In 1907 Pope Pius X published his encyclical Pascendi Dominici Gregis condemning modernism. The encyclical begins:

The office divinely committed to Us of feeding the Lord’s flock has especially this duty assigned to it by Christ, namely, to guard with the greatest vigilance the deposit of the faith delivered to the saints, rejecting the profane novelties of words and oppositions of knowledge falsely so called. There has never been a time when this watchfulness of the supreme pastor was not necessary to the Catholic body; for, owing to the efforts of the enemy of the human race, there have never been lacking “men speaking perverse things” (Acts xx. 30), “vain talkers and seducers” (Tit. i. 10), “erring and driving into error” (2 Tim. iii. 13). Still it must be confessed that the number of the enemies of the cross of Christ has in these last days increased exceedingly, who are striving, by arts, entirely new and full of subtlety, to destroy the vital energy of the Church, and, if they can, to overthrow utterly Christ’s kingdom itself. Wherefore We may no longer be silent, lest We should seem to fail in Our most sacred duty, and lest the kindness that, in the hope of wiser counsels, We have hitherto shown them, should be attributed to forgetfulness of Our office.

2. That We make no delay in this matter is rendered necessary especially by the fact that the partisans of error are to be sought not only among the Church’s open enemies; they lie hid, a thing to be deeply deplored and feared, in her very bosom and heart, and are the more mischievous, the less conspicuously they appear. We allude, Venerable Brethren, to many who belong to the Catholic laity, nay, and this is far more lamentable, to the ranks of the priesthood itself, who, feigning a love for the Church, lacking the firm protection of philosophy and theology, nay more, thoroughly imbued with the poisonous doctrines taught by the enemies of the Church, and lost to all sense of modesty, vaunt themselves as reformers of the Church; and, forming more boldly into line of attack, assail all that is most sacred in the work of Christ, not sparing even the person of the Divine Redeemer, whom, with sacrilegious daring, they reduce to a simple, mere man.

3. Though they express astonishment themselves, no one can justly be surprised that We number such men among the enemies of the Church, if, leaving out of consideration the internal disposition of soul, of which God alone is the judge, he is acquainted with their tenets, their manner of speech, their conduct. Nor indeed will he err in accounting them the most pernicious of all the adversaries of the Church. For as We have said, they put their designs for her ruin into operation not from without but from within; hence, the danger is present almost in the very veins and heart of the Church, whose injury is the more certain, the more intimate is their knowledge of her. Moreover they lay the axe not to the branches and shoots, but to the very root, that is, to the faith and its deepest fires. And having struck at this root of immortality, they proceed to disseminate poison through the whole tree, so that there is no part of Catholic truth from which they hold their hand, none that they do not strive to corrupt. Further, none is more skilful, none more astute than they, in the employment of a thousand noxious arts; for they double the parts of rationalist and Catholic, and this so craftily that they easily lead the unwary into error; and since audacity is their chief characteristic, there is no conclusion of any kind from which they shrink or which they do not thrust forward with pertinacity and assurance. To this must be added the fact, which indeed is well calculated to deceive souls, that they lead a life of the greatest activity, of assiduous and ardent application to every branch of learning, and that they possess, as a rule, a reputation for the strictest morality. Finally, and this almost destroys all hope of cure, their very doctrines have given such a bent to their minds, that they disdain all authority and brook no restraint; and relying upon a false conscience, they attempt to ascribe to a love of truth that which is in reality the result of pride and obstinacy.

Once indeed We had hopes of recalling them to a better sense, and to this end we first of all showed them kindness as Our children, then we treated them with severity, and at last We have had recourse, though with great reluctance, to public reproof. But you know, Venerable Brethren, how fruitless has been Our action. They bowed their head for a moment, but it was soon uplifted more arrogantly than ever. If it were a matter which concerned them alone, We might perhaps have overlooked it: but the security of the Catholic name is at stake. Wherefore, as to maintain it longer would be a crime, We must now break silence, in order to expose before the whole Church in their true colours those men who have assumed this bad disguise.

4. But since the Modernists (as they are commonly and rightly called) employ a very clever artifice, namely, to present their doctrines without order and systematic arrangement into one whole, scattered and disjointed one from another, so as to appear to be in doubt and uncertainty, while they are in reality firm and steadfast, it will be of advantage, Venerable Brethren, to bring their teachings together here into one group, and to point out the connexion between them, and thus to pass to an examination of the sources of the errors, and to prescribe remedies for averting the evil.

