With the question of clerical celibacy being in the news I thought it might be helpful to quote here a good historical summary of the antiquity of this rule in the Catholic Church. It seems to date, in some shape or form, from the very earliest recorded history of the Church when you consider that Fathers of the Church of the antiquity of say St Clement of Rome, Tertullian, Origen, Jerome, etc, all speak about it as either a rule or with approval as a practice to be encouraged in a priest. These are really the first great Fathers of the Church immediately following on from Biblical times, so if they are on board on this question we can safely say that the Church was also from the very earliest date.
But that's not to say that there were not complications in the early days. In particular you can read here how it was often debated as to whether a married man could get ordained as long as he didn't lie with his wife afterwards (which the writer below calls 'continence') and various other practices and beliefs pertained up to about 300 AD when we get the first clear laws on the subject in the Church. And of course also it develops differently in the Eastern Church, including Greece, leading to different practices there into modern times.
Anyway what follows is a good historical outline of this in The Irish Ecclesiastical Record as the writer seeks to refute some disinformation on the subject being put about by some writers of his day (particularly Thomas Olden in his 'The Church of Ireland' (London, 1892)). In particular the author addresses the question of what was the rule in the Church which St Patrick would have brought over with him into Ireland:
"Now, did clerical celibacy form part of that religious system, in which St. Patrick was trained? For, if it did, he must have introduced it into Ireland. Most assuredly it did; and this is one of the most notorious facts in ecclesiastical history.
The motive of this stringent law was, no doubt, the great purity required in those who offered up the Holy Sacrifice, and its foundation lay far back and deep down in Apostolic tradition. No one can read the New Testament without being struck by the decided preference shown in it for the celibate life. Our Blessed Lord chose for Himself, a virgin Mother, a virgin precursor, and a virgin as His most beloved disciple. His reference to those who have made themselves eunuchs for the kingdom of heaven implies a blessing on their state.
The example of St. Paul is also significant, and still more significant is his desire that all men should follow his example; whilst the vision of the virgins in the Apocalypse, "who follow the Lamb whithersoever He goeth," is a clear recognition, even in heaven, of the superior merit of virginity.
All this, of course, implied no censure on the married state, which was good in itself, and ordained and blessed by God, but it clearly implies that the state of celibacy is better, and especially in this, that because of its freedom from secular cares and family ties, it affords greater facility for the service of God. This state then specially recommended itself to the clergy, whose time should be wholly devoted to God's service. The Apostles gave up all things to follow their Divine Master, and they were deemed the fittest fellow-labourers of the Apostles, who, divested of secular cares; and living in perpetual continence, were thus a model of virtue to their flocks, and untramelled in the discharge of their sacred duties. And hence as far back as we go into the early history of the Church and on to the time of the Apostles, we shall find clerical celibacy or continence observed as a rule. At first it may have been but a custom founded on the example and encouraged by the teaching of the. Apostles, but it gradually grew into a law.
Amongst the early converts to the faith it was often difficult to find men endowed with the qualifications necessary for the responsible office of priest or bishop, and as Paganism discouraged celibacy, the difficulty of finding such a one amongst the unmarried was rendered still greater. Hence it often became necessary to ordain as priests and bishops men who had been married, provided they were within the limit laid down by St. Paul: that is, that they were only once married" the husband of one wife," and such ordinations may still be permitted for a sufficient cause, and with the precautions required by ecclesiastical law. But even in these cases the persons so ordained observed continence from the time of their ordination. Most Protestant writers, and some Catholic also, hold that priests and bishops ordained after marriage were not bound to observe continence. This opinion will be discussed later on, and it will be seen that it has no argument in its support. But though married men were thus sometimes ordained, marriage after ordination was not permitted. And so stringent was this prohibition, that there is not, at least in the Western Church, a single instance in which the marriage of a priest or bishop, after ordination, was permitted or tolerated. Will Mr. Olden consider this statement, and see whether he can refute it. In some places the obligation of celibacy extended to those even in Minor Orders, while in some few places sub-deaconship was regarded as exempt. This is the earliest stage in the history of clerical celibacy, and we find abundant evidence of it in the earliest Christian writings.
