Text edited by Rev. Alexander Roberts and James Donaldson and first published by T&T Clark in Edinburgh in 1867. Additional introductionary material and notes provided for the American edition by A. Cleveland Coxe, 1886.
The Epistles of Pope Callistus. 
The First Epistle. To Bishop Benedictus.
On the Fasts of the Four Seasons, and that no one should take up an accusation against a doctor (teacher).
Callistus, archbishop of the Church Catholic in the city of Rome, to Benedictus, our brother and bishop, greeting in the Lord.
By the love of the brotherhood we are bound, and by our apostolic rule we are constrained, to give answer to the inquiries of the brethren, according to what the Lord has given us, and to furnish them with the authority of the seal of the apostles.
Footnotes Callistus succeeded Zephyrinus in the bishopric of Rome, and discharged the duties of that office for five years. This is all the information which Eusebius (in his Chronicon and Hist. Eccl., vi. 21) gives us in regard to Callistus. Later writers make many other statements. [See note, p. 618.] The letters attributed to him form part of the False Decretals of the pseudo-Isidorus, mentioned in the notice of Zephyrinus.  Mansi, Concil., i. 737.
|BELIEVE Religious Information Source - By Alphabet Our List of 2,300 Religious Subjects|
Fasting, which ye have learned to hold three times in the year among us, we decree now to take place, as more suitable, in four seasons; so that even as the year revolves through four seasons, we too may keep a solemn fast quarterly in the four seasons of the year. And as we are replenished with corn, and wine, and oil for the nourishment of our bodies, so let us be replenished with fasting for the nourishment of our souls, in accordance with the word of the prophet Zechariah, who says, "The word of the Lord came to me, saying, Thus saith the Lord of hosts, As I thought to punish you, when your fathers provoked me to wrath, and I repented not; so again have I thought in these days to do well unto Jerusalem, and to the house of Judah: fear ye not. These are the things that ye shall do: Speak ye every man the truth to his neighbour; judge the truth and the judgment of peace in your gates; and let none of you imagine evil in your hearts against his neighbour, and love no false oath: for all these are things that I hate, saith the Lord of hosts. And the word of the Lord of hosts came unto me, saying, Thus saith the Lord of hosts, The fast of the fourth month, and the fast of the fifth, and the fast of the seventh, and the fast of the tenth, shall be to the house of the Lord joy and gladness, and cheerful feasts; only love the truth and peace, saith the Lord of hosts." In this, then, we ought to be all of one mind, so that, according to apostolic teaching, we may all say the same thing, and that there be no divisions among us. Let us then be perfect in the same mind, and in the same judgment;  in ready zeal for which work we congratulate ourselves on having your affection as our partner. For it is not meet for the members to be at variance with the head; but, according to the testimony of sacred Scripture,  all the members should follow the head. It is matter of doubt, moreover, to no one, that the church of the apostles is the mother of all the churches, from whose ordinances it is not right that you should deviate to any extent. And as the Son of God came to do the Father's will, so shall ye fulfil the will of your mother, which is the Church, the head of which, as has been stated already, is the church of Rome. Wherefore, whatsoever may be done against the discipline of this church, without the decision of justice, cannot on any account be permitted to be held valid.
