The principal objection to Anglican orders being valid, according to Leo XIII, was the alleged deficiency of intention and of form of the Anglican ordination rites. In the case of deficiency of intention, the pope declared that the rites expressed an intention to create a priesthood different from the sacrificing priesthood of the Roman Catholic Church and reduce ordination to a mere ecclesiastical institution, an appointment or blessing, instead of a sacramental conferral of actual grace by the action itself.
The view of many Anglican bishops and apologists was that the required references to the sacrificial priesthood never existed in many ancient Latin Rite ordination liturgies or in certain Eastern Rite ordination liturgies which the Roman Catholic Church considered to be valid. Many Roman Catholic apologists, including English bishops, asserted that those Eastern Rite forms adequately described the powers proper to a bishop, including his supreme priesthood and the ordination of priests, deacons and subdeacons, thus confirming the true intention and meaning of the rite.
Prior to Apostolicae Curae, decisions had already been given by Rome that the Anglican orders orders were invalid. The practices of the Roman Catholic Church had supposed their invalidity. Whenever former Anglican priests desired to be priests in the Roman Catholic Church they were unconditionally ordained. As the Oxford Movement progressed, several members of the clergy and laity of the Church of England argued that the practice of the Roman Catholic Church unconditionally ordaining clerical converts from Anglicanism arose out of a lack of inquiry into the validity of Anglican orders and from mistaken assumptions which, in the light of certain historical investigations, could no longer be asserted.
Those who were interested in a corporate reunion of Rome and Canterbury thought that, as a condition to such reunion, Anglican orders might be accepted as valid by the Roman Catholic Church. A few Roman Catholic writers thought that there was at least room for doubt and joined with them in seeking a fresh inquiry into the question and an authoritative judgment from Pope Leo XIII. The pope permitted the question to be re-examined. He commissioned a number of men, whose opinions on the matter were known to be divergent, to state the grounds for his judgment in writing. He then summoned them to Rome and directed them to exchange writings. The pope placed at their disposal all the documents available and directed them to further investigate and discuss the matter. Thus prepared, he ordered them to meet in special sessions under the presidency of a cardinal appointed by him. Twelve such sessions were held in which "all were invited to free discussion". He then directed that the acts of those sessions, together with all the documents, should be submitted to a council of cardinals, "so that when all had studied the whole subject and discussed it in Our presence each might give his opinion". The final result was the Papal bull Apostolicae Curae, in which Anglican orders were declared to be invalid. The bull was issued 15 September 1896 and declared Anglican orders to be "absolutely null and utterly void". The bull explained at length that the decision rested on extrinsic and on intrinsic grounds.
When the reconciliation of the Church of England with the Holy See took place in the reign of Queen Mary, Pope Julius III sent Reginald Cardinal Pole as Legate to England with powers to meet the case. Those powers were "certainly not intended to deal with an abstract state of things, but with a specific and concrete issue." They were directed towards providing for holy orders in England "as the recognized condition of the circumstances and the times demanded." The powers given to Cardinal Pole on 8 March 1554 distinguished two classes of priests: "the first, those who had really received sacred orders, either before the secession of Henry VIII, or, if after it and by ministers infected by error and schism, still according to the accustomed Catholic Rite; the second, those who were initiated according to the Edwardine Ordinal, who on that account could be promoted, since they had received an ordination that was null." The mind of Julius III appears also from the letter dated 29 January 1555 by which Cardinal Pole delegated his powers to the Bishop of Norwich. To the same effect was a bull issued by Pope Paul IV on 20 June 1555 and a brief dated 30 October 1555. Apostolicae Curae also cites John Clement Gordon who had received orders according to the Edwardine Ritual. Pope Clement XI issued a decree on 17 April 1704 that he should be ordained unconditionally and he grounded his decision on the "defect of form and intention".
The same was held to be true of episcopal consecration. The episcopate is thought to constitute the priesthood in the highest degree. It was concluded that the true priesthood was utterly eliminated from the Anglican rite and the priesthood was in no way conferred truly and validly in the episcopal consecration of the same rite. For the same reason the episcopate was in no way truly and validly conferred by it and this the more so because among the first duties of the episcopate is that of ordaining ministers for the Holy Eucharist.
