There was no excommunication and no schism. The motu proprio referred to was in error and in conflict with the Pope's own Canon Law.
You have never answered my arguments, but instead continually disseminate falsehoods. This being the case, I am forced to once again spell out the deception and the injustice perpetrated against Archbishop Lefebvre and the SSPX. Here are the facts.
1. In all the years since Vatican II, neither Paul VI nor John Paul II had allowed a single traditionalist priest to be consecrated. Clearly Rome intended such a priesthood to pass from the scene, since only a bishop might ordain such men. Without such priests, there could be no traditional Mass. Hence the consecration of bishops was not only necessary, but crucial. All of traditional Catholicism depended on their consecration.
2. The Archbishop was 82 years old and failing in health. He was tormented by the prospect that the traditional Catholic faith was deliberately being destroyed. But despite his professed fears, Rome would not allow him the mandate he sought to consecrate traditional bishops. During this same period, JPII allowed perverts to be consecrated; he allowed outright heretics to be consecrated. But he would not allow a single traditional priest to be consecrated.
3. Meanwhile the Church was imploding. Scandals were erupting everywhere. The New Mass became the scene of more and more liturgical abuses. Statistics showed Mass attendance declining precipitously, vocations declining, whole religious orders collapsing, conversions in steep decline, seminaries shutting down at an incredible pace and those remaining compromised by corruption and heterodoxy. So the emergency was real--and the Archbishop believed it was the direct result of the radical agendas of Paul VI and JPII.
4. Negotiations ensued between the Archbishop and Rome. Rome agreed the Archbishop might have a traditionalist bishop--but would not agree to a name or a date, and would not accept a single candidate proferred by the Archbishop. Not only this, but it set up a commission to regulate traditional Catholic affairs--and this team was to be staffed by those hostile to tradition primarily.
5. The Archbishop pushed for a definite date--and got none. He finally got tired of vague promises and came to the conclusion Rome was playing a waiting game--waiting for him to die in order to take over the movement and destroy it. In his view this would have done irreparable damage to the Church. It would have meant losing the traditional Mass and the vehicle which had kept it alive for over a thousand years--the traditional priesthood--and it would have done incalculable damage to the faith.
6. Four traditionalist priests were consecrated as bishops. But the Archbishop did so by evoking a canon of Canon Law which exempted anyone from incurring a penalty if he disobeyed a superior out of fear of a state of necessity. There could have been no doubt the Archbishop sincerely believed there was such a state. He saw the situation as calamitous--and he believed modernism was out to destroy traditionalism--it had been pursuing a destructive agenda for decades since the close of the Council.
7. But there was also another canon that supported the Archbishop as well. It was a canon which stated that even if an individual WERE MISTAKEN ABOUT A STATE OF NECESSITY, as long as his belief was sincere, there could be no penalty. Now there can be no doubt whatsoever the Archbishop was sincere. He had spoken of his fears for decades. He had pleaded with Rome and railed against modernist heresies. He saw traditional Catholicism being destroyed deliberately all across the globe. There is no possibility anyone could doubt he was sincere about his fears.
8. The Pope chose to ignore all this as well as his own canons. Instead he accused the Archbishop and his followers of deliberately denying his papal authority by a sin of disobedience--a charge of outright schism. Such a charge was bizarre under the circumstances, especially in light of the fact that disobedience in Canon Law in no way implies schism, and in light of the fact that the Pope was routinely disobeyed by bishops all across the globe. Not only this, but the Pope made his charges despite the fact that the canons provided the penality of excommunication only CONDITIONALLY--i.e., only if the internal dispositions of the individuals were culpable.
9. In fact, the Canon Law decree was latae sententiae--that is to say, it was automatic and was totally dependent on the internal dispositions of the individuals involved. That is to say, only the individuals themselves could know the truth of their own circumstances. The Pope had no access to the motives of the accused--nor would he give any credence to the long history of the SSPX's defense of traditional Catholicism. The Pope, in other words, was acting as judge, juror, court, and plaintiff, all wrapped in one. This was a latae sententiae decree he was commenting on in the motu proprio--one which he could have known very little about since it depended on the internal disposition of the individuals involved, not on his papal opinion.
10. Those who defend the Pope, do so on grounds of the Archbishop's disobedience. But disobedience is not inherently evil--it is not always and everywhere wrong. It depends on the circumstance. For instance, if the Pope gave a command which would have harmed the Church, theologians insist such a command would be illegitimate. St. Robert Bellarmine put it this way:
"Just as it is licit to resist a Pontiff who aggresses the body, it is also licit to resist one who aggresses the souls or who disturbs civil order, or, above all, one who attempts to destroy the Church. I say that it is licit to resist him by not doing what he orders and preventing his will from being executed. It is not licit, however, to judge, punish, or depose him, since these are acts proper to a superior." (St. Robert Cardinal Bellarmine, doctor of the Church; De Romano Pontifice, 2,29)
11. St. Thomas Aquinas says something similar. Popes do not have a mandate to harm the Church. Nor may they impose a sentency of "schism" where it does not exist. No priest or bishop of SSPX has ever denied the Pope's legitimacy. Their sole desire was to protect Traditional Catholicism--something the Pope hismelf should be doing. Since he didn't and doesn't--they were forced to act themselves, and did so properly, according to the Pope's own Canon Law. No Motu Propio decree can change this--and the decree itself is belied by the far more authoritative canons of the Pope's own Canon Law.
12. Had the Pope wanted to prove the Archbishop culpable, he had recourse to a papal tribunal which would have had the right to call witnesses, to include evidence, and which would have allowed the accused the right to defend himself. The Pope didn't go this route--for reasons only he can know. He chose instead to accept the latae sententiae as proof of the Archbishop's excommunication and schism--when it could provide no such proof of this at all. Such penalties were dependent upon the internal dispositions of the individuals involved.
13. Another belief by those who disagree with the SSPX is that the Pope "imposed" an excommunication or declaration of schism on the SSPX. But he did no such thing. He only gave his opinion about what he believed happened automatically as a result of the consecrations. He was not himself directly involved. Besides, no Pope can impose a declaration of schism unless such a schism actually existed. He can't make something happen, if it never happened.
14. Others claim the Pope is the Supreme Legislator in the Church and may decide what he wants on the matter. But this is only partially true. He is supreme only in the legal, not the moral, sense. He can LEGALLY declare something, but he cannot effect it as a reality unless the individuals were actually guilty. This is because while the Pope is supreme on earth, he is limited by the Divine Law itself. He may not impose a sentence unjustly--which would be the case if he declared in schism individuals who remained loyal to himself but only disobeyed to protect the faith. If he does such an unjust thing, such a decaration would be a nullity.