Moreover, let no one take up an accusation against a doctor (teacher), because it is not right for sons to find fault with fathers, nor for slaves to wound their masters. Now, all those whom they instruct are sons of doctors; and as sons ought to love their fathers after the flesh, so ought they to love their spiritual fathers. For he does not live rightly who does not believe rightly, or who reprehends fathers, or calumniates them. Doctors therefore, who are also called fathers, are rather to be borne with than reprehended, unless they err from the true faith. Let no one, consequently, accuse a doctor by writing (per scripta); neither let him answer to any accuser, unless he be one who is trustworthy and recognised by law, and who leads also a life and conversation free from reproach. For it is a thing unworthy that a doctor should reply to a foolish and ignorant person, and one who leads a reprehensible life, according to the man's folly; as Scripture says, Answer not a fool according to his folly. He does not live rightly who does not believe rightly. He means nothing evil who is faithful. If anyone is faithful (a believer), let him see to it that he make no false allegations, nor lay a snare for any man. The faithful man acts always in faith; and the unfaithful man plots cunningly, and strives to work the ruin of those who are faithful, and who live in piety and righteousness, because like seeks like. The unfaithful man is one dead in the living body. And on the other hand, the discourse of the man of faith guards the life of his hearers. For as the Catholic doctor, and especially the priest of the Lord, ought to be involved in no error, so ought he to be wronged by no machination or passion. Holy Scripture indeed says, Go not after thy lusts, but refrain thyself from thine appetites;  and we must resist many allurements of this world, and many vanities, in order that the integrity of a true continence may be obtained, whereof the first blemish is pride, the beginning of transgression and the origin of sin; for the mind with lustful will knows neither to abstain nor to give itself to piety. No good man has an enemy except in the wicked, who are permitted to be such only in order that the good man may be corrected or exercised through their means. Whatever, therefore, is faultless is defended by the Church Catholic. Neither for prince, nor for any one who observes piety, is it lawful to venture anything contrary to the divine injunctions. Consequently an unjust judgment, or an unjust decision (diffinitio), instituted or enforced by judges under the fear or by the command of a prince, or any bishop or person of influence, cannot be valid. The religious man ought not to hold it enough merely to refrain from entering into the enmities of others, or increasing them by evil speech, unless he also make it his study to extinguish them by good speech. Better is a humble confession in evil deeds, than a proud boasting in good deeds. Moreover, all who live the blessed life, choose rather to run that course in the proper estate of peace and righteousness, than to involve themselves in the avenging pains of our sins. For I am mindful that I preside over the Church under the name of him whose confession was honoured by our Lord Jesus Christ, and whose faith ever destroys all errors. And I understand that I am not at liberty to act otherwise than to expend all my efforts on that cause in which the well-being of the universal Church is at stake (infestatur). I hope, too, that the mercy of God will so favour us, that, with the help of His clemency, every deadly disease may be removed, God Himself expelling it, and that whatever may be done wholesomely, under His inspiration and help, may be accomplished to the praise of thy faith and devotion. For all things cannot otherwise be safe, unless, as far as pertains to the service of the divine office, sacerdotal authority upholds them. Given on the 21st day of November in the consulship of the most illustrious Antoninus and Alexander. 
(Of conspiracies and other illicit pursuits, that they be not engaged in, and of the restoration of the lapsed after penitence.)
Callistus to our most dearly beloved brethren, all the bishops settled throughout Gaul.
By the report of very many, we learn that your love, by the zeal of the Holy Spirit, holds and guides the helm of the Church so firmly in the face of all assaults, that by God's will it is conscious neither of shipwreck nor of the losses of shipwreck. Rejoicing, therefore, in such testimonies, we beg you not to permit anything to be done in those parts contrary to the apostolic statutes; but, supported by our authority, do ye check what is injurious, and prohibit what is unlawful.
Now we have heard that the crime of conspiracies prevails in your parts, and it has been shown us that the people are conspiring against their bishops; of which crime the craft is hateful, not only among Christians, but even among the heathen, and it is forbidden by foreign laws. And therefore the laws not only of the Church, but of the world, condemn those who are guilty of this crime; and not only those indeed who actually conspire, but those also who take part with such. Our predecessors, moreover, together with a very numerous body of bishops, ordained that any guilty of this offence among those who are set in the honour of the priesthood, and who belong to the clergy, should be deprived of the honour which they enjoy; and they ordered that others should be cut off from communion, and expelled from the Church; and they decreed, at the same time, that all men of both orders should be infamous (infames); and that, too, not only for those who did the deed, but for those also who took part with such. For it is but equitable that those who despise the divine mandates, and prove themselves disobedient to the ordinances of the fathers, should be chastised with severer penalties, in order that others may fear to do such things, and that all may rejoice in brotherly concord, and all take to themselves the example of severity and goodness. For if (which may God forbid) we neglect the care of the Church, and are regardless of its strength, our slothfulness will destroy discipline, and injury will be done assuredly to the souls of the faithful. Such persons, moreover, are not to be admitted to accuse any one: neither can their voice, nor that of those who are under the ban, injure or criminate any man.
Those, too, who are excommunicated by the priests, let no one receive previous to the just examination of both sides; nor let him have any intercourse with such in speech, or in eating or drinking, or in the salutation with the kiss, nor let him greet such; because, whosoever wittingly holds intercourse with the excommunicated in these or other prohibited matters, will subject himself, according to the ordinance of the apostles,  to like excommunication. From these, therefore, let clergy and laity keep themselves if they would not have the same penalty to endure. Also do not join the unbelievers, neither have any fellowship with them. They who do such things, indeed, are judged not as believers, but as unbelievers. Whence the apostle says: "What part hath he that believeth with an infidel? or what fellowship hath righteousness with unrighteousness?" 