In the last paragraph here, Pius X accuses the modernists of a “clever artifice”, namely presenting their doctrines without order and systematic arrangement, “so as to appear to be in doubt and uncertainty, while they are in reality firm and steadfast.” In other words, according to him, they have a clear and developed system for themselves, which they do not present to other people. He lays out this system himself in the encyclical.

Such a clever artifice is not impossible in principle. Although I will not defend this at the moment, it seems to me that Hans Urs von Balthasar has just such a system, complete and developed in his own mind, but presented to others without order and systematic arrangement. And it may be that the system described in Pascendi could be fairly attributed to some Catholics at the time, at least in many or most respects. But the problem is that since those who hold the system admittedly do not clearly claim to hold it, there is no easy way to distinguish such people from Catholics who are actually in doubt and uncertainty, and who do not hold such a system.

The result of this is that the remedies proposed by Pius X are detailed, but very widespread in scope:

48. All these prescriptions and those of Our Predecessor are to be borne in mind whenever there is question of choosing directors and professors for seminaries and Catholic Universities. Anybody who in any way is found to be imbued with Modernism is to be excluded without compunction from these offices, and those who already occupy them are to be withdrawn. The same policy is to be adopted towards those who favour Modernism either by extolling the Modernists or excusing their culpable conduct, by criticising scholasticism, the Holy Father, or by refusing obedience to ecclesiastical authority in any of its depositaries; and towards those who show a love of novelty in history, archaeology, biblical exegesis, and finally towards those who neglect the sacred sciences or appear to prefer to them the profane. In all this question of studies, Venerable Brethren, you cannot be too watchful or too constant, but most of all in the choice of professors, for as a rule the students are modelled after the pattern of their masters. Strong in the consciousness of your duty, act always prudently but vigorously.

49. Equal diligence and severity are to be used in examining and selecting candidates for Holy Orders. Far, far from the clergy be the love of novelty! God hates the proud and the obstinate. For the future the doctorate of theology and canon law must never be conferred on anybody who has not made the regular course of scholastic philosophy; if conferred it shall be held as null and void. The rules laid down in 1896 by the Sacred Congregation of Bishops and Regulars for the clerics, both secular and regular, of Italy concerning the frequenting of the Universities, We now decree to be extended to all nations. Clerics and priests inscribed in a Catholic Institute or University must not in the future follow in civil Universities those courses for which there are chairs in the Catholic Institutes to which they belong. If this has been permitted anywhere in the past, We ordain that it be not allowed for the future. Let the Bishops who form the Governing Board of such Catholic Institutes or Universities watch with all care that these Our commands be constantly observed.

50. It is also the duty of the bishops to prevent writings infected with Modernism or favourable to it from being read when they have been published, and to hinder their publication when they have not. No book or paper or periodical of this kind must ever be permitted to seminarists or university students. The injury to them would be equal to that caused by immoral reading – nay, it would be greater for such writings poison Christian life at its very fount. The same decision is to be taken concerning the writings of some Catholics, who, though not badly disposed themselves but ill-instructed in theological studies and imbued with modern philosophy, strive to make this harmonize with the faith, and, as they say, to turn it to the account of the faith. The name and reputation of these authors cause them to be read without suspicion, and they are, therefore, all the more dangerous in preparing the way for Modernism.

