The reason why the Roman Church, which really only comes to prominence in the Commodian era, translated μυστήριον with sacramentum was because it was already reshaping the Alexandrian mystery tradition away from its 'heretical' roots. This is made plainly evident in the Liber Pontificalis's description of the events of Pope Victor (c. 185 CE) where it says:
He appointed that the holy feast of Easter should be observed upon the Lord's day ... He instituted a clergy in attendance ... He also ordained that, at a time of necessity, any gentile who came to be baptized, wherever it might be, whether in a river or in the sea or in a spring or in a marsh if only he pronounced the Christian confession of faith, should be thereafter a Christian in full standing.
He held two ordinations in the month of December, four priests, seven deacons, twelve bishops in diverse places. He also summoned a council and an inquiry among the clergy concerning the cycle of Easter and the Lord's day for Easter, and he gathered together the priests and the bishops. Then Theophilus, bishop of Alexandria, was questioned [Lat. interrogationem] and in the assembly it was decided that the Lord's day between the fourteenth day of the moon in the first month and the twenty first day of the moon should be kept as the holy feast of Easter. [p. 19]
When one reads the section on Victor IN THE CONTEXT of the whole Liber Pontificalis it is quite apparent that it is under his rule that the Church of Rome first rose to prominence. We see him actively expanding the number of priests, deacons and bishops.
Then we should also notice that the definition of baptism here is completely transformed from its original understanding as μυστήριον. Before I go any further I should note that traditional scholarship goes so far as to argue AGAINST the idea that baptism was originally identified as the μυστήριον of the Church. As Osborne writes:
The New Testament does not speak of baptism as a sacrament; indeed the early Christians would not understand us with our theology of sacrament. Only gradually did the Greek terms, mysterion and symbolon and the Latin term sacramentum come to refer to liturgical actions. Actually the first clear reference is found in Athanasius (295 - 373 CE) but beginnings of this classification can already be found in Clement of Alexandria, Origen, Tertullian and Hippolytus. It is in this linguistic development that some influence from the Hellenistic mystery cults can be seen. The initiation into these mystery cults, called a muesis, gave rise to the Christian naming of baptism as mysterion. Let us be clear: Christian baptism as an act, and a liturgical act at that, already was practiced; the naming of this act as mysterion came second. [The Christian Sacrament p. 57]
Yet is Osborne really correct here? He certainly doesn't think that Christianity STARTED in Alexandria. If indeed these earliest representatives of Alexandrian theology can be argued to have understood baptism as mysterion we would be able to argue that only OUTSIDE of Alexandria - i.e. in Rome - was there a conscious effort to DENY the kind of 'mystery' baptism developed in Egypt.
Of course there is a very significant problem here which scholars never take into account when they boldly pronounce - like Osborne - that Clement avoided NAMING baptism as mysterion. Would one expect those who engaged in pagan mysteries to openly acknowledge what went on behind close doors of their religion?
Oh, but Clement was writing to fellow 'brothers' in the greater Church. As such he would have no reason to deny the μυστήριον of the Alexandrian Church, right?
Well, all of that might have been true before the discovery of the Mar Saba letter.
Clearly this text makes absolutely certain that the details of the liturgy of the Alexandrian Church were in some sense kept secret from other Christians outside of Egypt. It is clear from his discussion with Theodore that the longer mystikon euangelion at the heart of the Alexandrian liturgy is unknown to those outside of Egypt.
As Brown notes "mystikon is the adjective corresponding to the noun mysterion, the basis for the English word “mystery.” The meaning of the adjective, therefore, should be sought with regard to how Clement used the noun mysterion and other derivatives of this word." [Mark's Other Gospel p. 152] Yet we must qualify Brown's statement here.
Should we expect that Clement would ever make explicit the μυστήριον of the Alexandrian Church to outsiders? Of course not. So unfortunately we are now in a position of having to admit that we will likely never get an explicit 'confession' of what μυστήριον meant to Clement especially as even the Letter to Theodore is written to an outsider of the Alexandrian tradition.
To this end Brown's conclusion that "[t]he lack of a cultic or sacramental connection in Clement’s use of mysterion (in his other writings) was documented in an article by H.G. Marsh in 1936 and does not need to be demonstrated again here" [ibid] can be attributed to these men not thinking through the implausibility of their own assumptions. To put matters in every day terms, that a man publicly confesses his fidelity to his wife doesn't prove anything.