The pope went on to state that the Anglican ordinal had included what he felt were the errors of the English Reformation. It could not be used to confer valid orders, nor could it later be purged of this original defect, chiefly because he felt the words used in it had a meaning entirely different from what would be required to confer the sacrament. The pope felt that not only was the proper form for the sacrament lacking in the Anglican ordinal, but the intention was also lacking. He concluded by explaining how carefully and how prudently this matter has been examined by the Holy See. He stated that those who examined it with him were agreed that the question had already been settled, but that it might be reconsidered and decided in the light of the latest controversies over the question. He then declared that ordinations conducted with the Anglican rite were "null and void", and implored those who were not Roman Catholic and who wanted orders to return to the one sheepfold of Christ where they would find the true aids for salvation. He also invited those who were the ministers of religion in their various congregations to be reconciled to the Roman Catholic Church, assuring them of his sympathy in their spiritual struggles. The bull concludes with the usual declaration of the authority of an apostolic letter.
According to the Anglican view, the required references to the sacrificial priesthood never existed in many ancient Catholic ordination liturgies, and also in certain current Eastern Rite ordination liturgies which the Roman Catholic Church considered to be valid. Frederick Temple, Archbishop of Canterbury, and William Dalrymple Maclagan, Archbishop of York, answered Pope Leo's charges in their written response, Saepius Officio: Answer of the Archbishops of Canterbury and York to the bull Apostolicae Curae of H.H. Leo XIII. It was written to prove the sufficiency of the form and intention used in the Anglican ordinal rites since the time of the English Reformation. In it they discounted the charges levelled against the Church of England, claiming that Rome was ill-informed or wilfully ignorant of both historical occurrence and also the ancient liturgies of both the English and ancient Roman Churches.
First, they asserted that the ordination ceremonies in question were biblically valid. They then provided pages of quotations, detailing Roman and Orthodox liturgies guilty of the same alleged offenses. According to the archbishops, if the ordinations of the bishops and priests in the Anglican Communion were invalid then, by the same measure, so must be the ordinations of clergy in the Roman Catholic and the Orthodox Churches.
On the charge of intent, the response argued that the readmission of the required phrases in 1662 were addressed more to the Presbyterian rather than the Roman controversy. They asserted also that the Book of Common Prayer as a whole contained a strong sacrificial theology in the ordinal. They agreed that, at the time of the reunion of the churches under Queen Mary, many Edwardian priests were deprived for various reasons. They then demonstrated that not one priest was deprived on account of defect of order. Some were voluntarily reordained and others received anointing as a supplement to their previous ordination. Some, and perhaps the majority, remained in their benefices without reordination. In some cases, Edwardian priests were promoted to higher positions in the Roman Catholic Church. They argued against the pope's example of John Clement Gordon, stating that - among other things - Gordon's desire for reordination had its roots in the discredited Nag's Head Fable.
Another Anglican view was that of Randall Davidson, who later became Archbishop of Canterbury. He stressed “the strength and depth of the Protestantism of England” and regarded other differences with Rome as much more important than its views on Anglican orders. This view seems to have been widely held at the time, judging from the reaction of Herbert Cardinal Vaughan, Roman Catholic Archbishop of Westminster. He was somewhat surprised that the pope's decision was so well received in England.
Helped by articles in The Times, Apostolicae Curae was understood to mean that orders conferred in the Church of England were not, to the pope, orders in the Roman Catholic sense. Anglican resentment began to abate. Cardinal Vaughan's biographer comments that, “there would probably have been much more resentment had the Holy See declared in favour of Anglican orders and declared Anglican clergy ‘massing priests’”. . However Vaughan was quick to publish in 1898 "A Vindication of the Bull 'Apostolicae Curae' by the Cardinal Archbishop and Bishops of the Province of Westminster".
Looking at the Edwardian ordinal, Dix found sufficient mention of the priesthood in the service, the actual formula at the laying on of hands being concerned not only with the priestly act of forgiving sins but also with administering the sacraments and sufficient mention of intention in the prefaces to the ordination rites, to make it impossible to believe that the priesthood was not being conferred and the traditional ministry continued. Nevertheless he concluded by arguing that if Anglican authority committed itself to unity schemes which equated Anglican orders with those of Methodists and other Protestants, then their action would justify Leo XIII and declare Apostolicae Curae to be right.
