I cannot better express the doctrine and practice of the ancient Church in the East than by quoting the words of the Rev. John Fulton in the Introduction to the Third Edition of his Index Canonum.  He says: "Marriage was no impediment to ordination even as a Bishop; and Bishops, Priests, and Deacons, equally with other men, were forbidden to put away their wives under pretext of religion. The case was different when a man was unmarried at the time of his ordination. Then he was held to have given himself wholly to God in the office of the Holy Ministry, and he was forbidden to take back from his offering that measure of his cares and his affections which must necessarily be given to the maintenance and nurture of his family. In short, the married man might be ordained, but with a few exceptions no man was allowed to marry after ordination." In his "Digest" sub voce "Celibacy" he gives the earliest canon law on the subject as follows: "None of the clergy, except readers and singers may marry after ordination (Ap. Can. xxvi.); but deacons may marry, if at their ordination they have declared an intention to do so (Ancyra x.). A priest who marries is to be deposed (Neocæsarea i.). A deaconess who marries is to be anathematized (Chal. xv.); a monk or dedicated virgin who marries, is to be excommunicated (Chal. xvi.). Those who break their vows of celibacy are to fulfil the penance of digamists (Ancyra xix.)." 
We may then take it for a general principle that in no part of the ancient Church was a priest allowed to contract holy matrimony; and in no place was he allowed to exercise his priesthood afterwards, if he should dare to enter into such a relation with a woman. As I have so often remarked it is not my place to approve or disapprove this law of the Church, my duty is the much simpler one of tracing historically what the law was and what it is in the East and West to-day. The Reformers considered that in this, as in most other matters, these venerable churches had made a mistake, but neither the maintenance nor the disproof of this opinion in any way concerns me, so far as this volume is concerned. All that is necessary for me to do is to affirm that if a priest were at any time to attempt to marry, he would be attempting to do that which from the earliest times of which we have any record, no priest has ever been allowed to do, but which always has been punished as a gross sin of immorality.
In tracing the history of this subject, the only time during which any real difficulty presents itself is the first three centuries, after that all is much clearer, and my duty is simply to lay the undisputed facts of the case before the reader.
We begin then with the debatable ground. And first with regard to the Lord, "the great High Priest of our profession," of course there can be no doubt that he set the example, or -- if any think that he was not a pattern for the priests of his Church to follow -- at least lived the life, of celibacy. When we come to the question of what was the practice of his first followers in this matter, there would likewise seem to be but little if any reasonable doubt. For while of the Apostles we have it recorded only of Peter that he was a married man, we have it also expressly recorded that in his case, as in that of all the rest who had "forsaken all" to follow him, the Lord himself said, "Every one that hath forsaken houses, or brethren, or sisters, or father, or mother, or wife, or children, or lands, for my name's sake shall receive an hundred fold and shall inherit eternal life." 
There can be no doubt that St. Paul in his epistles allows and even contemplates the probability that those admitted to the ranks of the clergy will have been already married, but distinctly says that they must have been the "husband of one wife,"  by which all antiquity and every commentator of gravity recognizes that digamists are cut off from the possibility of ordination, but there is nothing to imply that the marital connexion was to be continued after ordination. For a thorough treatment of this whole subject from the ancient and Patristic point of view, the reader is referred to St. Jerome. 
The next stage in our progress is marked by the so-called Apostolical Canons. Now for those who hold that these canons had directly or indirectly the Apostles for their author, or that as we have them now they are all of even sub-Apostolic date, the matter becomes more simple, for while indeed these canons do not expressly set forth the law subsequently formulated for the East, they certainly seem to be not inconsistent therewith, but rather to look that way, especially Canons V. and LI. But few will be found willing to support so extreme an hypothesis, and while indeed many scholars are of opinion that most of the canons of the collection we style "Apostolical," are ante-Nicene, yet they will not be recognized as of more value than as so many mirrors, displaying what was at their date considered pure discipline. It is abundantly clear that the fathers in council in Trullo thought the discipline they were setting forth to be the original discipline of the Church in the matter, and the discipline of the West an innovation, but that such was really the case seems far from certain. Thomassinus treats this point with much learning, and I shall cite some of the authorities he brings forward. Of these the most important is Epiphanius, who as a Greek would be certain to give the tradition of the East, had there been any such tradition known in his time. I give the three great passages.