51. To give you some more general directions, Venerable Brethren, in a matter of such moment, We bid you do everything in your power to drive out of your dioceses, even by solemn interdict, any pernicious books that may be in circulation there. The Holy See neglects no means to put down writings of this kind, but the number of them has now grown to such an extent that it is impossible to censure them all. Hence it happens that the medicine sometimes arrives too late, for the disease has taken root during the delay. We will, therefore, that the Bishops, putting aside all fear and the prudence of the flesh, despising the outcries of the wicked, gently by all means but constantly, do each his own share of this work, remembering the injunctions of Leo XIII. in the Apostolic Constitution Officiorum: Let the Ordinaries, acting in this also as Delegates of the Apostolic See, exert themselves to prescribe and to put out of reach of the faithful injurious books or other writings printed or circulated in their dioceses. In this passage the Bishops, it is true, receive a right, but they have also a duty imposed on them. Let no Bishop think that he fulfils this duty by denouncing to us one or two books, while a great many others of the same kind are being published and circulated. Nor are you to be deterred by the fact that a book has obtained the Imprimatur elsewhere, both because this may be merely simulated, and because it may have been granted through carelessness or easiness or excessive confidence in the author as may sometimes happen in religious Orders. Besides, just as the same food does not agree equally with everybody, it may happen that a book harmless in one may, on account of the different circumstances, be hurtful in another. Should a Bishop, therefore, after having taken the advice of prudent persons, deem it right to condemn any of such books in his diocese, We not only give him ample faculty to do so but We impose it upon him as a duty to do so. Of course, it is Our wish that in such action proper regard be used, and sometimes it will suffice to restrict the prohibition to the clergy; but even in such cases it will be obligatory on Catholic booksellers not to put on sale books condemned by the Bishop. And while We are on this subject of booksellers, We wish the Bishops to see to it that they do not, through desire for gain, put on sale unsound books. It is certain that in the catalogues of some of them the books of the Modernists are not unfrequently announced with no small praise. If they refuse obedience let the Bishops have no hesitation in depriving them of the title of Catholic booksellers; so too, and with more reason, if they have the title of Episcopal booksellers, and if they have that of Pontifical, let them be denounced to the Apostolic See. Finally, We remind all of the XXVI. article of the abovementioned Constitution Officiorum: All those who have obtained an apostolic faculty to read and keep forbidden books, are not thereby authorised to read books and periodicals forbidden by the local Ordinaries, unless the apostolic faculty expressly concedes permission to read and keep books condemned by anybody.

52. But it is not enough to hinder the reading and the sale of bad books – it is also necessary to prevent them from being printed. Hence let the Bishops use the utmost severity in granting permission to print. Under the rules of the Constitution Officiorum, many publications require the authorisation of the Ordinary, and in some dioceses it has been made the custom to have a suitable number of official censors for the examination of writings. We have the highest praise for this institution, and We not only exhort, but We order that it be extended to all dioceses. In all episcopal Curias, therefore, let censors be appointed for the revision of works intended for publication, and let the censors be chosen from both ranks of the clergy – secular and regular – men of age, knowledge and prudence who will know how to follow the golden mean in their judgments. It shall be their office to examine everything which requires permission for publication according to Articles XLI. and XLII. of the above-mentioned Constitution. The Censor shall give his verdict in writing. If it be favourable, the Bishop will give the permission for publication by the wordImprimatur, which must always be preceded by the Nihil obstat and the name of the Censor. In the Curia of Rome official censors shall be appointed just as elsewhere, and the appointment of them shall appertain to the Master of the Sacred Palaces, after they have been proposed to the Cardinal Vicar and accepted by the Sovereign Pontiff. It will also be the office of the Master of the Sacred Palaces to select the censor for each writing. Permission for publication will be granted by him as well as by the Cardinal Vicar or his Vicegerent, and this permission, as above prescribed, must always be preceded by the Nihil obstat and the name of the Censor. Only on very rare and exceptional occasions, and on the prudent decision of the bishop, shall it be possible to omit mention of the Censor. The name of the Censor shall never be made known to the authors until he shall have given a favourable decision, so that he may not have to suffer annoyance either while he is engaged in the examination of a writing or in case he should deny his approval. Censors shall never be chosen from the religious orders until the opinion of the Provincial, or in Rome of the General, has been privately obtained, and the Provincial or the General must give a conscientious account of the character, knowledge and orthodoxy of the candidate. We admonish religious superiors of their solemn duty never to allow anything to be published by any of their subjects without permission from themselves and from the Ordinary. Finally We affirm and declare that the title of Censor has no value and can never be adduced to give credit to the private opinions of the person who holds it.