Amongst the writings attributed to St. Clement of Rome [fl. 96 AD], are the letters on Virginity, and those addressed to "James the brother of the Lord." Dr. Lightfoot denies the genuineness of those letters, though he admits that the two on Virginity, and the first to James, date from the middle of the second century. The second letter to James is, he says, as late as the fourth century. Villecourt, Beelen, and Moehler, hold the letters on Virginity to be quite genuine, and these writers are each quite as eminent as Dr. Lightfoot. And there really seems to be no solid reason for post-dating the second letter to James; it is a continuation of the first, resembling it in matter and in style. In the first letter on Virginity, the writer extols the virtue of chastity, and speaks of it as a great safeguard against the snares of the Evil One.
In the second letter he maintains, among other things, that men who have made vows of chastity should be specially on their guard against the society of persons of the opposite sex; and he describes the virtue itself as the girdle by which the loins of the priest should be bound. And in the second letter to James, he says, with reference to married priests:
This is a very decided testimony in favour of clerical continence, coming, too, according to very competent critics, from one who was a disciple of St. Peter, and certainly as early as the middle of the second century."But if it shall happen that a minister of the altar shall, after his ordination, enter the bed-room of his wife, let him not enter the sanctuary, nor be the bearer of the Holy Sacrifice."
The teaching of Tertullian [c.160 - c.225 AD] comes next in the order of time, and is equally clear on clerical continence. In his book, De Exhortatione Caxtitatis, addressed to a friend, whose wife had recently died, Tertullian wishes to dissuade his friend from a second marriage. And one of his arguments is based on the punishment inflicted on priests who would contract such marriages they would be cut off from the service of the Altar; and Tertullian warns his friend against an act that entails such penalty. He anticipates an objection that it was lawful to marry, by saying:
And he concludes the Exhortatio with these remarkable words:"Yes: It was lawful even for an Apostle to marry. It was lawful for him to live by the Gospel, but he who did not so use his right when he had occasion, calls on us to follow his own example."
And a few years later, when Tertullian was himself ordained a priest at Carthage, he proved his consistency by separating from his wife from the date of his ordination."How many are there in Ecclesiastical Orders given up to continence, who have preferred to be espoused to God, who have done honour to their flesh, putting to death in themselves concupiscence, and all that which could not be admitted into paradise." (De Ex. Cast., c. 8-13.)
The other great light of the second century is Origen [c.184- c.253 AD], and his testimony to clerical celibacy is equally clear. In his 4th Homily on Leviticus, while explaining the vestments of the Jewish priesthood, and describing the linen girdle, he applies the words to the priests of the New Law, and adds:
And in the 19th Homily on Jeremias, he so extols chastity as to claim a special glory in heaven for those who consecrate themselves to God by lives of celibacy; and by his self-mutilation, following the literal interpretation of Matt. xix. 12, he has given conclusive proof that he was terribly in earnest as an advocate of clerical celibacy. Thus, then, the earliest Christian writings that have come down to us, from post-Apostolic times, bear unequivocal testimony to the discipline of celibacy; and the writers following so closely on the Apostolic age could not be mistaken as to the tradition on the subject."For above all things, the priest who stands at God's altar must wear the girdle of chastity."
As already stated, in this early period married men may be, and many were, ordained; but they observed continence after ordination, and, if they failed to do so, they were inhibited from all priestly functions; and marriage after ordination was in no case permitted. In times of primitive fervour it was comparatively easy to maintain this rigid discipline; but as time went on fervour gradually cooled down, and we find already at the close of the third century, that great abuses had crept in, and many persons were claiming for themselves the latitude permitted by Ecclesiastical Law to those only who were in Minor Orders. We find thus early many deacons, priests, and some bishops cohabiting with the wives whom they had married before ordination, though the prohibition of marriage after ordination was still strictly observed. The abuses were prevalent mostly in the Eastern Church, though it is clear from the stringent laws subsequently passed, that the abuses began to multiply in the West also about the close of the third century. And, accordingly, we find that about this time the hitherto unwritten law was formally set forth in synodal decrees and in the language in which the abuses are condemned, we have the clearest proof of the existence of the law that was thus violated.
