ Johanna Schmid, Papst Pius Begegnen. Augsburg, 2001, P.80
- ↑ Pius. No dove, Time Maganzine, November 6, 1939
- ↑ Pius XII, Enc. Summi Pontificatus 104,105