53. Having said this much in general, We now ordain in particular a more careful observance of Article XLII. of the above-mentioned Constitution Officiorum. It is forbidden to secular priests, without the previous consent of the Ordinary, to undertake the direction of papers or periodicals. This permission shall be withdrawn from any priest who makes a wrong use of it after having been admonished. With regard to priests who are correspondents or collaborators of periodicals, as it happens not unfrequently that they write matter infected with Modernism for their papers or periodicals, let the Bishops see to it that this is not permitted to happen, and, should they fail in this duty, let the Bishops make due provision with authority delegated by the Supreme Pontiff. Let there be, as far as this is possible, a special Censor for newspapers and periodicals written by Catholics. It shall be his office to read in due time each number after it has been published, and if he find anything dangerous in it let him order that it be corrected. The Bishop shall have the same right even when the Censor has seen nothing objectionable in a publication.

54. We have already mentioned congresses and public gatherings as among the means used by the Modernists to propagate and defend their opinions. In the future Bishops shall not permit Congresses of priests except on very rare occasions. When they do permit them it shall only be on condition that matters appertaining to the Bishops or the Apostolic See be not treated in them, and that no motions or postulates be allowed that would imply a usurpation of sacred authority, and that no mention be made in them of Modernism, presbyterianism, or laicism. At Congresses of this kind, which can only be held after permission in writing has been obtained in due time and for each case, it shall not be lawful for priests of other dioceses to take part without the written permission of their Ordinary. Further no priest must lose sight of the solemn recommendation of Leo XIII.: Let priests hold as sacred the authority of their pastors, let them take it for certain that the sacerdotal ministry, if not exercised under the guidance of the Bishops, can never be either holy, or very fruitful or respectable (Lett. Encyc. Nobilissima Gallorum, 10 Feb., 1884).

55. But of what avail, Venerable Brethren, will be all Our commands and prescriptions if they be not dutifully and firmly carried out? And, in order that this may be done, it has seemed expedient to Us to extend to all dioceses the regulations laid down with great wisdom many years ago by the Bishops of Umbria for theirs.

“In order,” they say, “to extirpate the errors already propagated and to prevent their further diffusion, and to remove those teachers of impiety through whom the pernicious effects of such dif fusion are being perpetuated, this sacred Assembly, following the example of St. Charles Borromeo, has decided to establish in each of the dioceses a Council consisting of approved members of both branches of the clergy, which shall be charged the task of noting the existence of errors and the devices by which new ones are introduced and propagated, and to inform the Bishop of the whole so that he may take counsel with them as to the best means for nipping the evil in the bud and preventing it spreading for the ruin of souls or, worse still, gaining strength and growth” (Acts of the Congress of the Bishops of Umbria, Nov. 1849, tit 2, art. 6). We decree, therefore, that in every diocese a council of this kind, which We are pleased to name “the Council of Vigilance,” be instituted without delay. The priests called to form part in it shall be chosen somewhat after the manner above prescribed for the Censors, and they shall meet every two months on an appointed day under the presidency of the Bishop. They shall be bound to secrecy as to their deliberations and decisions, and their function shall be as follows: They shall watch most carefully for every trace and sign of Modernism both in publications and in teaching, and, to preserve from it the clergy and the young, they shall take all prudent, prompt and efficacious measures. Let them combat novelties of words remembering the admonitions of Leo XIII. (Instruct. S.C. NN. EE. EE., 27 Jan., 1902): It is impossible to approve in Catholic publications of a style inspired by unsound novelty which seems to deride the piety of the faithful and dwells on the introduction of a new order of Christian life, on new directions of the Church, on new aspirations of the modern soul, on a new vocation of the clergy, on a new Christian civilisation. Language of this kind is not to be tolerated either in books or from chairs of learning. The Councils must not neglect the books treating of the pious traditions of different places or of sacred relics. Let them not permit such questions to be discussed in periodicals destined to stimulate piety, neither with expressions savouring of mockery or contempt, nor by dogmatic pronouncements, especially when, as is often the case, what is stated as a certainty either does not pass the limits of probability or is merely based on prejudiced opinion. Concerning sacred relics, let this be the rule: When Bishops, who alone are judges in such matters, know for certain the a relic is not genuine, let them remove it at once from the veneration of the faithful; if the authentications of a relic happen to have been lost through civil disturbances, or in any other way, let it not be exposed for public veneration until the Bishop has verified it. The argument of prescription or well-founded presumption is to have weight only when devotion to a relic is commendable by reason of its antiquity, according to the sense of the Decree issued in 1896 by the Congregation of Indulgences and Sacred Relics: Ancient relics are to retain the veneration they have always enjoyed except when in individual instances there are clear arguments that they are false or suppositions. In passing judgment on pious traditions be it always borne in mind that in this matter the Church uses the greatest prudence, and that she does not allow traditions of this kind to be narrated in books except with the utmost caution and with the insertion of the declaration imposed by Urban VIII, and even then she does not guarantee the truth of the fact narrated; she simply does but forbid belief in things for which human arguments are not wanting. On this matter the Sacred Congregation of Rites, thirty years ago, decreed as follows:These apparitions and revelations have neither been approved nor condemned by the Holy See, which has simply allowed that they be believed on purely human faith, on the tradition which they relate, corroborated by testimonies and documents worthy of credence (Decree, May 2, 1877). Anybody who follows this rule has no cause for fear. For the devotion based on any apparition, in as far as it regards the fact itself, that is to say in as far as it is relative, always implies the hypothesis of the truth of the fact; while in as far as it is absolute, it must always be based on the truth, seeing that its object is the persons of the saints who are honoured. The same is true of relics. Finally, We entrust to the Councils of Vigilance the duty of overlooking assiduously and diligently social institutions as well as writings on social questions so that they may harbour no trace of Modernism, but obey the prescriptions of the Roman Pontiffs.

