The interpretation timeline
2 Thessalonians 2:7 Douay-Rheims

For the mystery of iniquity already worketh; only that he who now holdeth, do hold, until he be taken out of the way.

A.D. 220 – 1849 10 witnesses

Patristic

before A.D. 750
220
A.D.
Tertullian Patristic
c. A.D. 150–220
“There is also another, even greater, obligation for us to pray for the emperors; yes, even for the continuance of the empire in general and for Roman interests. We realize that the tremendous force which is hanging over the whole world, and the very end of the world with its threat of dreadful afflictions, is arrested for a time by the continued existence of the Roman Empire. This event we have no desire to experience and, in praying that it may be deferred, we favor the continuance of Rome. APOLOGY 32.Chrysostom: One may naturally inquire what is that which restrains the man of lawlessness, and in addition, why Paul expresses it so obscurely. What then is it that holds back, that is, that hinders the revealing of, the Antichrist? Some indeed say, the grace of the Spirit, but others the Roman Empire. I agree with the latter position. Why? Because if Paul meant to say the Spirit, he would not have spoken obscurely but plainly, that even now the grace of the Spirit, that is the gifts, hold back the Antichrist. If not, he should have come by now, if his coming was to occur with the cessation of the gifts of the Spirit; for they have long since ceased. But because Paul said this of the Roman Empire, he merely touched the topic, understandably speaking covertly and darkly. For he had no need to create unnecessary enemies and useless dangers.… "For the mystery of lawlessness does already work." He speaks here of Nero, as if he were the type of the Antichrist.”
Source
303
A.D.
c. A.D. 250–303
“"And the beast which ascendeth from the abyss." After many plagues completed in the world, in the end he says that a beast ascended from the abyss. Bat that he shall ascend from the abyss is proved by many testimonies; for he says in the thirty-first chapter of Ezekiel: "Behold, Assur was a cypress in Mount Lebanon." Assur, deeply rooted, was a lofty and branching cypress-that is, a numerous people-in Mount Lebanon, in the kingdom of kingdoms, that is, of the Romans. Moreover, that he says he was beautiful in offshoots, he says he was strong in armies. The water, he says, shall nourish him, that is, the many thousands of men which were subjected to him; and the abyss increased him, that is, belched him forth. For even Isaiah speaks almost in the same words; moreover, that he was in the kingdom of the Romans, and that he was among the Caesars. The Apostle Paul also bears witness, for he says to the Thessalonians: "Let him who now restraineth restrain, until he be taken out of the way; and then shall appear that Wicked One, even he whose coining is after the working of Satan, with signs and lying wonders." And that they might know that he should come who then was the prince, he added: "He already endeavours after the secret of mischief" -that is, the mischief which he is about to do he strives to do secretly; but he is not raised up by his own power, nor by that of his father, but by command of God, of which thing Paul says in the same passage: "For this cause, because they have not received the love of God, He will send upon them a spirit of error, that they all may be persuaded of a lie, who have not been persuaded of the truth." And Isaiah saith: "While they waited for the light, darkness arose upon them." Therefore the Apocalypse sets forth that these prophets are killed by the same, and on the fourth day rise again, that none might be found equal to God.”
Source
317
A.D.
c. A.D. 240–317
“Therefore, as the end of this world approaches, the condition of human affairs must undergo a change, and through the prevalence of wickedness become worse; so that now these times of ours, in which iniquity and impiety have increased even to the highest degree, may be judged happy and almost golden in comparison of that incurable evil. For righteousness will so decrease, and impiety, avarice, desire, and lust will so greatly increase, that if there shall then happen to be any good men, they will be a prey to the wicked, and will be harassed on all sides by the unrighteous; while the wicked alone will be in opulence, but the good will be afflicted in all calumnies and in want. All justice will be confounded, and the laws will be destroyed. No one will then have anything except that which has been gained or defended by the hand: boldness and violence will possess all things. There will be no faith among men, nor peace, nor kindness, nor shame, nor truth; and thus also there will be neither security, nor government, nor any rest from evils. For all the earth will be in a state of tumult; wars will everywhere rage; all nations will be in arms, and will oppose one another; neighbouring states will carry on conflicts with each other; and first of all, Egypt will pay the penalties of her foolish superstitions, and will be covered with blood as if with a river. Then the sword will traverse the world, mowing down everything, and laying low all things as a crop. And-my mind dreads to relate it, but I will relate it, because it is about to happen-the cause of this desolation and confusion will be this; because the Roman name, by which the world is now ruled, will be taken away from the earth, and the government return to Asia; and the East will again bear rule, and the West be reduced to servitude. Nor ought it to appear wonderful to any one, if a kingdom founded with such vastness, and so long increased by so many and such men, and in short strengthened by such great resources, shall nevertheless at some time fall. There is nothing prepared by human strength which cannot equally be destroyed by human strength, since the works of mortals are mortal.”
Source
379
A.D.
Basil of Caesarea Patristic
c. A.D. 330–379
