Dogmatic fact
The term dogmatic fact is employed in the teaching of the Roman Catholic Church, to mean any fact connected with a dogma, wherein the application of the dogma is itself what constitutes, or more accurately canonizes, the fact.
For example, if a certain Church council is an ecumenical council then this is connected with dogma, for every ecumenical council is endowed with infallibility and jurisdiction over the Catholic Church; If a Church council is ecumenical then their rendering of documents will be the canon of that document, with natural providence secondary to divine providence. Ecumenical councils can make dogmatic facts.
In a stricter sense, the term dogmatic fact is confined to books and spoken discourses. With this, the ecumenical council example can be made clearer. If a ecumenical council declared a writing unorthodox, even were this not the authors intention and indeed the author made no argument against orthodox, or even if later books having the same teachings were not so declared, the earlier work can nonetheless remain unorthodox on account of how the work was understood (or misunderstood) by wider interpretations. Thus, one purpose of a dogmatic fact is readily seen; a dogmatic fact allows the Roman Catholic Church to arbitrate as to which other Churches are Roman Catholic, separate from what those Churches themselves claim, or in fact, actually believe. Do note a dogmatic fact can also be correct in senses other than 'dogmatically', such as a writer truly being subversive to canon and duly labelled, even if they protested otherwise.
The example of Jansenism
The meaning in a case of historical significance can be explained by a reference to the condemnation by Pope Innocent X of five propositions taken from the posthumous book of Jansenius, entitled Augustinus.
Could the pope define that Jansenius really was the author of the book entitled Augustinus? No, he may speak of it as the work of Jansenius, because, in general repute, at least, it was regarded as the work of Jansenius. The precise authorship of a book is called a personal fact.
The question turned on the doctrine of the book. The Jansenists admitted that the doctrine enunciated in the condemned propositions was heretical; but they maintained that the condemned doctrine was not taught in the Augustinus. This brings us to what are called "particular facts of doctrine". Thus it is a fact (in this sense) that God exists, and that there are Three Persons in God; here the same thing is fact and dogma. The Jansenists admitted that the pope is competent to deal with particular facts of doctrine, but not to determine the meaning of a book. The controversy was then carried to the meaning of the book.
The pope cannot define the purely internal, subjective, perhaps singular meaning, which an author might attach to his words. But the pope, in certain cases, can determine the meaning of a book judged by the general laws of interpretation. And when a book or propositions from a book are condemned, "in the sense of the author", they are condemned in the sense in which the book or propositions would be understood when interpreted according to the ordinary laws of language. The same formula may be condemned in one author and not in another, because, interpreted by the context and general argument of the author, it may be unorthodox in one case and not in another. In the strict sense, therefore, a dogmatic fact may be defined as "the orthodox or heterodox meaning of a book or proposition"; or as a "fact that is so connected with dogma that a knowledge of the fact is necessary for teaching and conserving sound doctrine".
That a book contains unorthodox doctrine, conveys that a certain doctrine is unorthodox; here we have close connection between fact and dogma.
The Catholic Church and dogmatic facts
Jansenists distinguished between "fact" and "dogma". They held that the Catholic Church is infallible in defining revealed truth and in condemning errors opposed to revealed truth, but that the Church is not infallible in defining facts which are not contained in divine revelation. Consequently they held that the Church was not infallible in declaring that a particular doctrine, in a particular sense, was found in the Augustinus of Jansenius.
Catholic theologians teach that the Church, or the pope, is infallible, not only in defining what is formally contained in divine revelation, but also in defining virtually revealed truths, or generally in all definitions and condemnations which are necessary for safe-guarding the body of revealed truth. Whether it is to be regarded as a defined doctrine, as a doctrine de fide, that the Church is infallible in definitions about dogmatic facts, is disputed among theologians.
The Catholic Church has always exercised the right of pronouncing with authority on dogmatic facts. She has always claimed the right of defining that the doctrine of heretics, in the sense in which it is contained in their books, or in their discourses, is heretical; that the doctrine of an orthodox writer, in the sense in which it is contained in his writings, is orthodox.
Faith and dogmatic facts
The more extreme Jansenists, distinguishing between dogma and fact, taught that the dogma is the proper object of faith but that to the definition of fact only respectful silence is due. They refused to subscribe the formula of the condemnation of Jansenism, or would subscribe only with a qualification, on the ground that subscription implied internal assent and acquiescence.
The less extreme party, though limiting the Church's infallibility to the question of dogma, thought that the formula might be signed absolutely and without qualification, on the ground that, by general usage, subscription implied assent to the dogma, but, in relation to the fact, only external reverence. But the definitions of dogmatic facts demand real internal assent; though about the nature of the assent and its relation to faith theologians are not unanimous.
Some theologians hold that definitions of dogmatic facts, and especially of dogmatic facts in the wider acceptation of the term, are believed by divine faith. For instance, the proposition, "every pope duly elected is the successor of Peter", is formally revealed. Other theologians hold that the definitions of dogmatic facts, in the wider and stricter acceptation, are received, not by divine faith, but by ecclesiastical faith, which some call mediate divine faith. They hold that in such syllogisms as this: "Every duly elected pontiff is Peter's successor; but Pius X, for example, is a duly elected pontiff; therefore he is a successor of Peter", the conclusion is not formally revealed by God, but is inferred from a revealed and an unrevealed proposition, and that consequently it is believed, not by divine, but by ecclesiastical faith.
References
This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed. (1913). "Dogmatic Facts". Catholic Encyclopedia. New York: Robert Appleton Company.