56. Lest what We have laid down thus far should fall into oblivion, We will and ordain that the Bishops of all dioceses, a year after the publication of these letters and every three years thenceforward, furnish the Holy See with a diligent and sworn report on all the prescriptions contained in them, and on the doctrines that find currency among the clergy, and especially in the seminaries and other Catholic institutions, and We impose the like obligation on the Generals of Religious Orders with regard to those under them.

57. This, Venerable Brethren, is what we have thought it our duty to write to you for the salvation of all who believe. The adversaries of the Church will doubtless abuse what we have said to refurbish the old calumny by which we are traduced as the enemy of science and of the progress of humanity. In order to oppose a new answer to such accusations, which the history of the Christian religion refutes by never failing arguments, it is Our intention to establish and develop by every means in our power a special Institute in which, through the co-operation of those Catholics who are most eminent for their learning, the progress of science and other realms of knowledge may be promoted under the guidance and teaching of Catholic truth. God grant that we may happily realise our design with the ready assistance of all those who bear a sincere love for the Church of Christ. But of this we will speak on another occasion.

58. Meanwhile, Venerable Brethren, fully confident in your zeal and work, we beseech for you with our whole heart and soul the abundance of heavenly light, so that in the midst of this great perturbation of men’s minds from the insidious invasions of error from every side, you may see clearly what you ought to do and may perform the task with all your strength and courage. May Jesus Christ, the author and finisher of our faith, be with you by His power; and may the Immaculate Virgin, the destroyer of all heresies, be with you by her prayers and aid. And We, as a pledge of Our affection and of divine assistance in adversity, grant most affectionately and with all Our heart to you, your clergy and people the Apostolic Benediction.

It is easy to see that much of this has the effect of penalizing an attitude or various attitudes, regardless of whether a person’s actual beliefs are in conformity with Catholic doctrine or not. This would be the effect of talking about people “imbued with Modernism,” people who “favour Modernism,” “criticizing scholasticism,” “show a love of novelty,” “a style inspired by unsound novelty,” and the like. None of these things are about particular opinions of any kind, but about attitudes, and ones where it may well be unclear whether or not someone has them.

The problem with all of this, of course, is that you cannot resolve people’s doubt and uncertainty by making laws against it. This method simply does not work. And a great deal of Pius X’s concern is in fact about such doubt and uncertainty, and not about particular opinions contrary to Catholic doctrine.

Some of the modernists asserted that Pascendi condemned Newman’s theory of the development of doctrine. Pius X explicitly denied this:

Venerable Brother, greetings and Our Apostolic blessing. We hereby inform you that your essay, in which you show that the writings of Cardinal Newman, far from being in disagreement with Our Encyclical Letter Pascendi, are very much in harmony with it, has been emphatically approved by Us: for you could not have better served both the truth and the dignity of man. It is clear that those people whose errors We have condemned in that Document had decided among themselves to produce something of their own invention with which to seek the commendation of a distinguished person. And so they everywhere assert with confidence that they have taken these things from the very source and summit of authority, and that therefore We cannot censure their teachings, but rather that We had even previously gone so far as to condemn what such a great author had taught. Incredible though it may appear, although it is not always realised, there are to be found those who are so puffed up with pride that it is enough to overwhelm the mind, and who are convinced that they are Catholics and pass themselves off as such, while in matters concerning the inner discipline of religion they prefer the authority of their own private teaching to the pre-eminent authority of the Magisterium of the Apostolic See. Not only do you fully demonstrate their obstinacy but you also show clearly their deceitfulness. For, if in the things he had written before his profession of the Catholic faith one can justly detect something which may have a kind of similarity with certain Modernist formulas, you are correct in saying that this is not relevant to his later works. Moreover, as far as that matter is concerned, his way of thinking has been expressed in very different ways, both in the spoken word and in his published writings, and the author himself, on his admission into the Catholic Church, forwarded all his writings to the authority of the same Church so that any corrections might be made, if judged appropriate. Regarding the large number of books of great importance and influence which he wrote as a Catholic, it is hardly necessary to exonerate them from any connection with this present heresy. And indeed, in the domain of England, it is common knowledge that Henry Newman pleaded the cause of the Catholic faith in his prolific literary output so effectively that his work was both highly beneficial to its citizens and greatly appreciated by Our Predecessors: and so he is held worthy of office whom Leo XIII, undoubtedly a shrewd judge of men and affairs, appointed Cardinal; indeed he was very highly regarded by him at every stage of his career, and deservedly so. Truly, there is something about such a large quantity of work and his long hours of labour lasting far into the night that seems foreign to the usual way of theologians: nothing can be found to bring any suspicion about his faith. You correctly state that it is entirely to be expected that where no new signs of heresy were apparent he has perhaps used an off-guard manner of speaking to some people in certain places, but that what the Modernists do is to falsely and deceitfully take those words out of the whole context of what he meant to say and twist them to suit their own meaning. We therefore congratulate you for having, through your knowledge of all his writings, brilliantly vindicated the memory of this eminently upright and wise man from injustice: and also for having, to the best of your ability, brought your influence to bear among your fellow-countrymen, but particularly among the English people, so that those who were accustomed to abusing his name and deceiving the ignorant should henceforth cease doing so. Would that they should follow Newman the author faithfully by studying his books without, to be sure, being addicted to their own prejudices, and let them not with wicked cunning conjure anything up from them or declare that their own opinions are confirmed in them; but instead let them understand his pure and whole principles, his lessons and inspiration which they contain. They will learn many excellent things from such a great teacher: in the first place, to regard the Magisterium of the Church as sacred, to defend the doctrine handed down inviolately by the Fathers and, what is of highest importance to the safeguarding of Catholic truth, to follow and obey the Successor of St. Peter with the greatest faith. To you, therefore, Venerable Brother, and to your clergy and people, We give Our heartfelt thanks for having taken the trouble to help Us in Our reduced circumstances by sending your communal gift of financial aid: and in order to gain for you all, but first and foremost for yourself, the gifts of God’s goodness, and as a testimony of Our benevolence, We affectionately bestow Our Apostolic blessing.

Pius X is certainly right that Newman’s theory of development is quite different from the modernist system which he condemns in Pascendi. Nonetheless, there is a real relationship between the two, and much more is there one between Newman’s theory and people’s uncertainty and doubt.

The difference, of course, is that the evolution of doctrine which is condemned in Pascendi is the first theory Newman mentions, which tends to imply the absence of a real revelation, and which Ross Douthat says is a view that “sounds like heresy by any reasonable definition of the term.” In this sense, Newman’s theory of development is quite different. However, there is a relationship, because Newman admits the possibility of changes in doctrine, without positively establishing any absolute limits on the possibility.

By doing this, Newman’s theory in itself tends to be a cause of “doubt and uncertainty,” even when it is taken in a Catholic sense. The Catholic interpretation would imply that the substance of a doctrine must remain unchanged. But since all claims are vague, and changes of opinion happen in a vague and slow way, the line between a development of doctrine and a substantial change in doctrine will necessarily be a vague line, just like the line between a man who is bald and a man who is not. This will necessarily cause doubt about whether various changes would constitute a substantial change of doctrine or not, and therefore about whether or not certain opinions, currently rejected by the Church or by most of it, might turn out to be true.