Indeed let's spend some time seeing if Brown basically walks over the clues which can be used to demonstrate that baptism was SECRETLY understood to be the μυστήριον of the Alexandrian community. Here is what he writes in full:
[f]or Clement, the mysteries were divine truths concealed beneath the literal level of the scriptures (e.g., Strom. I.5.32.3). A contrived exposition of the two occurrences of mysterion in Col 1:25–27 provided Clement with the basis for his claim that the divine mysteries (he turned the word into a plural) were of two types: the gnostic tradition, which is reserved for the few, and the once hidden message of salvation, which is now openly proclaimed to the Gentiles (V.10.60.1–61.1).17 On occasion Clement followed Philo and Justin in using mysterion as a synonym for the terms symbol and parable (I.12.55.1; V.12.80.7).18 But in Clement’s writings, mysterion does not usually refer to the form or manner by which scripture reveals its truths; that is the function of mystikon (the adjective) and mystikos (the adverb). Clement normally used mysterion to designate the deeper truths themselves. Because Clement divided the mysteries into two kinds, he was able to “disclose” the exoteric Christian truths through allegorical exposition, the same method by which the gnostic mysteries were imparted. But he still preserved the distinction between what belongs to the many and what only to a few. Clement sometimes described the different levels of mysteries using mystery-religion language of a gradation of mysteries, including a distinction between “the small and the great mysteries” (Strom. IV.1.3.1; V.11.71.1; cf. I.1.15.3).20 An Alexandrian believer might hear the longer text when being initiated into the latter (Letter to Theodore II.2). [p. 159]
Now let's stop right there because Brown will immediately go from here to argue that Clement understood the term μυστήριον allegorically as it were in the manner of the philosophers like Plato. In other words, that there was no connection to any 'sacraments' per se.
Brown can't see the ground that he is standing on because he hasn't yet made the connection between Clement and the Marcosians (i.e. the heretical followers of Mark identified in the writings of Irenaeus and Hippolytus) which I have written about here at length AND in turn this community's identification of TWO baptisms in Christianity.
The question now is whether Clement's identification of two mysteries - one identified as 'small' and the other 'great' - are connected with his fellow Marcosians distinction between two kinds of baptism - i.e. the familiar water immersion which John gave to Jesus in the Jordan (which is the 'animal' form of the ritual) and some redemptive act connected with two separate figures named 'Jesus' and 'Christ' in the gospel narrative just before Salome's request on behalf of her sons James and John (Mark 10:35 - 45). In other words, the very place where LGM 1 appears in the Alexandrian gospel of Mark.
Just look at the way that St. Mark the author is identified as the mystagogue of the Alexandrian tradition through his composition of the mystikon euangelion which - as Clement notes forms the basis to the mysterion of Alexandria. Irenaeus almost begins his exposition of the Marcosian system by imitating their use of this kind of language.
He starts by saying "I shall endeavour to state the remainder of their mystical system (tes mystagogias auton), which runs out to great length, in brief compass, and to bring to the light what has for a long time been concealed" [AH i.13.6] and then referring to their use of a "hidden" gospel [AH i.20.1] he adds that "these persons endeavour to set forth things in a more mystical (mustikoteron) style." [AH i.14.1]
By the time Irenaeus's gets around to describing the twofold μυστήριον of 'those of Mark' it is IMPOSSIBLE not to understand that he means the Markan See of Alexandria as described in To Theodore for he notes:
Thus there are as many schemes of redemption as there are teachers of these mystical opinions (tes gnomes mystagogoi, tosautai apolutroseis) . And when we come to refute them, we shall show in its fitting-place, that this class of men have been instigated by Satan to a denial of that baptism which is regeneration to God, and thus to a renunciation of the whole faith. They maintain that those who have attained to perfect knowledge must of necessity be regenerated into that power which is above all. For it is otherwise impossible to find admittance within the Pleroma, since this [regeneration] it is which leads them down into the depths of Bythus. For the baptism instituted by the visible Jesus was for the remission of sins, but the redemption brought in by that Christ who descended upon Him, was for perfection; and they allege that the former is animal, but the latter spiritual. And the baptism of John was proclaimed with a view to repentance, but the redemption by Jesus was brought in for the sake of perfection. And to this He refers when He says, "And I have another baptism to be baptized with, and I hasten eagerly towards it." Moreover, they affirm that the Lord added this redemption to the sons of Zebedee, when their mother asked that they might sit, the one on His right hand, and the other on His left, in His kingdom, saying, "Can ye be baptized with the baptism which I shall be baptized with?" Paul, too, they declare, has often set forth, in express terms, the redemption which is in Christ Jesus; and this was the same which is handed down by them in so varied and discordant forms.
