Editor’s Note: Dr. Kwasniewski is taking a short break from writing new material for OnePeterFive while he finishes a number of books he has agreed to deliver to publishers. We wish him well in these endeavors and may reprint from time to time some of his earlier and now mostly forgotten articles until his return.
Not many Catholics today know about the Syllabus of Errors—but they should. Mocked (naturally) by the fashionable at the time of its issuance in 1864, Pius IX’s thundering condemnation of modern errors has demonstrated its prescient accuracy as the world around us, embracing these errors to the full, races heedlessly to its own destruction. The history of the compilation and promulgation of the Syllabus of Errors is quite complex but the central motivation behind it is easy to grasp:
All this alarming news [of revolution and rebellion] succeeded in convincing Pius IX that liberalism, the synthesis of the 18th-century Encyclopedists’ philosophy, recast in a political form by the French revolutionaries, was truly “the error of the century,” an error he was duty-bound to condemn once again by drawing the attention of Catholics to all the forms—sometimes subtle ones—that this tendency could assume in the concrete.
After a lengthy gestation, the Syllabus and the encyclical to which it was appended, Quanta Cura, were issued on December 8, 1864, accompanied by a letter from the Secretary of State, Cardinal Antonelli. Intended for bishops who had the training required to read it carefully, the Syllabus quickly fell into the hands of simple-minded journalists who, like their counterparts a hundred years later at the time of the Second Vatican Council, reveled in superficial exaggerations, making the document and its promulgator the subject of front-page controversy.
Quanta Cura and the Syllabus are presented as a summary of teaching already set forth by the pope in allocutions and other documents going back to his inaugural encyclical Qui Pluribus of 1846. Quanta Cura denounced views typical of the Enlightenment, honing in on its definitive idea: the “impious and absurd principle of naturalism,” which teaches that
the best constitution of public society and [also] civil progress altogether require that human society be conducted and governed without regard being had to religion any more than if it did not exist; or, at least, without any distinction being made between the true religion and false ones. (§3)
The banishment of religion from civil society and government cannot but darken and eventually extinguish justice and rights, replacing them with egoism, avarice, and violence (§4). The Pope states that the modern opinions mentioned in the encyclical—and, implicitly, those catalogued in the Syllabus—are to be held “reprobated, proscribed, and condemned by all children of the Catholic Church” (§6).
What, specifically, were these opinions? The Syllabus of the Principal Errors of Our Time, to give the document its full title, consists of eighty propositions, divided into ten categories. The first three (“Pantheism, naturalism, and absolute rationalism”; “Moderate rationalism”; “Indifferentism, latitudinarianism”) are predominantly speculative in content, regarding errors about the existence of God and His providence, the divinity of Christ and the truth of Christian revelation, the relationship of faith and reason, and the necessity of the Church for salvation. The seven remaining categories concern chiefly social errors.
It will suffice here to cite a few representative condemned propositions:
- The Church is not a true and perfect society divinely endowed with proper and perpetual rights, but rather an organization under the power of civil law (n. 19), whose immunity of personnel and property derive from civil law (n. 30).
- In case of conflict, civil law prevails over canon law (n. 42).
- The education of children belongs by right to the State, not to parents or to the Church (n. 45 and others).
- Church and State ought to be separated (n. 55).
- Rights are nothing other than accomplished facts (n. 59).
- “Authority is nothing else but numbers and the sum total of material forces” (n. 60).
- The marriage contract is not indissoluble by the law of nature, and divorce may therefore be permitted (n. 67).
The final category, “Errors having reference to contemporary liberalism [liberalismum hodiernum],” gained special notoriety at the time of promulgation. Here, the Pope condemns four propositions:
- “In the present day it is no longer expedient that the Catholic religion should be held as the only religion of the State, to the exclusion of all other forms of worship” (n. 77).
- It is wise to pass laws allowing non-Catholic immigrants the public exercise of their religion (n. 78).
- It is false that liberty of public worship and freedom of speech conduce more easily to corruption of morals and religious indifferentism (n. 79).
- “The Roman Pontiff can and should reconcile and harmonize himself with progress, liberalism and modern [recenti] civilization” (n. 80).
The internal structure of the Syllabus dictates its correct interpretation. Each of the eighty propositions is followed by a citation of papal document(s) in which this particular error had already been discussed and censured by the pope. Antonelli’s letter instructed the reader to gauge the tenor and scope of condemned propositions from their source documents.
Take, for example, the last proposition (n. 80), where it may seem that the pope is repudiating modern civilization tout court. A glance at the source proves otherwise. In an allocution of March 18, 1861, Pius IX had railed against those who expected him to surrender to “what they call modern civilization and liberalism,” which amounted to shutting down monasteries, secularizing schools, harassing priests, supporting anarchists and communists, etc. He concluded: “If by the word ‘civilization’ must be understood a system invented on purpose to weaken, and perhaps to overthrow, the Church, never can the Holy See and the Roman Pontiff be allied with such a civilization!”—hardly a surprising conclusion. It is to this allocution that n. 80 of the Syllabus directs us.
