We are all bound to accept authoritative docuмents by the magisterium. And to reinforce this I will share an article by Monsignor Fenton that was devoted to this topic alone:

There is one section of the Holy Father's encyclical Humani generis which has aroused a special deal of attention in our own country. It is the following paragraph, the one numbered "20" both in the NCWC translation and in the Latin text which was printed in last November's issue of AER.

Nor must it be thought that what is expounded in Encyclical Letters does not of itself demand consent, since in writing such letters the Popes do not exercise the supreme power of their teaching authority. For these matters are taught with the ordinary teaching authority, of which it is true to say: "He who heareth you, heareth me"; and generally what is expounded and inculcated in Encyclical Letters already for other reasons appertains to Catholic doctrine. But if the Supreme Pontiffs in their official docuмents purposely pass judgment on a matter up to that time under dispute, it is obvious that that matter, according to the mind and will of the same Pontiffs, cannot be any longer considered a question open to discussion among theologians. [This paragraph is found on p. 10 of the NCWC translation. The Latin original of this paragraph in printed in AER, CXXIII, 5 (Nov. 1950), 389.]

Each sentence of this paragraph contains an important theological truth. The first expresses a sometimes obscured fact about the Holy Father's teaching activity. The second sentence brings out a truth which has not hitherto been set down very frequently in that section of theological writing dealing with the Holy Father's teaching power. It constitutes a striking contribution to theological literature. The third stands as a necessary inference from the first and second sentences. It has definite and intensely practical implications for present day theologians.

The first statement of this paragraph condemns any minimizing of the authority of papal encyclicals which might be based on the subterfuge that the Holy Father does not use the fullness of his doctrinal power in such docuмents. The teaching of the encyclicals postulates an assensum per se, an acceptance by Catholics precisely because it is the teaching of the supreme doctrinal authority within the universal Church of Jesus Christ on earth. It demands such acceptance even when the Holy Father does not use supremam sui Magisterii potestatem. In other words, Catholics are bound to tender, not merely a courteous acknowledgment, but a genuine and sincere inward acceptance, to teachings which the Holy Father sets forth with a note or qualification less than de fide or even doctrina certa.

It is impossible to see the full meaning of this teaching without having an accurate understanding of what constitutes the suprema magisterii potestas of the Roman Pontiff. Here two distinct misconceptions must be avoided. The suprema magisterii potestas is in no way limited to the solemn teaching activity of the Holy Father, to the exclusion of the doctrinal pronouncements he makes in the ordinary manner. Neither is it in any way restricted to the primary object of the Church's doctrinal competence, to the exclusion of those truths which lie within what is known as the secondary object of the Church's infallible teaching power. The Holy Father actually exercises his suprema magisterii potestas whenever he issues an infallible or irrevocable doctrinal decision or pronouncement binding upon the universal Church militant. The mode or manner of such a pronouncement may be either solemn or extraordinary or ordinary. He may speak within the field of the primary object of the Church's infallible teaching power, or within that of the secondary object. In any case, where the decision is final and is addressed to and binding upon the universal Church militant, the utterance is an exercise of the suprema magisterii potestas. This holds true, we must remember, whether the statement be one of the solemn judgment or the ordinary magisterium.

The first declaration presupposes that docuмents or statements in which the Holy Father uses his suprema magisterii potestas demand acceptance by all Christians, and that such acceptance is due to these pronouncements by reason of the authority or weight of the pronouncements themselves. To this presupposition it adds the declaration that the papal encyclicals (and similar writings or oral statements addressed by the Holy Father directly or indirectly to the universal Church militant) demand a genuine acceptance on the part of Christians even where the suprema magisterii potestas is not employed.

In other words, the Humani generis here renews the Church's teaching that the Holy Father is empowered, not only to obligate the disciples of Jesus Christ to accept, on faith or as certain, statements within the sphere of the Church's doctrinal competence, but also to impose the duty of accepting other propositions within this same sphere as opinions. The Roman Pontiff's commission and responsibility in the doctrinal line within the true Church are such as to demand the power to command doctrinal assent from the faithful for propositions which he teaches as less than certain, or as less than de fide. It lies within the power, and sometimes within the duty of the Roman Pontiff to command his people to assent to propositions which he himself presents as statements which eventually could be abandoned.

