Exequatur (synonymous with REGIUM PLACET), as the Jansenist Van Espen defines it, is a faculty which civil rulers impart to a Bull, papal Brief, or other ecclesiastical enactment in order to give it binding force in their respective territories. This faculty is conceded after ecclesiastical laws have been examined and found not derogatory to any right of the civil power and, therefore, suitable for promulgation. Modern statesmen draw a distinction between the Exequatur and the Regium Placet. The latter, according to them, is given to episcopal acts or acts of any other ecclesiastical superior belonging to the nation for which they are approved; while the former is conceded to enactments of a foreign power, that is, to papal Constitutions; the pope, as head of the whole Church, being formally considered as an authority not belonging to any particular country. In both cases, however, state authorities have the power of examining church laws and giving permission for their promulgation, by which permission ecclesiastical decrees acquire legal value and binding force.
As to the origin of this supposed right of the State over the Church, it is now beyond doubt, contrary to the assertions of Gallicans and Jansenists, that no trace of it can be found in the early centuries of the Church, or even as late as the fourteenth century. It is true that during all that period of time General Councils like those of Nicaea and Ephesus, requisitioned the sanction of State authorities for ecclesiastical laws; it was not, however, juridical, but only physical, force that was then invoked for ecclesiastical decrees, in order to enforce their execution by the secular arm. Moreover, had such a power in the State been at that time known, rulers of nations who were sometimes anxious to prevent the promulgation and execution of papal Constitutions in their domains would have readily appealed to it, instead of resorting to more difficult and troublesome means, in order to impede in every possible way papal letters from ever being introduced into their dominions, e.g. in the conflicts of Philip the Fair of France with Boniface VIII, and of Henry II of England with Alexander.
III. The Regium Placet really dates from the great Western Schism, which lasted from the pontificate of Urban VI to the Council of Constance and the election of Martin V (1378-1417). In order to guard against spurious papal letters issued by antipopes during the schism, Urban VI granted to some ecclesiastical superiors the faculty of examining papal Constitutions and ascertaining their authenticity before promulgation and execution. Civil authorities felt bound to adopt the same precautionary measure, though they did not attribute such a power to themselves as a right attached to their office; apparently its use was discontinued when, after the schism, Martin V condemned the Regium Placet in his Constitution “Quod antidota” (1418). In the fifteenth century, however, it was revived in Portugal by King John II and claimed by him as a right inherent in the crown. In the sixteenth century the Viceroy of Naples, the Duke of Alcala, made it obligatory by law, and in the seventeenth century it was introduced into France in order to preserve the so-called Gallican Liberties, and afterwards into Spain, Belgium, Sicily, Naples, and other countries.
In theory this supposed right of the State was first propounded and defended as a true doctrine by Luther, Pasquier Quesnel, and other heretics who denied the supreme jurisdiction of the pope; later on it was advocated by Gallicans and Jansenists, e.g. Van Espen, Febronius, De Marca, and Stockmans, who attributed this power to the State as a necessary means of self-defense against possible attempts of the Church to injure the rights of civil society. More recently it has been defended with particular vigor by Italian jurists and statesmen, e.g. Cavallari, Mancini, Piola, apropos particularly of the “Law of Guarantees” passed in 1871 by the Italian Government in favor of the Holy See. However, not only is it historically erroneous, as shown above, that such a right has been exercised from time immemorial, but it is also juridically false that such power naturally belongs to the State, particularly as a necessary means of self-defense. The injustice of that claim and the consequent usurpation of authority by the State appear manifest in the light of Catholic faith. If the binding force of church laws depended on the approval and consent of the State, it would no longer be true that the Church received legislative power directly from her Divine Founder, and that whatever is bound or loosed by the Church on earth, will be bound or loosed in heaven (Matt., xvi, 19). Again, the Church would, in that case, immediately cease to be a supreme, self-sufficient, and perfect society, and would be deprived of her characteristics of unity, sanctity, catholicity, and apostolicity. Moreover, the use of the Exequatur to prevent possible usurpation of rights is contrary not only to Divine law but also to natural social law and is, therefore, an abuse of power, even if exercised by a State not professing the Catholic religion. A possible conflict of rights of two societies and the fear of a consequent injury to their respective jurisdiction do not entitle one of them to impede the free exercise of its ordinary jurisdiction by the other. Differences, if they arise may be settled by private mutual understanding or arbitration. It is needless to say that the fear of any usurpation or conflict on the part of the Church is unfounded, as appears from her doctrine and history.
The Church, as a matter of fact, never claimed the power of revising and approving civil laws before promulgation, although, indeed, past experience would justify her in fearing on the part of the State usurpation of her powers. She contents herself with condemning civil laws after promulgation, if they are injurious to Catholic interests. We need not wonder, then, that the Church has always condemned the doctrine and use of the Regium Placet. Boniface IX first condemned it in his Constitution “Intenta Salutis” and after him a great number of pontiffs, down to Pius IX in Propositions 28 and 29 of the Syllabus “Quanta Cura” and in the Allocution “Luctuosis Exagitati” (March 12. 1877), also the Vatican Council in the Constitution “De Ecclesia, Christi”. To avert animosities and persecution, the Church has made minor concessions in favor of the State as to the exercise of the Regium Placet. In some other instances she has tolerated its acknowledgment by ecclesiastics, particularly to enable them to take possession of benefices and other temporalities. At present the Exequatur, or Regium Placet, is seldom, if ever, used, at least in its fullness, by modern civil rulers. In the Kingdom of the Two Sicilies it was abolished by the Concordat of 1818, and in Austria by that of 1855. It must likewise be regarded as abolished in Spain, France, Portugal, and Hungary. According to Aichner, it exists still, but in a mitigated form, in Saxony, Bavaria, and some parts of Switzerland. In Italy the strict Exequatur, i.e. previous to promulgation of papal Constitutions, is not in use, but it is retained in a mild form for the possession of ecclesiastical benefices. According to the “Law of Guarantees” (July 13, 1871), ecclesiastics who have been provided with benefices must present the Bull of their appointment to the State authorities; after approval the latter concede the Exequatur and put the incumbents of benefices in possession of the temporalities hitherto controlled by the government. In this form the Exequatur is at present tolerated by the Church, though it is not devoid of inconveniences, as Leo XIII complained in a letter written to his Secretary of State Cardinal Nina (August 27, 1878).