At the time of promulgation, well-trained clerics were aware of “the classical rule that when we are faced with a proposition censured by the Church’s teaching authority, in order to know the positive teaching of the Church in the matter, we must take the contradictory of the proposition and not its contrary, as one is naturally tempted to do.” In other words, if the Church were to condemn the proposition that democracy is the only legitimate form of government, one may conclude positively only that democracy is not the only legitimate form of government—not that democracy is an illegitimate form of government. Or if she rejects the statement that “Every man is free to embrace and profess that religion which, guided by the light of reason, he shall consider true” (n. 15), positively this means the light of reason is not the only guide as regards religious truth—not that one should not be guided by the light of reason as regards religious truth. (The documentary source of n. 15 is again illuminating: the pope is there condemning the rationalist view that human reason is the sole measure of truth and right, and thus the sole means for learning or handing down what is true and right.) One may derive the contradictory proposition by adding to each condemned proposition the words: “It is not the case that…” This negation leaves untouched a considerable realm of possibilities beyond what is specifically rejected.
It is also important to interpret the censured propositions in light of the concrete historical situation. Pius IX’s predecessor, Gregory XVI, a fierce opponent of liberalism, was prepared to accept compromises in practice—such as the new Belgian constitution of 1831 which endorsed separation of Church and State—while maintaining that, in principle, such arrangements were imperfect and could never be held up as ideal; Pius IX was no different; nor was his successor Leo XIII. We might be tempted to view this kind of pragmatism as a hypocritical double-standard, but that would be unjust. The popes never failed to proclaim the fullness of the truth even when they were willing to collaborate with less-than-perfect governments in order to minister to the Catholic faithful throughout the world. No one can fail to see the difference between this approach and the Second Vatican Council’s eternally confusing Dignitatis Humanae, which led to the abolition of Catholic privileges in most States where they still existed, undermined the coherent witness of the preceding Magisterium, and supplied low-cost energy to the factory of fictitious rights.
Unquestionably Pius IX’s Syllabus of Errors represents official papal teaching, an act of the Magisterium that requires our assent. As a matter of fact, it enjoys a high status due to its propositional structure, its copious cross-referencing, its precise teaching as established by its sources, and the tenor of its language. Its content is perennial: though summoned by immediate and local threats, such content is no more time-conditioned than any statement of dogmatic or moral truth (e.g., nn. 1–14 on God, nn. 56–64 on ethics, nn. 65–74 on marriage).
The Syllabus with its companion encyclical cannot be set aside as if they had lost their relevance, belonging to a now-superseded “Constantinian” or “integrist” phase. The Syllabus continues to serve the purpose for which it was promulgated in 1864: putting the Catholic world on its guard against the profane, materialistic, libertine axioms of the new world order that was inaugurated with the French Revolution and soon became the political program of anticlericals and anarchists, soft or hard, throughout the world. It requires no special acumen to trace lines of direct causality from the archetypal errors collected in the Syllabus to the widespread errors—if anything, more perverse and destructive—targeted more than a century later in the encyclicals of John Paul II and Benedict XVI.
Far from being an antique curiosity, Pius IX’s Syllabus of Errors is a prophetic document of major importance in the early stages of modern Catholic social teaching, and it is fair to say that it will outlive many of the wordier and woolier documents of recent decades.
 See E.E.Y. Hales, Pio Nono. A Study in European Politics and Religion in the Nineteenth Century (London: Eyre & Spottiswoode, 1954), 255–90; J. Derek Holmes, The Triumph of the Holy See. A Short History of the Papacy in the Nineteenth Century (London: Burns & Oates, 1978), 145–51.
 Roger Aubert, “Religious Liberty from Mirari Vos to the Syllabus,” in Historical Problems of Church Renewal, Concilium, vol. 7 (Glen Rock, NJ: Paulist Press, 1965), 97.
 See Aubert, “Religious Liberty,” 101–2; Hales, Pio Nono, 258.
 Aubert, 101.
 See, inter alia, Michael Davies, The Second Vatican Council and Religious Liberty (Long Prairie, Minnesota: The Neumann Press, 1992), 56–62, 267–74; Brian Harrison, Religious Liberty and Contraception (Melbourne: John XXIII Fellowship Co-op, 1988), esp. 31–61.
 One does find some mention of issues and policies which, being bound up with the particularities of a given society, unavoidably involve prudential judgment on the part of authorities. For example, a Catholic regime in a predominantly Catholic society should privilege the Church, but it would make little sense to say that special favor should be shown to the Church by a non-Catholic government in a pluralistic society, a scenario not envisioned in the documentary sources of the Syllabus.
Dr. Peter Kwasniewski is a graduate of Thomas Aquinas College and The Catholic University of America who taught at the International Theological Institute in Austria, the Franciscan University of Steubenville’s Austria Program, and Wyoming Catholic College, which he helped establish in 2006. Today he is a full-time writer and speaker on traditional Catholicism whose work appears online at, among others, OnePeterFive, New Liturgical Movement, LifeSiteNews, The Remnant, and Catholic Family News. He has published eighteen books, including Reclaiming Our Roman Catholic Birthright: The Genius and Timeliness of the Traditional Latin Mass (Angelico, 2020), The Ecstasy of Love in the Thought of Thomas Aquinas (Emmaus, 2021), and Are Canonizations Infallible? Revisiting a Disputed Question (Arouca, 2021). His work has been translated into at least eighteen languages. Visit his website at www.peterkwasniewski.com.