Basically, there is nothing new in this concept. The Sovereign Pontiffs have frequently stigmatized statements with a doctrinal censure less severe than that of heresy, and less severe than that of error. It has always been recognized as a fact that Catholics are obliged in conscience to accept these condemnations, and to reject the proscribed propositions inwardly and sincerely. In the last analysis, this process involved the command to adopt an opinion, since the Church, in designating a proposition merely as something rash or ill sounding (to mention only two of these doctrinal censures inferior to those of heresy and error), has not given a definition or completely definitive judgment on the matter in question. The irrevocable decision is to be found only the definitions properly so called, the designation of some propositions as de fide or as certain. Where the declaration is not irrevocable, it is not a definition in the strict sense at all. Properly speaking, such declarations call for an assent which is at once obligatory and opinionative in nature.

The Humani generis thus reasserts the right of the Roman Pontiff to command such an opinionative assent. When, in his encyclicals, or in any other docuмents or utterances of his doctrinal office, he imposes a teaching upon the members of the universal Church militant with anything less than his suprema magisterii potestas, he is calling for such an opinionative judgment. The faithful must, if they are to be loyal in their following of Christ, accept this opinionative judgment as their own. The obligation imposed by the encyclicals is not satisfied when a man merely allows that the teaching set forth in a non-infallible papal pronouncement is a respectable opinion. The followers of Christ, guided by the teaching of Christ which comes to them in the declarations of His Vicar on earth, are bound to take that opinion as their own.

The day may come when that opinion will have to be modified. The Church allows for this possibility when it presents this teaching by other than an irrevocable pronouncement. When that day comes, the ecclesia docens within which Our Lord lives and teaches will realize that the holding of this opinion as it has hitherto been set forth is no longer requisite for the purity of the true faith in the actual circuмstances then existent. Unquestionably the labors of the theologians and the other Catholic scholars throughout the world will have contributed to the formation of that judgment. But, when that judgment comes, it will inevitably be the work, not of separate scholars within the Church, but of the ecclesia docens itself. The voice of Christ the
Teacher within His Church comes to us through the ecclesia docens, and never in opposition to it.

Actually, it is quite impossible to grasp the meaning of this first statement in the twentieth paragraph of the Humani generis unless we take direct cognizance of the fact that Our Lord remains always as the Supreme Teacher within His Church. The authoritative definitions and the declarations of the Catholic Church are not like the resolutions of some mere learned society or professional group. They are the continual doctrinal directions given by Our Lord, through the instrumentality of the ecclesia docens, within His kingdom on earth. They serve to enlighten and guide the disciples of Christ during their period of pilgrimage on this earth in such a way that they may arrive safely in the Church's patria of Heaven. Frequently it would happen that, in an existent status of science or of culture, the acceptance of some opinion or the rejection of another opinion would endanger the integrity of the faith itself among the people of God. It is in such cases that Our Lord, through the instrumentality of His servants in the ecclesia docens, commands His followers to adopt one opinion or to reject another, precisely as an opinion. The modification of these declarations, when and if such modifications ever comes, in no way violates the infallibility of the Church since the doctrine in question was never presented as irrevocable and infallible teaching.

The second sentence in this twentieth paragraph of the encyclical has great importance for modern students of sacred theology. It affirms that the encyclicals are organs of the Holy Father's magisterium ordinarium, and that the promise Our Lord made to His apostles (and through them to their successors in the ecclesia docens) that "He who hears you, hears Me," [Luke, 10: 16.] applies to the magisterium ordinarium just as truly as it applies to the solemn judgments issued by the Holy Father himself or by the ecclesia docens as a whole. This same sentence likewise adds the comment that most of the statements which the faithful are obligated to accept from the encyclicals have already been allocated within the field of Catholic doctrine on some other title. In other words, the Humani generis takes cognizance of the fact that no individual pontifical letter is composed entirely (or even in great part) of assertions which have never before been set forth authoritatively by the ecclesia docens.
 
