The crucial decree at the Council of Constance, in Francis Oakley’s story, is Haec Sancta, part of which reads (and according to the Vatican website contradicts Vatican I on “papal primacy/infallibility”):
In the name of the holy and undivided Trinity, Father and Son and holy Spirit. Amen. This holy synod of Constance, which is a general council, for the eradication of the present schism and for bringing unity and reform to God’s church in head and members, legitimately assembled in the holy Spirit to the praise of almighty God, ordains, defines, decrees, discerns and declares as follows, in order that this union and reform of God’s church may be obtained the more easily, securely, fruitfully and freely.
First it declares that, legitimately assembled in the holy Spirit, constituting a general council and representing the catholic church militant, it has power immediately from Christ; and that everyone of whatever state or dignity, even papal, is bound to obey it in those matters which pertain to the faith, the eradication of the said schism and the general reform of the said church of God in head and members.
Next, it declares that anyone of whatever condition, state or dignity, even papal, who contumaciously refuses to obey the past or future mandates, statutes, ordinances or precepts of this sacred council or of any other legitimately assembled general council, regarding the aforesaid things or matters pertaining to them, shall be subjected to well-deserved penance, unless he repents, and shall be duly punished, even by having recourse, if necessary, to other supports of the law. (quoted in Oakley, 83)
This affirmation of conciliarism was designed to address the unity of the church, one of the true church’s four marks:
Of the four marks of the Church designated in the Nicene Creed — one, holy, Catholic, apostolic — the mark of holiness had appeared earlier and more frequently in the various creeds than had the other three. And it was also the characteristic that had given rise to some of the earliest ecclesiological controversies. But in the great late medieval tide of debate concerning the nature of the Church that was to crest during the conciliar epoch, it was less the mark of holiness than that of unity that lay at the very heart of disagreement. If, for adherents to the more prominent high-papalist position, the key to that unity lay in the firm subordination of all the members of the Christian community to a single papal head, for others the key lay, rather, in the corporate association of those members. It was from the latter group that the conciliarists of the late fourteenth and fifteenth centuries took their cue. Committed to the belief that the papal headship of the Church was indeed of divine foundation, but more also it seems, by memories of what today would be called the ecclesiology of communio and by the scriptural and patristic vision of the community of Christians as forming a single body with Christ, it’s ‘primary’ or ultimate head, the proponents of conciliarist views sought to combine those two convictions. That is to say, and as J. H. Burns has rightly insisted, their argument with the high papalists was not an argument “for or against [papal] monarchy as such’, but an argument about the nature of that papal monarchy. For they sought to harmonize their twin convictions by insisting that side by side with the institution of papal monarchy it was necessary to give the Church’s communitarian or corporate dimension more prominent and routine institutional expression, most notably by the regular assembly of general councils representing the entire community of the faithful. (65)
In other words, the conciliarists were looking perhaps more for an arrangement like that of the Church of England, with an archbishop in Canterbury who presides over all the bishops but is the first among equals and meets every decade at the Lambeth Conference. Of course, this is not an argument for presbyteries, classes, synods, or assemblies as Reformed Protestants know and convene them. But Oakley’s book does show once again how deficient Jason and the Callers’ understanding of Roman Catholic history is. Papal primacy and its nature has long been a source of debate among Roman Catholics (and still is among American Roman Catholics, with the Americanists wanting the Vatican to loosen up and the conservatives wanting the papacy to instill discipline and order). Papal primacy is not a solution to Protestantism’s problems because it has not solve Roman Catholicism’s problems.
Oakley rounds out his discussion of Haec Sancta by addressing whether it was novel or reactionary in its conciliar convictions. Here he follows the path-breaking work of Brian Tierney:
Prior to 1955, scholars had long pointed out the frequency with which the earlier canon lawyers were cited in the conciliarist tracts, and the growth since the Second World War of interest in the history of medieval canon law helped focus attention on those citations. Insisting that the borrowing from Ockham and Marsiglio to be found in the consiliarist tracts usually reflected the use to which those two authors had themselves made of the canon law, Tierney argues that the strict conciliar theory, far from being a reaction against canonistic teaching or an alien importation onto ecclesial soil of secular constitutional notions, had instead deep (and impeccably orthodox) roots in the ecclesiological tradition of the pre-Marsiglian era. It unquestionably drew a great deal of inspiration from the communio ecclesiology and synodal practice of the first millennium of Christian life, and especially from the essentially concilar mode of governance that had characterized the ancient Church for long centuries after the Council of Niceaea (325). That phase of Church history had left as its enduring legacy not only the doctrinal decrees and disciplinary canons of the great ecumenical councils but also the memory of the work accomplished by a whole series of pivotal provincial councils, prominent among them those held at Toledo in Visigothic Spain. . . .
What this soluation to the problem of origins means, of course, is that conciliar theory did not represent (as Figgis and others assumed) some sort of radical intrusion — in Tierney’s words, ‘something accidental external, thrust upon the Church from the outside’. It was, instead, ‘a logical culmination of ideas that were [deeply] embedded in the law and doctrines of the Church itself. (106-107, 110)