The first synodal law known to us on clerical celibacy is that of the Council of Elvira in Spain, A.D. 305. The 33rd Canon of that Council commands bishops, priests, and deacons who had been married to observe absolute continence, and condemns them to be degraded from their state if they disobey. The 6th Canon of the Council of Aries, A.D. 314, repeats this law in almost the same words. And while celibacy was thus rigorously enforced in the West, signs of a laxer discipline were already appearing in the East. The Synod of Ancyra, in Galatia, A.D. 314, in its 10th Canon, decreed that deacons may marry after ordination, provided that at the time of their election they notified to the ordaining bishop their intention of getting married their inability to lead a celibate life. In this case, the bishop, by ordaining them after such notice, is supposed to dispense with the law of celibacy for them; but if they receive deaconship without giving such notice, they are bound to continence, and are to be degraded if they violate their obligation. This is the earliest known synodal enactment on celibacy in the Eastern Church, and it is clearly a departure from the more ancient discipline. There is, however, no evidence that the decree prevailed outside the Province of Ancyra, and it was annulled at the Synod of Trullo. The Council of Neo-Cesarea, A.D. 317, in its 1st Canon, decreed:
Here there is question of marriage after ordination the Council says nothing of those who were married previous to ordination. The 3rd Canon of the General Council of Nice, A.D. 325, absolutely forbids a bishop, priest or deacon or any other cleric from having living with him in his house any female except his mother, sister, aunt, or some such person as is beyond all suspicion. The Canon refers especially to females called subintroductae, and writers are somewhat puzzled as to the precise character of the persons so named. They appear to have been consecrated virgins of some sort, bound to the cleric by some sort of spiritual tie, and acting somewhat in the capacity of house-keeper. The custom of permitting such persons to live with ecclesiastics was very ancient; good, perhaps, in theory, but eminently dangerous in practice, as events proved: for it led to such grave scandals as to call imperatively for the stringent legislation of Nice, and of many subsequent Councils both in the East and in the West. The Council says nothing of married or unmarried clergy, but it tends to confirm what we know to be the discipline of the Church by its supreme care to protect the clergy from even the suspicion of incontinence. The 26th of the Apostolic Canons forbids the marriage of all clerics in any higher order than that of Lector. And as these Canons date from the middle of the fourth century, they may be fairly taken as representing the discipline of that time. Some additional light is thrown on this matter by the case of Synesuis, who, in A.D. 410, refused the Bishopric of Ptolemais, on the grounds that he would not be permitted to cohabit with his wife after his consecration: a clear proof that such cohabitation was against ecclesiastical law."If a priest shall marry, he shall be cut off from the ranks of the clergy."
From this abstract of the legislation of the Eastern Church, it is certain (1) that marriage after ordination was absolutely and always forbidden (2) that many married persons were ordained as bishops, priests, and deacons; (3) that bishops were required to separate from their wives after consecration. The case of St. Gregory Nazianzen is quoted as opposed to this last statement. It is alleged that he was the son of a bishop, and born after his father's consecration. He was, it is true, the son of a bishop, but the Bollandists have proved conclusively that he was born long before his father's consecration. It has been already stated that most Protestant writers, and some Catholic, also maintain that priests and deacons married before ordination were not bound to observe continence, and they seek in the early Councils grounds to justify this opinion. The 4th Canon of the Council of Gangra [c.330 AD], in Paphlegonia [Northern Asia Minor], says:
And here we are told is a conclusive argument against the obligation of continence. But, surely, there is no foundation in this Canon for such an inference. The Canon proves what everyone admits, that there were married priests, but it says nothing as to whether they did or did not observe continence after ordination. Moreover, this precise Canon was aimed at the followers of Eustathius of Sebaste, who condemned marriage absolutely, and many of whom refused to hear Mass in the same Church as a married person. The Canon therefore proves nothing against clerical continence."If anyone shall think that one ought not assist at the Mass of a married priest, let him be excommunicated."
The same is true of the 6th of the Apostolic Canons, which is also quoted as against the obligation of continence. It says:
Here again there is nothing said for or against continence after ordination. Persons who were married before ordination were clearly bound to maintain their wives, and as the subsequent ordination did not annul the marriage, the obligation of maintaining the wife remained in full force, side by side with the obligation of continence. The two obligations are quite compatible, and the Canon is directed against those who without a justifying cause seek to escape from one of these obligations."A bishop, priest, or deacon, who on pretence of piety shall cast off his wife, shall be excommunicated, and if he persist in his rejection of her, let him be deposed."