“Now, if good order with its attendant harmony is characteristic of those who look to one source of authority and are subject to one king, then universal disorder and disharmony are a sign that leadership is lacking. By the same token, if we discover in our midst such discord as I have mentioned, both with regard to one another and with respect to the Lord's commands, it would either be an indictment or our rejection of the true king. That agrees with the scriptural saying, "only that he who now holds back does so until he is taken out of the way," or of denial of him according to the psalmist, "The fool has said in his heart: There is no God."”
Source
date
unknown
c. A.D. 380
“For in the last days false prophets shall be multiplied, and such as corrupt the word; and the sheep shall be changed into wolves, and love into hatred: for through the abounding of iniquity the love of many shall wax cold. For men shall hate, and persecute, and betray one another. And then shall appear the deceiver of the world, the enemy of the truth, the prince of lies, [2 Thessalonians 2:3-12] whom the Lord Jesus "shall destroy with the spirit of His mouth, who takes away the wicked with His lips; and many shall be offended at Him. But they that endure to the end, the same shall be saved. And then shall appear the sign of the Son of man in heaven;" [Isaiah 11:4; Matthew 24:1-51] and afterwards shall be the voice of a trumpet by the archangel; and in that interval shall be the revival of those that were asleep. And then shall the Lord come, and all His saints with Him, with a great concussion above the clouds, with the angels of His power, [Matthew 16:27] in the throne of His kingdom, to condemn the devil, the deceiver of the world, and to render to every one according to his deeds. "Then shall the wicked go away into everlasting punishment, but the righteous shall go into life eternal," [Matthew 25:46] to inherit those things "which eye has not seen, nor ear heard, nor have entered into the heart of man, such things as God has prepared for them that love Him;" [1 Corinthians 2:9] and they shall rejoice in the kingdom of God, which is in Christ Jesus.”
Source
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“"And now ye know that which restraineth, to the end that he may be revealed in his own season. For the mystery of lawlessness doth already work: only there is one that restraineth now, until he be taken out of the way." One may naturally enquire, what is that which withholdeth, and after that would know, why Paul expresses it so obscurely. What then is it that withholdeth, that is, hindereth him from being revealed? Some indeed say, the grace of the Spirit, but others the Roman empire, to whom I most of all accede. Wherefore? Because if he meant to say the Spirit, he would not have spoken obscurely, but plainly, that even now the grace of the Spirit, that is the gifts, withhold him. And otherwise he ought now to have come, if he was about to come when the gifts ceased; for they have long since ceased. But because he said this of the Roman empire, he naturally glanced at it, and speaks covertly and darkly. For he did not wish to bring upon himself superfluous enmities, and useless dangers. For if he had said that after a little while the Roman empire would be dissolved, they would have warred against him. And he did not say that it will be quickly, although he is always saying it-but what? "that he may be revealed in his own season," he says, "For the mystery of lawlessness doth already work." He speaks here of Nero, as if he were the type of Antichrist. For he too wished to be thought a god. And he has well said, "the mystery"; that is, it worketh not openly, as the other, nor without shame. For if there was found a man before that time, he means, who was not much behind Antichrist in wickedness, what wonder, if there shall now be one? But he did not also wish to point him out plainly: and this not from cowardice, but instructing us not to bring upon ourselves unnecessary enmities, when there is nothing to call for it. So indeed he also says here. "Only there is one that restraineth now, until he be taken out of the way," that is, when the Roman empire is taken out of the way, then he shall come. And naturally. For as long as the fear of this empire lasts, no one will willingly exalt himself, but when that is dissolved, he will attack the anarchy, and endeavor to seize upon the government both of man and of God. For as the kingdoms before this were destroyed, for example, that of the Medes by the Babylonians, that of the Babylonians by the Persians, that of the Persians by the Macedonians, that of the Macedonians by the Romans: so will this also be by the Antichrist, and he by Christ, and it will no longer withhold. And these things Daniel delivered to us with great clearness.”
Source
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“But others think that the words, "Ye know what withholdeth," and "The mystery of iniquity worketh," refer only to the wicked and the hypocrites who are in the Church, until they reach a number so great as to furnish Antichrist with a great people, and that this is the mystery of iniquity, because it seems hidden; also that the apostle is exhorting the faithful tenaciously to hold the faith they hold when he says, "Only he who now holdeth, let him hold until he be taken out of the way," that is, until the mystery of iniquity which now is hidden departs from the Church. For they suppose that it is to this same mystery John alludes when in his epistle he says, "Little children, it is the last time: and as ye have heard that Antichrist shall come, even now are there many antichrists; whereby we know that it is the last time. They went out from us, but they were not of us; for if they had been of us, they would no doubt have continued with us." As therefore there went out from the Church many heretics, whom John calls "many antichrists," at that time prior to the end, and which John calls "the last time," so in the end they shall go out who do not belong to Christ, but to that last Antichrist, and then he shall be revealed.”
Source