Let no one, again, trespass upon the boundaries of another, nor presume to judge or excommunicate one belonging to another's parish; because such judgment or ordination, or excommunication or condemnation, shall neither be ratified nor have any virtue; since no one shall be bound by the decision of another judge than his own, neither shall he be condemned by such. Whence also the Lord speaks to this effect: "Pass not the ancient landmarks which thy fathers have set." Moreover, let no primate or metropolitan invade the church or parish of a diocesan (dioecesani), or presume to excommunicate or judge any one belonging to his parish, or do anything without his counsel or judgment; but let him observe this law, which has been laid down by the apostles  and fathers, and our predecessors, and has been ratified by us: to wit, that if any metropolitan bishop, except in that which pertains to his own proper parish alone, shall attempt to do anything without the counsel and good-will of all the comprovincial bishops, he will do it at the risk of his position, and what he does in this manner shall be held null and void; but whatever it may be necessary to do or to arrange with regard to the cases of the body of provincial bishops, and the necessities of their churches and clergy and laity, this should be done by consent of all the pontiffs of the same province, and that too without any pride of lordship, but with the most humble and harmonious action, even as the Lord says: "I came not to be ministered unto, but to minister." And in another passage He says: "And whosoever of you is the greater, shall be your servant,"  and so forth. And in like manner the bishops of the same province themselves should do all things in counsel with him, except so much as pertains to their own proper parishes, in accordance with the statutes of the holy fathers (who, although they have preceded us by a certain interval of time, have yet drawn the light of truth and faith from one and the same fountain of purity, and have sought the prosperity of the Church of God and the common advantage of all Christians by the same enlightening and guiding Spirit), that with one mind, and one mouth, and one accord, the Holy Trinity may be glorified for ever. No primate, no metropolitan, nor any of the other bishops, is at liberty to enter the seat of another, or to occupy a possession which does not pertain to him, and which forms part of the parish of another bishop, at the direction of any one, unless he is invited by him to whose jurisdiction it is acknowledged to belong; nor can he set about any arrangement or ordinance, or judgment there, if he wishes to keep the honour of his station. But if he presume to do otherwise, he shall be condemned; and not only he, but those who co-operate and agree with him: for just as the power of making appointments (ordinatio) is interdicted in such circumstances, so also is the power of judging or of disposing of other matters. For if a man has no power to appoint, how shall he judge? Without doubt, he shall in no wise judge or have power to judge: for just as another man's wife cannot intermarry with anyone (adulterari), nor be judged or disposed of by any one but by her own husband so long as he liveth; so neither can it in anywise be allowed that the wife of a bishop, by whom undoubtedly is meant his church or parish, should be judged or disposed of by another without his (the bishop's) judgment and good-will so long as he liveth, or enjoy another's embrace, that is, his ordaining. Wherefore the apostle says: "The wife is bound by the law so long as her husband liveth; but if he be dead, she is loosed from the law of her husband." In like manner also, the spouse of a bishop (for the church is called his spouse and wife) is bound to him while he liveth; but when he is dead she is loosed, and may be wedded to whomsoever she will, only in the Lord, that is, according to order. For if, while he is alive, she marry another, she shall be judged to be an adulteress. And in the same manner, he too, if he marry another of his own will, shall be held to be an adulterer, and shall be deprived of the privilege of communion. If, however, he is persecuted in his own church, he must flee to another, and attach himself to it, as the Lord says: "If they persecute you in one city, flee ye into another." If, however, the change be made for the sake of the good of the church, he may not do this of himself, but only on the invitation of the brethren, and with the sanction of this holy seat, and not for ambition's sake, but for the public good.