[Leaving out here a long discussion about some statements by an ecclesiastical historian called Socrates on the Council of Nicea]
St. Epiphanius [c.315-403 AD], the Bishop of Salamis, was one of the most celebrated of the early fathers. He was about fifteen years old at the time of the Council of Nicea. He must, therefore, have been acquainted with many of those who were present at that Council. And he is known to have been an intimate personal friend of at least three of them. He was a man of great piety, learning, and ability; he was a friend and correspondent of learned men, like St. Jerome and Pope Damasus; and of ascetics like Hilarion and Pachomius. By his episcopal brethren, as well as in monastic circles, he was held in the highest veneration. In all the ecclesiastical controversies of the time, and they were many and complicated, his voice was heard with effect, and always on the side of unflinching orthodoxy. He had been many years in Palestine, was in Egypt and in Rome. He was, therefore, intimately acquainted with the discipline of East and West, and, from his character, he must be a perfectly reliable witness.
On the question of celibacy he says:
And in his book, De Haeresi speaking of married men, raised, in cases of necessity, to the priesthood, he says:"The priesthood is made up from the class of virgins, and if not of virgins, at least of those who do not cohabit with their wives; or of those who, after the death of a first wife, live in widowhood." (Exp. Doct. Christ, No. 21, 2 C. 59, N. 4.)
and, he says, the Church is most careful in the enforcement of that discipline. And he adds:"After our Lord's coming, the divine discipline excludes from the priesthood persons who had been married a second time;"
And the saint anticipates an objection thus:"And, moreover, even he who is married, and still begets children, even though the husband of one wife, is not admitted to the order of deacon, priest, bishop, or sub-deacon; but only he is to be admitted who observes continence in a first marriage, or lives in widowhood after it, which is the rule in all places where the ecclesiastical canons are duly observed."
There can be no doubt, then, that in the time of St. Epiphanius, bishops, priests, and deacons were bound to observe celibacy or continence; and its observance was not a matter of custom or free choice; they were bound to it by the ecclesiastical canons, wherever they were rightly enforced. He admits that there were abuses; but they were recognised as abuses, and are attributed to the guilty negligence of those who should have enforced the observance of the law."But you will say that in some places priests, deacons, and sub-deacons beget children. I answer: this is not on the authority of the canons, but through the culpable negligence of those who should enforce the law."
The character of Epiphanius, and his means of forming a correct judgment on this precise question render his testimony absolutely certain... St. Jerome fully confirms the testimony of Epiphanius. No one can question St. Jerome's [c.347-420] authority as a witness to the discipline of East and West. In his first letter against Vigilantius, he says:
And after condemning this conduct in no stinted terms, he says:"Alas! that this man is said to have as sharers in his guilt some bishops (if, indeed, they can be called bishops) who refuse to ordain deacons unless they be married."
The saint goes on with his wonted vehemence to say that the incontinence advocated by Vigilantius would reduce the clergy to the level of brute beasts, and leave them like hogs wallowing in the mire."What then are the Churches of the East to do? What those of Egypt? What those of the Apostolic-See, which receive among the priesthood only virgins, or continent, or those who, if married, cease to,act the husband."
It is quite easy, but quite unnecessary, to multiply testimony as to the discipline of the Oriental Church at this period. The evidence already adduced proves conclusively that celibacy for the unmarried clergy, and continence for those married before ordination, was the law. No doubt, as the saints admit, the law was violated, and in some places through the culpable negligence of bishops the Canons were not enforced, and these abuses continued notwithstanding the protests of many holy and learned bishops, until they were to some extent legalized in the Synod of Trullo. That Synod repeated the ancient prohibition of marriage after ordination. It ordered that bishops married before ordination should after consecration separate from their wives, who were to enter a convent at a distance from, the episcopal residence. And it permitted priests and deacons married before ordination to cohabit freely with their wives. This has since continued to be the law of the Greek Church; a law to which much of the degradation of that Church is justly attributable. The Canons of Trullo have been tolerated, but never sanctioned by the Holy See.
In the Western Church, under the eye of the Supreme Pastor, celibacy was from the earliest times rigorously enforced. As St. Jerome says, the circumstances of various missions often necessitated the ordination of married men, but they were strictly bound to observe continence, and no relaxation in the law was tolerated. As before stated, the law of celibacy already established by custom had its earliest written expression in the Spanish Synod of Elvira, A.D. 305, and in A.D. 314 it was repeated in the French Synod of Aries. And soon after we find it authoritatively promulgated, urbi et orbi, by Pope Siricius, A.D. 385, in his letter to Heimerius, Bishop of Tarragona, in Spain. This bishop had in the previous year sent to Pope Damasus what appears to have been a regular relatio status of his diocese (Siricius in his reply calls it " Fraternitatis tuae relatio "). He disclosed to the Pope the existence of several abuses in his diocese, and sought instruction as to how they were to be remedied.
