No surprise here - the new Conciliar SSPX has been slowly adapting more and more to modernist Rome - and here it is quietly advertised as being in 'union with Rome': 

[Screenshot taken August 23, 2025]

https://fsspx.today/chapel/ca-arcadia/fsspx-faqs/

Quote:Pope Leo XIII

Rightly, therefore, does St. Leo the Great say: "From the whole world Peter alone is chosen to take the lead in calling all nations, to be the head of all the Apostles and of all the Fathers of the Church. So that, although in the people of God there are many priests and many pastors Peter should by right rule all of those over whom Christ Himself is the chief ruler" (Sermo iv., cap. 2).

And so St. Gregory the Great, writing to the Emperor Maurice Augustus, says: "It is evident to all who know the Gospel that the charge of the whole Church was committed to St. Peter, the Apostle and Prince of all the Apostles, by the word of the Lord... Behold! He hath received the keys of the heavenly kingdom – the power of binding and loosing is conferred upon him: the care of the whole government of the Church is confided to him" (Epist. lib. v., Epist. xx).

It was necessary that a government of this kind, since it belongs to the constitution and formation of the Church, as its principal element – that is as the principle of unity and the foundation of lasting stability – should in no wise come to an end with St. Peter, but should pass to his successors from one to another. "There remains, therefore, the ordinance of truth, and St. Peter, persevering in the strength of the rock which he had received, hath not abandoned the government of the Church which had been confided to him" (S. Leo M., sermo iii., cap. 3).

For this reason the Pontiffs who succeed Peter in the Roman Episcopate receive the supreme power in the church, jure divino. "We define," declare the Fathers of the Council of Florence, "that the Holy and Apostolic See and the Roman Pontiff hold the primacy of the Church throughout the whole world: and that the same Roman Pontiff is the successor of St. Peter, the Prince of the Apostles, and the true Vicar of Christ, the head of the whole Church, and the father and teacher of all Christians; and that full power was given to him, in Blessed Peter, by Our Lord Jesus Christ to feed, to rule, and to govern the universal Church, as is also contained in the acts of oecumenical councils and in the sacred canons" (Conc. Florentinum).

Similarly the Fourth Council of Lateran declares: "The Roman Church, as the mother and mistress of all the faithful, by the will of Christ obtains primacy of jurisdiction over all other Churches." These declarations were preceded by the consent of antiquity which ever acknowledged, without the slightest doubt or hesitation, the Bishops of Rome, and revered them, as the legitimate successors of St. Peter.

Leo XIII, Satis cognitum, §§ 12,13