1 Such, then, being the state of the case, and this number being found in all the most approved and ancient copies [of the Apocalypse], and those men who saw John face to face bearing their testimony [to it]; while reason also leads us to conclude that the number of the name of the beast, [if reckoned] according to the Greek mode of calculation by the [value of] the letters contained in it, will amount to six hundred and sixty and six; that is, the number of tens shall be equal to that of the hundreds, and the number of hundreds equal to that of the units (for that number which [expresses] the digit six being adhered to throughout, indicates the recapitulations of that apostasy, taken in its full extent, which occurred at the beginning, during the intermediate periods, and which shall take place at the end)—I do not know how it is that some have erred following the ordinary mode of speech, and have vitiated the middle number in the name, deducting the amount of fifty from it, so that instead of six decads they will have it that there is but one. [I am inclined to think that this occurred through the fault of the copyists, as is wont to happen, since numbers also are expressed by letters; so that the Greek letter which expresses the number sixty was easily expanded into the letter Iota of the Greeks.] Others then received this reading without examination; some in their simplicity, and upon their own responsibility, making use of this number expressing one decad; while some, in their inexperience, have ventured to seek out a name which should contain the erroneous and spurious number. Now, as regards those who have done this in simplicity, and without evil intent, we are at liberty to assume that pardon will be granted them by God. But as for those who, for the sake of vainglory, lay it down for certain that names containing the spurious number are to be accepted, and affirm that this name, hit upon by themselves, is that of him who is to come; such persons shall not come forth without loss, because they have led into error both themselves and those who confided in them. Now, in the first place, it is loss to wander from the truth, and to imagine that as being the case which is not; then again, as there shall be no light punishment [inflicted] upon him who either adds or subtracts anything from the Scripture, under that such a person must necessarily fall. Moreover, another danger, by no means trifling, shall overtake those who falsely presume that they know the name of Antichrist. For if these men assume one [number], when this [Antichrist] shall come having another, they will be easily led away by him, as supposing him not to be the expected one, who must be guarded against.
2. These men, therefore, ought to learn [what really is the state of the case], and go back to the true number of the name, that they be not reckoned among false prophets. But, knowing the sure number declared by Scripture, that is, six hundred sixty and six, let them await, in the first place, the division of the kingdom into ten; then, in the next place, when these kings are reigning, and beginning to set their affairs in order, and advance their kingdom, [let them learn] to acknowledge that he who shall come claiming the kingdom for himself, and shall terrify those men of whom we have been speaking, having a name containing the aforesaid number, is truly the abomination of desolation. This, too, the apostle affirms: “When they shall say, Peace and safety, then sudden destruction shall come upon them.” And Jeremiah does not merely point out his sudden coming, but he even indicates the tribe from which he shall come, where he says, “We shall hear the voice of his swift horses from Dan; the whole earth shall be moved by the voice of the neighing of his galloping horses: he shall also come and devour the earth, and the fullness thereof, the city also, and they that dwell therein.” This, too, is the reason that this tribe is not reckoned in the Apocalypse along with those which are saved.
3. It is therefore more certain, and less hazardous, to await the fulfilment of the prophecy, than to be making surmises, and casting about for any names that may present themselves, inasmuch as many names can be found possessing the number mentioned; and the same question will, after all, remain unsolved. For if there are many names found possessing this number, it will be asked which among them shall the coming man bear. It is not through a want of names containing the number of that name that I say this, but on account of the fear of God, and zeal for the truth: for the name Evanthas (ΕΥΑΝΘΑΣ) contains the required number, but I make no allegation regarding it. Then also Lateinos (ΛΑΤΕΙΝΟΣ) has the number six hundred and sixty-six; and it is a very probable [solution], this being the name of the last kingdom [of the four seen by Daniel]. For the Latins are they who at present bear rule: I will not, however, make any boast over this [coincidence]. Teitan too, (ΤΕΙΤΑΝ, the first syllable being written with the two Greek vowels ε and ι, among all the names which are found among us, is rather worthy of credit. For it has in itself the predicted number, and is composed of six letters, each syllable containing three letters; and [the word itself] is ancient, and removed from ordinary use; for among our kings we find none bearing this name Titan, nor have any of the idols which are worshipped in public among the Greeks and barbarians this appellation. Among many persons, too, this name is accounted divine, so that even the sun is termed “Titan” by those who do now possess [the rule]. This word, too, contains a certain outward appearance of vengeance, and of one inflicting merited punishment because he (Antichrist) pretends that he vindicates the oppressed. And besides this, it is an ancient name, one worthy of credit, of royal dignity, and still further, a name belonging to a tyrant. Inasmuch, then, as this name “Titan” has so much to recommend it, there is a strong degree of probability, that from among the many [names suggested], we infer, that perchance he who is to come shall be called “Titan.” We will not, however, incur the risk of pronouncing positively as to the name of Antichrist; for if it were necessary that his name should be distinctly revealed in this present time, it would have been announced by him who beheld the apocalyptic vision. For that was seen no very long time since, but almost in our day, towards the end of Domitian's reign.
4. But he indicates the number of the name now, that when this man comes we may avoid him, being aware who he is: the name, however, is suppressed, because it is not worthy of being proclaimed by the Holy Spirit. For if it had been declared by Him, he (Antichrist) might perhaps continue for a long period. But now as “he was, and is not, and shall ascend out of the abyss, and goes into perdition,” as one who has no existence; so neither has his name been declared, for the name of that which does not exist is not proclaimed. But when this Antichrist shall have devastated all things in this world, he will reign for three years and six months, and sit in the temple at Jerusalem; and then the Lord will come from heaven in the clouds, in the glory of the Father, sending this man and those who follow him into the lake of fire; but bringing in for the righteous the times of the kingdom, that is, the rest, the hallowed seventh day; and restoring to Abraham the promised inheritance, in which kingdom the Lord declared, that “many coming from the east and from the west should sit down with Abraham, Isaac, and Jacob.”
Source: Adversus haereses (New Advent)