One of his difficulties was that some priests and deacons led incontinent lives, and sought to justify their misconduct by the example of the priests of the old law. Pope Damasus was dead when the letter reached Rome, and the reply to it was one of the first official acts of the new Pope Siricius [Pope from 384-399 AD]. The Pope laments that anyone of the ecclesiastical order should be open to the charges brought against them by the bishop. In vain, he says, do they appeal to the example of the Jewish priests, to whom marriage was permitted, that, the succession of the priesthood may be preserved in the tribe of Levi; and even they were warned to be holy, as the Lord their God was holy, and were bound to live in the temple, and to observe continence during their year of ministration:
..."Wherefore [the Pope says], since our Lord Jesus honoured us by His coming, He declares in the Gospel that He has come to perfect the law; and, accordingly, He wished to show forth in His Church the beauty of chastity, that, on His second coming, she may be found, as the Apostle describes her, without spot or wrinkle; on which account we, priests, are all bound by an inviolable law to observe, from the day of our ordination, moderation and continence, that we may in all things please God by the sacrifice which we daily offer to Him . . . And as there are some, as your Holiness says, who are sorry for their guilt, and plead ignorance, we decree that mercy shall be extended to them to this extent, that they shall be permitted to remain in their present rank, without any hope of promotion, provided, however, that they live in strict continence for the future. But as to those who persevere in their sin, and rely on the Old Law for their justification, be it known to them that, by the authority of the Apostolic See, they are degraded from all ecclesiastical honours, of which they have shown themselves unworthy; and that they shall never touch again the Sacred Mysteries, of which, for the sake of impure pleasures, they have deprived themselves. And the instances we are now considering warn us to take precaution for the future . . . Be it known to every bishop, priest, and deacon, who shall be found so guilty, that they are to expect no indulgence from us; for the wounds that do not yield to soothing medicine, must be cut out with the knife."
Again, Heimerius, in his letter, complained of their conduct to the Pope, and the letter of Siricius is the answer to that complaint. But if up to that time there had been no law rendering celibacy obligatory, there would be no ground for the complaint, nor any justification for the punishment decreed. Moreover, the Pope distinctly says: "Wherefore we priests are bound by an inviolable law," &c-
This is a law already existing, not the framing of a new law; and if there had not been a law of celibacy well recognised as obligatory, we could not explain that strictness in its observance so rigidly uniform, that there is not a single instance at least in the Western Church of a bishop, priest, or deacon permitted with impunity to depart from its observance. The synods already quoted prove the existence of the law long before the letter of Pope Siricius. The 2nd Council of Carthage, A.D. 387; the 1st of Toledo, A.D. 400; the 3rd of Carthage, A.D. 401 all promulgate the law contained in the letter of Pope Siricius. Pope Innocent 1, in A.D. 405, wrote his two celebrated letters to Victricius of Rouen, and Exuperius of Toulouse, laying down the law on celibacy, in almost the same words as Pope Siricius. Leo the Great, in a letter to Rusticus, Bishop of Narbonne, and Gregory the Great, in his letter to Leo, Bishop of Catania, promulgate the same law as Siricius, and extend its obligation to subdeacons, who were in some places considered hitherto exempt on the ground that their duties did not bring them into immediate contact with the Holy Sacrifice of the Mass.
And at the Council of Agde, A.D. 506, and at several other councils of the same period, we find regulations made binding even those in minor orders to observe continence, and refusing them even clerical tonsure if they do not promise to observe it.
Such was the discipline of celibacy when St. Patrick came to Ireland. It was a rigid law, stringently enforced on all persons in Holy Orders, faithfully observed by every priest worthy of his sacred character, and never violated with impunity by anyone. And at the very time of St. Patrick's coming this law was being extended so as to embrace even those in minor orders, and so to exclude all but celibates from the service of the Church. A married man may at that time be ordained, as he may now even, pre-supposing the conditions required by Canon Law. But such a person, then as well as now, was bound to observe continence, and would be punished then as well as now if he were found unfaithful to his obligation. And then as well as now marriage after ordination was not to be thought of. This was the discipline in which St. Patrick was trained."
(J Murphy, Recent Protestant Historians of Ireland, published in the Irish Ecclesiastical Record, vol 17, 1896, p.490 et seq.