In early 897, a bizarre event known as the "cadaver synod" occurred in St. John Lateran’s in Rome. The disinterred corpse of Pope Formosus (891–894) was brought before the then-reigning pontiff, Stephen VI (896–897), to be tried on a variety of charges. The use of Formosus’s body in this sort of trial and punishment in "effigy," scandalous to our modern sensibilities, belonged to a different age which had its own views regarding the appropriateness of certain punishments inflicted upon the living and—on occasion—the dead.
Stephen VI found Formosus guilty, then declared his predecessor’s acts and ordinations as pope to be "null" and void. Bishops and priests ordained by Formosus were commanded to be re-ordained if they wished to remain in the ranks of the clergy. A year following Stephen VI’s death, Pope John IX (898–900) held his own synod in which he declared Formosus’s ordinations valid. Pope Sergius III (904–911) fueled the already confusing spectacle by nullifying John IX’s synod, thereby re-instating the former judgments against Formosus and his ordinations.
Not surprisingly, anti-infallibilists have held up the case of Formosus as a contradiction of the doctrine of papal infallibility. The case was raised last century by Ignaz von Döllinger and more recently by former Catholic priest Peter de Rosa (Vicars of Christ: The Dark Side of the Papacy) and by Fundamentalist apologist Dave Hunt (A Woman Rides the Beast). It is alleged the case involves a series of contradictory ex cathedra declarations made by successive popes regarding Formosus’s guilt and the validity of his ordinations. Further, Hunt argues the "nullification" of Formosus’s ordinations has resulted in the interruption of apostolic succession for those "ordained" in line from Formosus. As a consequence, Hunt says, the validity of Catholic sacraments is thrown into doubt, since one cannot be sure which priests or bishops administering the sacraments to the Catholic faithful derive their "null" orders by succession from Formosus. Such is the ominous shadow the case of Formosus is said to cast upon the doctrine of papal infallibility, apostolic succession, and the Catholic sacraments.
To respond to the anti-infallibilist, it is important to recall what an ex cathedra declaration is and what it is not. For a papal declaration to be considered ex cathedra, and thereby infallible, the pope must intend to speak to the Church with his full authority as supreme teacher on a matter of faith and morals. Ex cathedra statements are not only rare, but in scope they exclude a great deal. Dr. Hergenroth, in his book on Vatican I, noted that "Not every papal expression, still less action, can be taken to be a definitio ex cathedra. Mere mandates of the pope for special cases, and for particular persons; judgments on individuals resting on the testimony of third persons, and in general on human evidence; declarations and answers to the inquiries of individuals; private expressions in learned works, and in confidential letters—even mere disciplinary decrees—belong not to this category." The essential question is: Do the declarations regarding Formosus’s guilt and the nullity of his ordinations meet the criteria to be considered ex cathedra?
According to historian J. N. D. Kelly, Formosus was found guilty by Stephen VI of "perjury, violating the canons prohibiting the translation of bishops, and coveting the papacy." He was not accused of professing or teaching a heretical doctrine contrary to the Catholic faith. The main charge of those brought against Formosus was the ostensible violation of the fifteenth canon of the Council of Nicaea, which forbade the translation or transfer of a bishop from one see to another, as occurred upon his election to the papacy.
The wording of the canon at the center of the dispute makes it clear that the transfer of bishops involved no irreformable doctrine of faith and morals. Rather, this custom was quite mutable and reformable. In adopting the canon, the council fathers at Nicaea noted the transfer of bishops was a hitherto accepted custom, even as they outlawed future instances. Even after the Council, dispensations from the canon were granted and recognized, proving that the canon was never considered by the Church to be an irreformable dogmatic one. Since the verdicts involved judgments related to a reformable ecclesiastical rule and not a matter of faith and morals, they cannot be considered to have been made ex cathedra.
The nullification of Formosus’s orders was the inevitable consequence of Formosus being found in violation of canon fifteen, which called for such arrangements to be "totally annulled." Whether one judged the orders conferred by Formosus to be annulled depended on whether one found him guilty of breaking this ecclesiastical canon. The question centered on a legal point rather than a dogmatic one. If Formosus broke the canon, his subsequent actions were "unlawful." Judgments on the nullity of his orders were concerned only with whether they were lawfully conferred, not whether they were actually conferred. At no time during this case did the popes define any doctrine regarding the formal requirements necessary for a sacramentally valid reception of holy orders, nor did they rule Formosus’s ordinations were sacramentally invalid as Anglican orders have been found to be.
Yet, it might be objected, the popes explicitly declared the orders conferred by Formosus to be "null." Döllinger, De Rosa, and Hunt make the mistake of presuming the precision of theological terminology has remained a constant throughout Church history. Rather, the theology of the sacraments, including holy orders, and the accompanying nomenclature have developed and been refined over the centuries. "The early Church certainly did not distinguish carefully, as later Western canonists invariably have, between the sacramental validity of holy orders received in the apostolic succession by episcopal ordination, and the regular and licit exercise of the power conveyed by the sacrament," wrote G. Fransen in The Sacrament of Holy Orders.
In the early Church, a declaration of "nullity" in many circumstances merely equates to orders we now consider to be only illicit—but still sacramentally valid. Since the canon in question was concerned with the lawful use and conferral of orders in accord with a Church custom, the early Church could consider acts and ordinations in violation of the canon to be "invalid" or "null" without denying their sacramental validity. In other words, they were "null" with respect to the law, not to the sacramental effect.
Nor does the fact Stephen VI and Sergius III demanded pro-Formosan clergy to submit to "re-ordination" prove either pope doubted the sacramental validity of Formosus’s ordinations. It needs to be remembered that Stephen VI’s and Sergius III’s aims, although scandalous, were quite practical. Owing to political intrigues of the time, they wished to purge pro-Formosan clergy and gain leverage over those admitted back into the ranks of the clergy. The two popes never delved into the deeper question of sacramental validity, nor did they need to in order to accomplish these partisan goals. By declaring Formosus’s transfer unlawful, all of Formosus’s subsequent acts could be "annulled" in accordance with the canons.
The purpose of any "re-ordination" rite would be to bestow the ecclesiastical legitimacy, not the sacramental validity, lacking in the first instance. Regarding such rites Dr. Hergenrother comments "that in the eleventh century a reconciliatory rite, already known to earlier ages, existed for the reinstallation into ecclesiastical dignities illicitly obtained, is certain."
Finally, since no ruling was issued on the sacramental validity of Formosus’s orders, there is no reason to doubt the validity of the orders conferred upon, or the sacraments administered by, those in succession from Formosus. Even if we grant that Formosus’s orders were illicit, they would still have had sacramental effect. Therefore, Hunt’s argument against apostolic succession and sacramental validity fails.
In conclusion, neither Stephen VI’s judgment against Formosus and his ordinations, John IX’s reversal of Stephen VI, nor Sergius III’s reinstatement of the original judgment, taken separately or together, contradict the doctrine of papal infallibility. These papal declarations involved reformable ecclesiastical law and not an irreformable doctrine concerning faith or morals. They cannot be considered ex cathedra pronouncements. Indeed, orthodox Catholics may consider them fallible judgments. What is clear from the historical context of this strange and confusing episode is Stephen VI and Sergius III used their authority in ecclesiastical matters to wreak revenge on past and potential enemies. The case testifies to the fact popes are prone to the same moral failings, jealousies, and abuse of power as are all men. This admission poses no difficulty to the doctrine of papal infallibility since the doctrine does not rely upon the impeccability of the popes.