In a general way, the theological literature dealing with the Church's infallible and authoritative teaching power has tended to restrict the term "ordinary and universal magisterium" to the teachings of the residential bishops of the Catholic Church scattered throughout the world and united with the Roman Pontiff. The terminology of these volumes left little room for any study of the ordinary magisterium of the Roman Pontiff himself. Occasionally we encounter some theological writer careless enough to deny that the Holy Father can teach infallibly other than by solemn judgment or definition. [One writer on theological subjects who made this mistake is Antoine Chevasse, in his essay, "La véritable conception de l'infaillibilité pontificale," in the symposium Église et unite (Lille, 1948, pp. 80ff.] For the most part, however, there is very little comment at all about the Roman Pontiff's magisterium ordinarium. Hence the declaration of the Humani generis to the effect that teaching presented authoritatively (that is, in such a way that Catholics are obliged in conscience to accept it and to adopt it as their own) in the papal encyclicals comes to us by way of the magisterium ordinarium is definitely a contribution to modern theological thought.

The Vatican Council had taught that a dogma of the faith is a truth which the Church finds contained in either of the two sources of divine revelation and which it presents as divine revelation that men must accept as such. It specified that this presentation might be made either in a solemn judgment or by the Church's ordinary and universal magisterium. Most of the manuals took this term "universal" to mean the teaching of the apostolic college of the Catholic Church as it is scattered throughout the world. In other words, they considered the word as applying to a magisterium that was universal in the sense that it was acting over the face of the entire earth at the same time. They acknowledged that such a magisterium universale et ordinarium could be the organ by which a dogma of the Catholic faith might be presented to the people of Jesus Christ, and they pointed to the dogma of the Church's own infallibility as a teaching that is proposed to the members of the Church militant in exactly that fashion.

Now it is a dogma of the Church, presented as such by the Vatican Council itself, that the Holy Father enjoys the same infallibility in defining doctrines about faith and morals that the universal Church (or the entire ecclesia docens) possesses. Thus, since the entire ecclesia docens (the residential bishops of the Catholic Church united with their head, St. Peter's successor in the See of Rome) can define a dogma either in a solemn judgment (when they are gathered together in an oecuмenical council) or in an ordinary manner (when they are actually resident in their own dioceses throughout the world), it follows that the Holy Father himself can speak "ex cathedra" and define a dogma either in solemn judgment (as in cases of the definitions of Our Lady's Immaculate Conception and her glorious bodily Assumption) or by some ordinary means, as, for example, in an encyclical letter.

In such a case, the Holy Father's teaching is universal. He exercises, according to the divine constitution of the Church itself, a true and episcopal jurisdiction over every one of the faithful and over every one of the other pastors within the Church militant. Thus there is nothing whatsoever to prevent the magisterium ordinarium of the Holy Father from being considered precisely as a magisterium universale. It is de fide that the Church's magisterium ordinarium et universale can be the vehicle for the definition and presentation of a Catholic dogma. It is perfectly certain that this same magisterium ordinarium et universale can also be the vehicle or the organ of a definition within the field of the Church's secondary object of infallible teaching. The encyclicals of the Holy Father can be and actually are statements of this magisterium. Hence they can be docuмents in which a dogma is defined or a certain truth of Catholic doctrine (which, however, is not presented precisely as revealed) is brought to the people of God on earth. This is the truth upon which the Humani generis insists at this point. And, since the power to impose authoritatively what may be called an interpretatively conditional assent (an assent which is definitely below the order of real certitude and hence belongs within the field of the opinionative) necessarily accompanies the power to pronounce an infallible judgment, this statement of the Humani generis carries with it the necessary implication that the Holy Father can and does teach authoritatively in his encyclicals when he wishes to impose upon the faithful the obligation of accepting a proposition which he presents neither as de fide nor as theologically certain.

