In a couple recent debates, I quoted Pope Leo the Great as saying, “By the Holy Spirit’s inspiration the emperor needs no human instruction and is incapable of doctrinal error.” The quote is originally sourced from Henry Chadwick’s The Early Church, but it lacks a citation. By looking at details in Chadwick’s book, it appears that the quote is from Letter 165, as this letter essentially reiterates the Tome in several of its paragraphs. According to Chadwick, “the Henoticon was issued on the sole authority of the Roman Emperor” due to the ramifications of the aforesaid passage.
Did the Pope really ascribe doctrinal infallibility to a secular ruler?
A little more than a year ago, Father Maximilian Nightingale and I exchanged emails on the passage. My memory of this conversation and what actually was said do not exactly line up, which is why I should have never used Chadwick’s quote.
Father Max quickly identified the letter and found the actual passage in question:
Although I am aware that your Clemency does not lack instruction from men and that, from the abundance of the Holy Spirit, you have imbibed the purest doctrine…
He looked at the Latin and Greek versions of the letter and confirmed that the preceding rendering is more accurate than Chadwick’s. The words “incapable” and “error” are wholly lacking in the original languages. The word “need” is rendered as “lack,” but in Latin apparently both work. Nevertheless, the main thrust of Chadwick’s quote disappears when the letter is read in Latin:
Quamvis enim sciam clementiam tuam humanis institutionibus non egere, et sincerissimam de abundantia Spiritus sancti hausisse doctrinam…
Or Greek:
Ei kai ta malista gar egnokamen anthropines didaskalias ten umon emeroteta me prosdeisthai, kai ten katharotaten ek tes tou agiou pneumatos aphthonias mathesin entlekenai…
The standard rendering of the passage is high praise certainly, but it does not ascribe infallibility to the emperor.
Father Max kept digging, however, and found a couple passages in Letter 162 that may more accurately convey the idea which the Chadwick passage contains. The remainder of this article will be a discussion of these passages. In Part I, Leo wrote the following to the Emperor:
[Y]our clemency’s most excellent faith to be in all things enlarged by the gifts of heavenly grace, and I experience by increased diligence the devotion of a priestly mind in you. For in your Majesty’s communications it is beyond doubt revealed what the Holy Spirit is working through you for the good of the whole Church.
In the preceding, we see what appears to be similar praise to what we see in Letter 165. However, there are two details we should take special notice of.
First, the ascription of a special charism given to the emperor is referred to as “heavenly grace.” This grace pertains to the Emperor’s judgement as, “in your Majesty’s communications…the Holy Spirit working through you for the good of the whole Church.” The Emperor’s pronouncements (i.e. “communications”) in deciding which doctrines are to be propagated by the Church are apparently protected by God, if we are to take Leo literally. We must remind ourselves that ecumenical councils were enforced by Roman Law, so such a charism would not be useless to a Byzantine Emperor.
Second, the emperor is said to have “a priestly mind.” By this, Leo is asserting that the Emperor’s office has some sort of Apostolic (!) character. Henry Chadwick observed that Leo the Great ascribed the same thing to another emperor in Letter 134 (78).
Part II of the same letter continues in the same vein:
I know you, venerable Prince, imbued as you are with the purest light of truth, waver in no part of the Faith, but with just and perfect judgment distinguish right from wrong, and separate what is to be embraced from what is to be rejected.
The preceding passage, though perhaps worded less snazzy than Chadwick’s faulty rendering of the passage from Letter 165, is no less extreme in its claim. The Emperor’s charism is cited (“imbued…with the purest light”), his faith cannot waver, and his judgment of doctrinal matters is “perfect!” So, while the Emperor is not being ascribed infallible teaching authority (something that Leo would have ascribed to his own office), the same Emperor is being ascribed something not much less important–infallible doctrinal judgement.
Part III is the last passage pertinent to our discussion here:
I am very confident of the piety of your heart in all things, and perceive that through the Spirit of God dwelling in you, you are sufficiently instructed, nor can any error delude your faith, yet I will endeavour to follow your bidding so far as to send certain of my brothers to represent my person before you, and to set forth what the Apostolic rule of Faith is, although, as I have said, it is well known to you…
Again, Leo cites the charism of the Emperor in question (“the Spirit of God dwelling in you”) and the Emperor’s alleged infallibility in discerning doctrine (“nor can any error delude your faith.”) Yet, the passage ends with Leo tipping his hand–he’s not actually claiming the Emperor is infallible, as why would he have to send legates to “set forth…the Apostolic [See’s] rule of Faith [the Tome]” to reiterate what is already “well known” to the Emperor? Well, of course, Leo was flattering the Emperor hoping he would continue to uphold the Council of Chalcedon! It was because Leo was unsure that the Emperor would make the right decision that he wrote, so confidently, the Emperor would make the right decision.