Writing in The Tablet, a prominent Roman Catholic weekly magazine, Timothy Dufort argued that “a way is open for the recognition of the Orders held in the Church of England today without the necessity of contradicting Pope Leo XIII”. He argues that the present BCP wording introduced in the 1662 Ordinal signifies the orders being bestowed in the clearest of terms and would meet Leo's requirements while that of 1552 and 1559 did not. Furthermore the answer of the archbishops in his view has in itself removed another obstacle as it shows an intention on the part of the archbishops which is clearly adequate by the tests of Trent and the Holy Office. The final obstacle, the gap between 1552 and 1662, to which Pope Leo refers, has also disappeared. Old Catholic bishops, recognised as valid by Rome, have acted as co-consecrators in episcopal consecrations with Anglicans. By 1969, Dufort argued all Anglican bishops are now also in the Old Catholic succession. He argued Apostolicae Curae had been overtaken by events.
In more recent times the Reverend John Jay Hughes, amongst a few other Roman Catholic writers, have concluded that there were enough flaws in and ambiguity surrounding the pope’s apostolic letter that the question of the invalidity of Anglican holy orders allegedly merited re-examination. Father Hughes himself had previously been an Anglican priest and was subsequently conditionally (sub conditione) ordained in the Roman Catholic Church. Other Anglican theological critics argue that apostolic succession had never been broken in the first place, due to valid ordinations tracing back to Archbishop Laud and beyond to Archbishop Parker.
The late Cardinal Basil Hume, Roman Catholic Archbishop of Westminster (London, England), suggested that the conclusions of Apostolicae Curae can only relate to the situation in 1896 and that the involvement of Old Catholic bishops in Anglican ordinations since the Bonn Agreement in the 20th century, along with changes of the consecratory prefaces, have re-established apostolic succession within Anglicanism. Archbishop Hume said in 1978:
I could not in practice dismiss all Anglican Orders as "null and void" because I know that a number of Anglican Bishops have in fact had the presence at their ordination of an Old Catholic or an Orthodox bishop, that is, somebody who, in the traditional theology of our Church, has been ordained according to a valid rite.
As far as the Roman Catholic Church is concerned, I think it needs to look carefully again at Apostolicae Curae and its status. We need to discover whether the historical background upon which it was working and the argumentation upon which it was based is consonant with historical and theological truth as theologians and historians see it today.
By 1994 his opinion was that doubts could exist about the invalidity of certain Anglican ordinations:
While firmly restating the judgment of Apostolicae Curae that Anglican ordination is invalid, the Catholic Church takes account of the involvement, in some Anglican episcopal ordinations, of bishops of the Old Catholic Church of the Union of Utrecht who are validly ordained. In particular and probably rare cases the authorities in Rome may judge that there is a "prudent doubt" concerning the invalidity of priestly ordination received by an individual Anglican minister ordain in this line of succession.
There are many complex factors which would need to be verified in each case... Of course, if there were other cases where sufficient evidence was available, the balance of that evidence may lead the authorities to reach a different judgment.
In 1998 Joseph Cardinal Ratzinger (then Prefect of the Congregation for the Doctrine of the Faith, and later Pope Benedict XVI) issued a doctrinal commentary to accompany Pope John Paul II’s apostolic letter Ad Tuendam Fidem, which established penalties in Canon law for failure to accept “definitive teaching”. Despite the ongoing work of the ecumenical Anglican Roman Catholic International Commission (ARCIC), Ratzinger’s commentary listed Leo XIII’s declaration in Apostolicae Curae that Anglican orders are “absolutely null and utterly void” as one of the teachings to which Catholics must give “firm and definitive assent”. These teachings are not understood by the Church as revealed doctrines but are rather those which the church’s teaching authority finds to be so closely connected to God's revealed truth that belief in them is required in order to safeguard the divinely revealed truths of the Christian Faith. Those who fail to give “firm and definitive assent”, according to the commentary, would “no longer be in full communion with the Catholic Church”.
Similarly, the decision of some Anglican bodies to extend intercommunion to churches without the traditional understanding of apostolic succession, such as various Lutheran churches, may also indicate a breaking with apostolic teaching and practice according to the Roman Catholic Church. While the 1999 Concordat between the Episcopal Church and the Evangelical Lutheran Church in America calls for Episcopal Church bishops to participate in the consecration of ELCA Lutheran bishops, the agreement did not require the re-ordination of all Lutheran bishops and ministers. This was done so that ELCA ministers ordained by these ELCA bishops could serve in the Episcopal Church.