Scholastic

c. 1100 – 1500
1272
A.D.
Thomas Aquinas Catholic
1225–1274
“Above, the Apostle, foretelling, narrated the coming and the guilt of the Antichrist; here he shows the cause of the delay. And first he shows that they have the cause of this knowledge; second he sets forth that cause obscurely, at the words for the mystery. He says therefore: I say that the man of sin must be revealed. And what now restrains — that is, what is the cause that delays it — you know, because I have told you, so that thus at present it is restrained, that in its own time — that is, at the fitting time — it may be revealed. Ecclesiastes 8:6: for every matter there is a time and an opportunity. And in the same place, 3:11: God has made everything good in its time, et cetera. Then, when he says for the mystery, etc., he sets forth its cause. And this text is expounded in many ways, because this word mystery can be in the nominative case, or the accusative. If in the first way, the sense is: I say that in its own time, because even now the mystery — that is, figuratively hidden — is at work in pretenders, who seem good, and yet are evil. And these perform the office of the Antichrist. 2 Timothy 3:5: having a form of godliness, but denying its power. But in the second way, the sense is: for the Devil, in whose power the Antichrist will come, already begins to work his iniquity secretly, through tyrants and seducers, because the persecutions of the Church of this time are figures of that last persecution against all the good, and are, as it were, imperfect in comparison to it. Only that he who now restrains, et cetera. This is expounded in many ways. In one way, according to the Gloss and Augustine, who say that certain persons supposed that Nero, who first persecuted the Christians, was the Antichrist, and that he had not been slain, but withdrawn, and would at some time be restored. Whence the Apostle, dispelling this, says only that he who now restrains — the Roman empire — should hold, until he be taken out of the way — that is, until he dies. But this way is not fitting, because it is many years since Nero died, namely in that year in which the Apostle. But it is better that it be referred to Nero, insofar as he is a public person of the Roman empire, until he be taken out of the way — that is, until the Roman empire be removed from this world. Isaiah 23:9: the Lord of hosts has purposed this, to bring down the pride of all glory, and unto ignominy, et cetera. Or otherwise: only that he who now restrains — that is, who now holds back the coming of the Antichrist — should hold, lest he come; as though it were necessary that still some should come to the faith, and some fall away. As if he were to say: that the departure and approach, which now holds until he come, should hold until that foul one be taken away. Or thus: only let him who now holds the faith, hold it — that is, let him be firm in it. Apocalypse 2: hold fast what you have, that no one take your crown — until he be taken out of the way — that is, until the mingled congregation of the wicked be separated, and become distinct, which will be in the persecution of the Antichrist. Or only, etc. — that is, that the mystery of iniquity, that is, the mystical iniquity, which restrains, may restrain until it be taken out of the midst — that is, until the iniquity be brought into the open, and become, as it were, something existing openly out of the midst. For many now sin in secret, but nevertheless at some time it will be done openly; for God bears with sinners as long as they are hidden, until they sin publicly, and then he will not bear with them, as is clear concerning the Sodomites in Genesis 19:24. But nevertheless Augustine confesses that he does not know what the Apostle is saying to them, who already knew. Whence he says, what now restrains, you know. And besides, this was not very necessary to know. Then, when he says and then, etc., the coming of the wicked one is set forth, and his punishment. First the manifestation; second his punishment. As to the first, he says that wicked one — in the singular — shall be revealed, because his guilt will be manifest, whom the Lord Jesus will slay with the spirit of his mouth. Isaiah 11: the zeal of the Lord of hosts shall do this — that is, the zeal of justice, which is love. For the spirit of Christ is the love of Christ, and this zeal belongs to the Holy Spirit, which he has toward the Church. Or by the spirit of his mouth, that is, by his command; because Michael is to slay him on the Mount of Olives, from where Christ ascended; thus also Julian was extinguished by the divine hand. And this is the present punishment, although he will also be punished eternally in the future, because he will destroy by the brightness, etc. — that is, by his coming, illuminating all things. 1 Corinthians 4:5: he will bring to light the hidden things of darkness, et cetera. And he will destroy, I say, eternally, namely by damnation. Psalm 27:5: he shall destroy them, et cetera. And he says, by the brightness, because he himself was seen to darken the Church, and darkness is driven away by brightness, because whatever the Antichrist shall show, it shall be shown to have been a lie. Then, when he says whose coming is, he foretells the power of the Antichrist. And concerning this he does two things: first he sets forth his power to seduce; second, the cause of this from the justice of the Lord, at the words because the love. Again the first is divided into three, because first he sets forth the author of this power; second, the manner of seducing; third he shows those who are to be seduced. The author of this power is the Devil, and therefore Christ will destroy him. 1 John 3:8: for this the Son of God appeared, that he might dissolve the works of the Devil. And therefore he says that the coming of the Antichrist will be according to the working of Satan — that is, from his instigation. Apocalypse 20:7: Satan will be released from his prison, and will go out, and will seduce the nations, et cetera. For something works according to the working of Satan, as in the possessed, in whom he not only instigates the will, but also impedes the use of reason; which, however, is not imputed to his fault, because he does not have the use of free will. But the Antichrist is not so; rather he will have the use of free will, in which the Devil is suggesting, as is said of Judas, John chapter 3: Satan entered into him — namely, by instigating. But he will deceive in this manner: first through secular power; second through the power of miracles. As to the first, he says in all power — namely, secular power. Daniel 11:43: he shall have dominion over the treasures of gold and silver, and over all the precious things of Egypt. Or power, namely feigned. But as to the second he says in signs, et cetera. Signs are certain wonders, even small ones. But prodigies are great, which show something prodigious, as it were far from the finger. Revelation 13:13: he did great signs, so that he even made fire come down from heaven, et cetera. Matthew 24:24: they shall give great signs and wonders, so that, if it were possible, even the elect would be led into error. And he says lying. A miracle is called lying, either because it lacks the true nature of the deed, or the true nature of a miracle, or the due end of a miracle. The first happens in illusions, when through demons the sight is deceived, so that something appears other than it is: as Simon Magus made a ram be beheaded, and afterward it was shown alive; and a man was beheaded, and afterward the man, who was believed to have been beheaded, was shown alive, and was believed to have been raised. And this men do by changing phantasms and deceiving. In the second way, those things are called miracles improperly which are full of wonder, when the effect is seen and the cause is unknown. Therefore, those things which have a cause hidden to someone, and not absolutely, are indeed called wonders, and not miracles absolutely. But those which have a cause absolutely hidden are properly miracles, whose cause is God himself, the glorious one, because they transcend the whole order of created nature. But sometimes certain wonders happen, not beyond the order of nature, but having hidden causes; and these the demons do much more, who know the powers of nature, and who have determined efficacies for special effects, and these the Antichrist will do; but not those which have the true nature of a miracle, because they cannot do those things which are above nature. In the third way, they are called miracles insofar as they are ordered to bearing witness to the truth of the faith, to bringing back the faithful to God. Mark, last chapter: the Lord working with them, and confirming the word with signs that followed. But if the glory of miracles is present to someone, and he does not use them for this end, the miracles are indeed true as to the nature of the deed done, and as to the nature of a miracle, but they are false as to the due end, and the intention of God. But nevertheless this will not be in the Antichrist, because no one against the faith does true miracles, because God is not a witness of falsehood. Whence someone preaching false doctrine cannot do miracles, although someone having an evil life could. Then he shows those who are to be seduced, when he says to those who perish — that is, among those foreknown unto perdition. John 17:12: none of them perished, but the son of perdition. And this for this reason, because John 10:27: my sheep hear my voice.”