In my honest assessment, the most outrageous form of flattery that Leo is employing is ascribing to the Emperor some sort of divine office within the Church. We see this in another letter. In Letter 156, Leo writes, “For your Majesty’s priestly and Apostolic mind ought to be still further kindled to righteous vengeance by this pestilential evil” (Par 6).
Here’s the problem: When we start ascribing an Apostolic character to the Emperor, even when it is an empty adjective (or adverb) and not an actual assertion of fact, it starts making other contemporary verbiages ring hollow. Rome, after all, is called the “Apostolic See” by Leo. Contemporary Bishops write that that “the oracles of the Apostolic Spirit [and] still recieve their [the Apostles’] interpretations” through Leo (Letter 68, Par 1).
We must ask ourselves, are such honorifics to be taken literally? That’s a topic which I will leave for another day. But in short, we do have reasons to be cautious in taking literally every glowing ancient statement we read. It is extremely important to discern the context of the statement and the actions consistent (or inconsistent) with the statement among contemporaries.
Orthodox Christian Theology 
From where do you get the idea that St Leo ascribed infallible teaching authority to his own office? St Leo didn’t call the ecumenical council, and certainly didn’t think he couldn’t err— the example of his prayer and fasting before the tomb of St Peter comes to mind, where he asks the Apostle to correct his tome (and he does). Similarly, the Council itself didn’t believe that St Leo was incapable of error, clearly, because it was only after they had judged the Tome and determined it to be consistent with St Cyril’s 12 Chapters that they exclaimed that Peter had in fact spoken through Leo.
Leo’s contemporaries did and Leo tried not even having the council, because he felt that he unilaterally settled it. But I agree with your latter comments.
The story of the first millenium of the Church relating to the papacy, in a nutshell:
1) the Popes believed that they had the care for all the Churches, that they could accept appeals, and that they were uniquely (but not solely) tasked with upholding the canons and faith of the Ecumenical Councils; they received this from ancient custom as well as from the regional Synod of Sardica, the canons of which were adopted in the East as well by the Synod in Trullo.
2) The Church told the Popes that New Rome had the exact same privileges as Old Rome (see canons 9 and 17 of ECIV, as well as the controversial 28th Canon of same). This solicitude for the other churches of God was acted upon several times: appeals to Bishop of New Rome were heard even long before Chalcedon.
3) Such care and solicitude was by no means the court of last resort. Many times Rome’s judgment was overturned completely (for example, their initial acquittal of Pelagius) by other synods, or was re-examined by general councils that did not believe themselves to be bound by Rome’s judgment.
4) Such solicitude and care for all the churches of God did not mean direct, immediate, universal authority over every Christian. Pope St. Gregory inveighed against such an idea when Constantinople’s title was changed by imperial fiat to “Ecumenical Patriarch,” because it sounded like universal direct jurisdiction. He said that such a position would mean there were no other real bishops in the world, and said that such a person would be the forerunner of the antichrist.
5) Rome’s position as first among the bishops did not mean it could not be judged, as we see from the Ec. Councils Four through Six. In ECIV, St. Leo’s Tome is scrutinized heavily by the Bishops and only accepted because it concurred in all things with St. Cyril’s 12 Chapters. St. Leo actually drafted a SECOND Tome which was more palatable to the Eastern Church. In ECV, a pope had forbidden the assembly of an Ec. Council to discuss the heretics Theodore of Mopsuestia, et al. The Emperor arrests the pope and brings him to Constantinople under house arrest, where the Council meets. The Council judges and condemns the pope’s own excusing of the heretical writings and threatens him with deposition and excommunication, at which point Vigilius changes his mind. At ECVI, one of the popes is formally anathematized: Honorius.
The problem is that the Church of Rome remembered its former status, and didn’t take well to its successive humiliations. It saw the Franks and the whole petrine office as the path to glory. It accepted heretical views on its own office, as well as on the Most Holy Trinity. To this it added the canonical crimes of additions to the Creed of Nicea and the use of azymes.
Can you send me links to each Tome?
Will try.
Papal infallibility does not apply to all of a pope’s decisions, but rather the ones made in matters of faith where the pope intends to make a point infallibly, usually after much prayer and reflection, consultation, etc, and generally to confirm or affirm definitively an already existing understanding or belief.
It is Letter 165 of Pope St. Leo I. This is a further explication of Rome’s Christology that he had promised to send the Emperor. This link is to a few book screenshots that discuss its context as a “second Tome”: https://www.dropbox.com/sh/sadx0038vj3jweq/AAAwNF03j5SFr02o2_hTkHyqa?dl=0