The Humani generis likewise adverts to the fact that, when a person hearkens to the authoritative teaching of the ecclesia docens, that person is actually hearkening to the voice of Our Lord Himself. Once again, it takes this means to remind us that the Church does not teach in this world other than as the instrument and the body of Jesus Christ. The man who quibbles about the Church's doctrinal authority is finding fault, in the last analysis, with the means by which Our Lord brings His divine truth to the children of men. There can be no intelligent appreciation about the Church's magisterium except where and insofar as this paramount fact is taken into consideration.

The last statement of the twentieth paragraph in the Humani generis contains one of the most valuable and important lessons of the entire encyclical. It answers a vitally basic question which must be considered before any practical appreciation of the Church's teaching can be given. The question is this: how can we tell that any statement in a papal encyclical (or in any other docuмent of the Church's magisterium) is one which Catholics are bound in conscience to accept by reason of the authority of the docuмent itself?

The Humani generis does not try to offer anything like a complete answer to this query. It contents itself here with pointing out one instance in which Catholics are definitely and obviously bound in conscience to give an inward assent to the teachings of a papal docuмent. Such an instance occurs, according to the Humani generis, when the Holy Father takes the trouble to issue a pronouncement on a subject which has, up until the issuance of this particular docuмent in which the pronouncement is contained, been considered as open to controversy.

Clearly nothing can be considered as open to question among Catholics where there has been a definite and direct word of the authoritative ecclesiastical magisterium on this subject. Hence the res hactenus controversa to which the Humani generis refers must be a question not as yet decided by the authority of the Holy See or of the ecclesia docens as a whole. The point established in the encyclical is that when the Holy Father, data opera, issues a statement on this matter, it can no longer legitimately be considered as still open to debate among theologians. This remains true even where the sententia pronounced by the Roman Pontiff is not put forward as irrevocable, where, in other words, the contradictory of the teaching asserted is to be condemned with a theological censure less than de fide or erronea.

All that is required in this instance is that the pontifical docuмent should put forward a judgment on a question which has hitherto been considered as undecided, that it should make a definite statement (sententiam ferre) which would be contradictory to or incompatible with some of the opinions previously expressed on this question by theologians. Nothing is said about the necessity of any particular formulae. The intention of the Roman Pontiff to settle the question (either finally and irrevocably, by a declaration that this truth is de fide or at least that it is doctrina certa, or by an interpretatively conditional and opinionative judgment, according to which the contradictory of the teaching given would be qualified as temeraria), is established by the very fact that the Pontiff, in one of his official docuмents or declarations, takes the trouble to make a pronouncement on the subject. Nothing more is needed.

An example of this procedure is to be found in the treatment of the question about the immediate source of episcopal jurisdiction in the Holy Father's encyclical Mystici Corporis. Prior to the appearance of that docuмent there had been many excellent theologians who had contended that the residential bishops of the Catholic Church receive their jurisdictional authority immediately from Our Lord. A greater number of theologians (and writers de iure publico ecclesiastico) held, on the contrary, that these men received their powers from Our Lord through the Roman Pontiff, in such a way that they came immediately from the Holy Father. In the Mystici Corporis, the Pope spoke of the residential bishops' ordinary power of jurisdiction as something "immediate sibi ab eodem Pontifice Summo impertita." That phrase was rightly taken as an indication that the controversy had been settled, once and for all. Where before the teaching that bishops received their power of jurisdiction immediately from the Roman Pontiff had been qualified as "communis," it now became known as "doctrina certa." [Cf. Msgr. Alfredo Ottaviani, in his Institutiones iuris publici ecclesiastici, 3rd edition (Rome: Typis Polyglottis Vaticanis, 1947), I, 413; and also the discussion on this point in AER, CXXI, 3 (Sept. 1949), 210.] The fact that the Sovereign Pontiff had, as it were "gone out of his way," or "taken the trouble," to speak out on a question which had hitherto been regarded as controversial, was taken as an indication that he wished to put an end to the discussion.