Post-Reformation

c. 1650 – 1900
1832
A.D.
Adam Clarke Methodist
1762–1832
“For the mystery of iniquity doth already work - There is a system of corrupt doctrine, which will lead to the general apostasy, already in existence, but it is a mystery; it is as yet hidden; it dare not show itself, because of that which hindereth or withholdeth. But when that which now restraineth shall be taken out of the way, then shall that wicked one be revealed-it will then be manifest who he is, and what he is. See the observations at the end of this chapter (note).”
Source
1849
A.D.
1774–1849
“The mystery of iniquity already worketh, [8] or is now wrought, by the precursors of antichrist; i.e. by infidels and heretics. For, as St. John says, there are many antichrists, precursors to the great antichrist, and enemies of Christ. (1 John chap. ii.) (Witham) — That he who now holdeth, do hold. That is, let each one remain in the faith which he has received of us, and let him not permit himself to be deceived by any discourse, as coming from us. Or rather, let those who shall then be in the world keep their faith, remaining firm in their belief and attachment to the Church of Christ, until antichrist, that man of iniquity, shall be taken away. (Calmet) — According to others, it is an admonition to the faithful not to be beguiled during this day of trial by such, as under the garb of religion, and with an ostentatious parade of zeal for the holy Scriptures, seek to deceive them. When the mystery of sin shall be revealed, then shall we plainly discover that apostacy from the Catholic Church is the obvious and certain road to a dereliction of all religious principle; yes, to antichristianism and to atheism. (Haydock)”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.