For some of them prepare a nuptial couch, and perform a sort of mystic rite (mustagogian epitelousi) pronouncing certain expressions with those who are being initiated, and affirm that it is a spiritual marriage which is celebrated by them, after the likeness of the conjunctions above. Others, again, lead them to a place where water is, and baptize them, with the utterance of these words, "Into the name of the unknown Father of the universe--into truth, the mother of all things--into Him who descended on Jesus--into union, and redemption, and communion with the powers." [AH i.21.1 - 3]
I think when the dust settles on the 'debate' about the authenticity of To Theodore over the last generation almost everyone will come to see that I have discovered the CONTEXT of the letter. Clement was a crypto-Marcosian. Irenaeus knows and understands that there is another gospel associated with 'Mark' connected to another baptism more perfect than the familiar portrait of John baptizing Jesus in the Jordan.
All people have to do is remember that Clement COULDN'T reference the idea that baptism was the mysterion of his Alexandrian community because he was living in the same age that the bishop of Alexandria was brought to Rome to be interrogated about that same mystical system.
Nevertheless he does manage to convey the idea that there is another baptism beside the familiar 'animal' baptism of Jesus by John in the Jordan by speaking of TWO MYSTERIES in the Church of Alexandria in cryptic references such as:
[the Lord] allowed us to communicate of those divine mysteries, and of that holy light, to those who are able to receive them. He did not certainly disclose to the many what did not belong to the many; but to the few to whom He knew that they belonged, who were capable of receiving and being moulded according to them. But secret things are entrusted to speech, not to writing, as is the case with God. [Strom i.1]
And to him who is able secretly to observe what is delivered to him. that which is veiled shall be disclosed as truth; and what is hidden to the many, shall appear manifest to the few. For why do not all know the truth? why is not righteousness loved, if righteousness belongs to all? But the mysteries are delivered mystically, that what is spoken may be in the mouth of the speaker; rather not in his voice, but in his understanding. [ibid]
So that we may have our ears ready for the reception of the tradition of true knowledge; the soil being previously cleared of the thorns and of every weed by the husbandman, in order to the planting of the vine. For there is a contest, and the prelude to the contest; and them are some mysteries before other mysteries. [ibid]
But since this tradition is not published alone for him who perceives the magnificence of the word; it is requisite, therefore, to hide in a mystery the wisdom spoken, which the Son of God taught. [ibid i.12]
I know Brown and others have combed through WHAT IS WRITTEN about Clement's writings BEFORE the discovery of To Theodore in order to argue that mysterion doesn't mean baptism but that's a little like going back to 1976 and arguing from the fact that Elton John was married he wasn't gay.
The discovery of To Theodore changes everything not only about Clement but our understanding of the history of the Church. Clement was a crypto-Marcosian. He lived in an age when the Roman Church was interrogating the leadership of his community. Irenaeus was actively demonizing the tradition of Mark in order to justify the persecution of those attached to the Alexandrian tradition in places outside of Egypt.
You can't begin with the assumption that Clement was being 'open' about his beliefs when we know these things were going on.
So it is that if people were to spend time ACTUALLY comparing what is written about the Marcosians in Irenaeus to the beliefs of Clement both in his 'accepted' writings (i.e. those prior to Morton Smith's discovery) and to Theodore they would IMMEDIATELY SEE the connection. Take for example what Irenaeus says about the Marcosians that "in a word, whatever they find in the Scriptures capable of being referred to the number eight, they declare to fulfil the mystery of the Ogdoad" [AH i.18.3] is echoed by Clement's reference to "the gnostic mystery of the numbers seven and eight" [Strom. iv.17] during his exposition of 'the apostle Clement' (i.e. 1 Clement).
I have identified fifty other proofs that Clement was a Marcosian here. It is time to see however that the IMPLICATION of the identification of that affiliation is that not only did Clement SECRETLY identify baptism with the mysterion of the Alexandrian community, he actually posited TWO baptisms which corresponded to 'greater and lesser' mysteries in the exact same way as there was a lesser gospel 'for the increase of faith' [Theod i.17,18] and a "more spiritual gospel for those being perfected" [ibid i.21,22].
Indeed for those who are capable of such understanding, I have noted many times before that the REASON why the greater μυστήριον associated with LGM 1 is connected with the mystical Ogdoad (counting after the Jewish manner there is the explicit mention to seven days - i.e. the end of the day before the sun went down when the youth is resurrected from the tomb [Theod iii.1 - 6] plus 'six days' [ibid iii.7] and then the eighth day when he was taught the μυστήριον τῆς βασιλείας τοῦ θεοῦ) is owing to the underlying connection with the 'redemption' traditionally associated with the ancient Israelites crossing the Sea as the seventh day 'went out' into the eighth. Hence the parallel reference in Secret Mark.
dating back to conversations with his grandfather, Gaston Frank. "He said we represent one of the last descendants of the Frankist Jewish faith in the world," he muses. "I grew up thinking that our family was something like the Last of the Mohicans."