In this particular case, the Holy Father expressed himself categorically. Speaking of the bishops' ordinary power of jurisdiction, he qualified it unconditionally as something received immediately from the Sovereign Pontiff. Hence the resulting note was doctrina certa. It would also have been within his power to impose this same teaching as an opinionative judgment, and in this case the censure attached to the contradictory of this teaching would have been ad minus temeraria.
The fact that a question is thus treated by the Roman Pontiff is, according to the Humani generis, an indication that the Holy Father intends that this subject should no longer be considered as a question open to free debate among theologians. The theologians of the Catholic Church have always recognized the fact than an intention on the part of the Holy Father is requisite if the faithful are to be bound by the teaching contained in his official acta. Hitherto, however, there has been too much of a tendency to consider that such an intention would have to be manifested by some sort of formula, as, for instance, by the use of such terms as "define" or "declare." The Humani generis has put an end to this dangerous minimism. Henceforth Catholic theologians have no excuse for not recognizing the fact that a deliberate pontifical statement on a subject which has hitherto been rightly considered as open to debate, takes the matter treated out of this category and makes it a subject on which Catholic writers are bound to accept the judgment of Christ's Vicar on earth.

If the decision of the Holy Father be not irrevocable, the fact that the matter is no longer open to debate does not in any way prevent individual theologians from investigating the subject with a view of working towards a modification of the present Catholic position. There is always at least the absolute possibility that such investigation may eventually result in a modification of the opinion incuмbent upon Catholics by reason of the authority of the Roman Pontiff. It is wrong, however, to teach or to advocate the now reproved position. If the decision is irrevocable, but only in the sense that the Holy Father has placed this teaching within the category of doctrina certa (but not doctrina de fide), then the theologian is free to argue about the possibility of a de fide or dogmatic definition of this point, but he is definitely not free to teach or to hold that the doctrine set forth by the Holy Father can be rejected or modified at all. No teaching is set forth as certain unless it has been defined as true, unless there is no possibility, no fear of danger, that the opposite may turn out to be true.

   The above source of Humani generis and the Holy Father's Ordinary Magisterium is taken from John Lane's Bellarmine Forums. Lastly I'll sum up with the end of another of Monsignor Fenton's articles, Magisterium and Jurisdiction in the Catholic Church:

The great good that comes from an examination of this controversy is a realization of the fact that the teaching of the Catholic Church is authoritative in a unique sense. Ultimately it is Our Lord Himself who teaches within the Church, and the doctrines set forth in His name and by His authority by His ministers demand full acceptance on the part of all subjects of the Church. When the ecclesia docens acts, it inevitably binds the consciences of all Christians to accept its teachings and to manifest that acceptance. It forbids, by the very nature of its activity, any inaccurate statement about the doctrine which has been proposed, or any refusal to receive that doctrine as the personal tenet of the persons to whom it is addressed. The man who rejects that teaching, rejects Our Lord Himself. 
 
Ultimately, we must not allow ourselves to forget, the perfection of the Church's teaching authority is such that the Church itself does not need to add any other jurisdictional act to its authoritative condemnation of some teaching at variance with that doctrine in order to impose upon its subjects the obligation to accept that declaration with a true and inward assent, and in order to forbid, under penalty of offense against God Himself, any outward expression of opposition to what the Church has taught. The teaching power of the Church is inherently and essentially jurisdictional. The man who is subject to the authority of the Church has a duty before God of accepting the acts of the ecclesiastical magisterium with a sincere and genuine inward assent. He is obliged to manifest that acceptance, and to refrain from any oral or written opposition to or misinterpretation of what Our Lord, acting through the ecclesia docens, has proposed authoritatively for his guidance in His Church.

    The above also is from Bellarmine Forums. The Church has repeatedly used her teaching authority to express the fact that it is possible for non-members of the Catholic Church to be saved within that Church. If we refuse to accept this teaching we, in addition to putting ourselves in a dangerous position, put ourselves higher than the Church's magisterium in regards to having the authority to teach and explain divinely revealed truths.