Moreover, marriages among blood-relations are forbidden, since all laws, both sacred and secular, forbid such. Wherefore the divine laws not only expel, but even anathematize, those who do so, and those who spring from them. Secular laws, again, call such persons infamous, and interdict them from inheriting. And we too, following our fathers, and keeping close by their footsteps, brand such with infamy, and hold them to be infamous, because they are sprinkled with the stains of infamy. Neither ought we to admit those men or their accusations, that secular laws reject. (For who doubts that human laws, when they are not inconsistent with reason and honour, are to be embraced, especially when they either further the public good or defend the authority of the ecclesiastical office, and uphold it as a help?) And we call those blood-relations whom divine laws, and those of the emperors, both Roman and Greek, name blood-relations, and whom they admit to the right of inheriting, and cannot exclude from that. Marriages, then, between such are neither lawful nor capable of holding good, but are to be rejected. (And if any such are attempted in rash daring, they come to be rescinded by apostolic authority.)
Whosoever, therefore, has not been lawfully married, or has been united without the dotal title (dotali titulo) and the blessing of a priest, cannot by any means bring a charge against priests, or those who are lawfully married, or bear witness against them, since every one who is polluted with the stain of incest is infamous, and is not allowed to accuse the above-named. And consequently not only they, but all those too who agree with them, are to be rejected, and are rendered infamous. We hold that the same should also be the case with robbers, or with those who assault the elderly. The laws of the world, indeed, put such persons to death; but we, with whom mercy has the first place, receive them under the mark of infamy to repentance. That infamy also with which they are stained, we are not able to remove; but our desire is to heal their souls by public penitence, and by satisfaction made to the Church: for public sins are not to be purged by secret correction. Those, again, who are suspected in the matter of the right faith, should by no means be admitted to prefer charges against priests, and against those of whose faith there is no doubt; and such persons should be held of doubtful authority in matters of human testimony. Their voice, consequently, should be reckoned invalid whose faith is doubted; and no credit should be given to those who are ignorant of the right faith. Accordingly, in judgment, inquiry should be made as to the conversation and faith of the person who accuses, and of him who is accused; since those who are not of correct conversation and faith, and whose life is open to impeachment, are not allowed to accuse their elders, neither can such permission be given to those whose faith and life and liberty are unknown. Nor should vile persons be admitted to accuse them. But a clear examination is to be made as to what kind of persons the accusers are (rimandæ sunt enucleatim personæ accusatorum); for they are not to be admitted readily without writing, and are never to be admitted as accusers on mere writing. For no one may either accuse or be accused by mere writing, but with the living voice; and every one must lay his accusation in the presence of him whom he seeks to accuse. And no credit should be given to any accuser in the absence of him whom he seeks to accuse. In like manner, witnesses must not prefer their evidence by writing only; but they must give their testimony truthfully in their own persons, and in matters which they have seen and do know. And they are not to give evidence in any other cases or matters but in those which are known to have happened in their presence. Accusers, moreover, of one blood, are not to bear witness against those who are not related to the family, nor is that to be the case with domestics (familiares) or those proceeding from the house; but if it is their wish, and they agree among themselves, the parents only should give evidence in such cases, and not others. Neither accusers nor witnesses should be admitted who are open to any suspicion; for the feeling of relationship, or friendship, or lordship, is wont to impede the truth. Carnal love, and fear, and avarice, commonly blunt the perceptions of men, and pervert their opinions; so that they look on gain as godliness, and on money as the reward of prudence. Let no one, then, speak deceitfully to his neighbour. The mouth of the malevolent is a deep pit. The innocent man, while he believes easily, falls readily; but though he falls, he rises; and the shuffler, with all his arts, goes headlong to ruin, whence he can never rise or escape. Therefore let every one weigh well his words, and let him not say to another what he would not say to himself. Whence the sacred Scripture says well: "Do not that to another which thou wouldest not have done to thyself." For we need time to do anything perfectly (maturius); and let us not be precipitate in our counsels or our works, neither let us violate order. But if any one has fallen in anything, let us not consign him to ruin; but let us reprove him with brotherly affection, as the blessed apostle says: "If a man be overtaken in any fault, ye which are spiritual restore such an one in the spirit of meekness; considering thyself, lest thou also be tempted. Bear ye one another's burden, and so will ye fulfil the law of Christ."  Furthermore, the sainted David had deadly crimes to repent of, and yet he was continued in honour. The blessed Peter also shed the bitterest tears when he repented of having denied the Lord; but still he abode an apostle. And the Lord by the prophet makes this promise to the sinning: "In the day that the sinner is converted, and repenteth, I will not mention any more against him all his transgressions." 
For those are in error who think that the priests of the Lord, after a lapse, although they may have exhibited true repentance, are not capable of ministering to the Lord, and engaging their honourable offices, though they may lead a good life thereafter, and keep their priesthood correctly. And those who hold this opinion are not only in error, but also seem to dispute and act in opposition to the power of the keys committed to the Church, whereof it is said: "Whatsoever ye shall loose on earth, shall be loosed in heaven." And in short, this opinion either is not the Lord's, or it is true. But be that as it may, we believe without hesitation, that both the priests of the Lord and other believers may return to their honours after a proper satisfaction for their error, as the Lord Himself testifies by His prophet: "Shall he who falls not also rise again? and shall he who turns away not return?" And in another passage the Lord says: "I desire not the death of the sinner, but that he may turn, and live." And the prophet David, on his repentance, said: "Restore unto me the joy of Thy salvation, and uphold me with Thy free Spirit." And he indeed, after his repentance, taught others also, and offered sacrifice to God, giving thereby an example to the teachers of the holy Church, that if they have fallen, and thereafter have exhibited a right repentance to God, they may do both things in like manner. For he taught when he said: "I will teach transgressors Thy ways, and sinners shall be converted unto Thee." And he offered sacrifice for himself, while he said: "The sacrifice for God is a broken spirit." For the prophet, seeing his own transgressions purged by repentance, had no doubt as to healing those of others by preaching, and by making offering to God. Thus the shedding of tears moves the mind's feeling (passionem). And when the satisfaction is made good, the mind is turned aside from anger. For how does that man think that mercy will be shown to himself, who does not forgive his neighbour? If offences abound, then, let mercy also abound; for with the Lord there is mercy, and with Him is plenteous redemption. In the Lord's hand there is abundance of all things, because He is the Lord of powers (virtutum) and the King of glory. For the apostle says: "All have sinned, and come short of the glory of God; being justified freely by His grace, through the redemption that is in Jesus Christ: whom God hath set forth to be a propitiation through faith in His blood, to declare His righteousness for the remission of sins that are past, through the forbearance of God; to declare, `I say,' at this time His righteousness, that He might be just, and the justifier of him which believeth in Jesus." And David says: "Blessed are they whose iniquities are forgiven, and whose sins are covered." Man, therefore, is cleansed of his sin, and rises again by the grace of God though he has fallen, and abides in his first position, according to the above-cited authorities. Let him see to it that he sin no more, that the sentence of the Gospel may abide in him: "Go, and sin no more." Whence the apostle says: "Let not sin therefore reign in your mortal body, that ye should obey the lusts thereof: neither yield ye your members as instruments of unrighteousness unto sin: but yield yourselves unto God, as those that are alive from the dead, and your members as instruments of righteousness unto God. For sin shall not have dominion over you: for ye are not under the law, but under grace. What then? shall we sin because we are not under the law, but under grace? God forbid. Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness? But God be thanked, that ye were the servants of sin; but ye have obeyed from the heart that form of doctrine which was delivered you. Being then made free from sin, ye became the servants of righteousness. I speak after the manner of men." For greater is the sin of him who judgeth, than of him who is judged. "Thinkest thou," says the apostle, "O man, that judgest them that do such things, and doest the same, that thou shalt escape the judgment of God? or despisest thou the riches of His goodness, and forbearance, and long-suffering? Dost thou not know that the goodness of God leadeth thee to repentance? But, after thy hardness and impenitent heart, thou treasurest up unto thyself wrath against the day of wrath and revelation of the righteous judgment of God; who will render to every man according to his deeds: to them who, by patient continuance in well-doing, seek for glory, and honour, and immortality, eternal life; but unto them that are contentious, and do not obey the truth, but obey unrighteousness, indignation and wrath, tribulation and anguish, upon every soul of man that doeth evil, of the Jew first, and also of the Greek: but glory, honour, and peace, to every man that worketh good." My brethren, shun not only the holding, but even the hearing, of the judgment that bans mercy; for better is mercy than all whole burnt-offerings and sacrifices. We have replied to your interrogations shortly, because your letter found us burdened overmuch, and preoccupied with other judgments. Given on the 8th day of October, in the consulship of the most illustrious Antonine and Alexander." 
E-mail to: BELIEVE
The main BELIEVE web-page (and the index to subjects) is at: BELIEVE Religious Information Source - By Alphabet http://mb-soft.com/believe/indexaz.html