"It is evident that those from the priesthood are chiefly taken from the order of virgins, or if not from virgins, at least from monks; or if not from the order of monks, then they are wont to be made priests who keep themselves from their wives, or who are widows after a single marriage. But he that has been entangled by a second marriage is not admitted to priesthood in the Church, even if he be continent from his wife, or be a widower. Anyone of this sort is rejected from the grade of bishop, presbyter, deacon, or subdeacon. The order of reader, however, can be chosen from all the orders these grades can be chosen from, that is to say from virgins, monks, the continent, widowers, and they who are bound by honest marriage. Moreover, if necessity so compel, even digamists may be lectors, for such is not a priest, etc., etc." 
"Christ taught us by an example that the priestly work and ornaments should be communicated to those who shall have preserved their continency after a single marriage, or shall have persevered in virginity. And this the Apostles thereafter honestly and piously decreed, through the ecclesiastical canon of the priesthood." 
"Nay, moreover, he that still uses marriage, and begets children, even though the husband of but one wife, is by no means admitted by the Church to the order of deacon, presbyter, bishop, or subdeacon. But for all this, he who shall have kept himself from the commerce of his one wife, or has been deprived of her, may be ordained, and this is most usually the case in those places where the ecclesiastical canons are most accurately observed." 
Nor is the weight of this evidence lessened, but much increased, by the acknowledgment of the same father that in some places in his days the celibate life was not observed by such priests as had wives, for he explains that such a state of things had come about "not from following the authority of the canons, but through the neglect of men, which is wont at certain periods to be the case." 
The witness of the Western Fathers although so absolutely and indisputably clear is not so conclusive as to the East, and yet one passage from St. Jerome should be quoted. "The Virgin Christ and the Virgin Mary dedicated the virginity of both sexes. The Apostles were chosen when either virgins or continent after marriage, and bishops, presbyters, and deacons are chosen either when virgins, or widowers, or at least continent forever after the priesthood." 
It would be out of place to enter into any detailed argument upon the force of these passages, but I shall lay before the reader the summing up of the whole matter by a weighty recent writer of the Ultramontane Roman School.
"Is the celibate an Apostolic ordinance? Bickel affirmed that it is, and Funk denied it in 1878. To-day  canonists commonly admit that one cannot prove the existence of any formal precept, either divine or apostolic, which imposes the celibate upon the clergy, and that all the texts, whether taken out of Holy Scripture or from the Fathers, on this subject contain merely a counsel, and not a command." "In the Fourth Century a great number of councils forbade bishops, priests, and deacons to live in the use of marriage with their lawful wives....But there does not appear to have been any disposition to declare by law as invalid the marriages of clerics in Holy Orders. In the Fifth and Sixth Centuries the law of the celibate was observed by all the Churches of the West, thanks to the Councils and to the Popes." "In the Seventh and down to the end of the Tenth Century,  as a matter of fact the law of celibacy was little observed in a great part of the Western Church, but as a matter of law the Roman Pontiffs and the Councils were constant in their proclamation of its obligation." By the canonical practice of the unreformed West, the reception of Holy Orders is an impedimentum dirimens matrimonii, which renders any marriage subsequently contracted not only illicit but absolutely null. On this diriment impediment the same Roman Catholic writer says: "The diriment impediment of Holy Orders is of ecclesiastical obligation and not of divine, and consequently the Church can dispense it. This is the present teaching which is in opposition to that of the old schools."
"There is no question of the nullity of the marriages contracted by clerics before 1139. At the Council of the Lateran of that year, Innocent II. declared that these marriages contracted in contempt of the ecclesiastical law are not true marriages in his eyes. His successors do not seem to have insisted much upon this new diriment impediment, although it was attacked most vigorously by the offending clergymen; but the School of Bologna, the authority of which was then undisputed, openly declared for the nullity of the marriages contracted by clerics in Holy Orders. Thus it is that this point of law has been settled rather by teaching, than by any precise text, or by any law of a known date." 
It should not, however, be forgotten that although this is true with regard to Pope Innocent II. in 1139, it is also true that in 530 the Emperor Justinian declared null and void all marriages contracted by clerics in Holy Orders, and the children of such marriages to be spurious (spurii).
The reader will be interested in reading the answer on this point made by King Henry VIII. to the letter sent him by the German ambassadors.  I can here give but a part translated into English. "Although the Church from the beginning admitted married men, as priests and bishops, who were without crime, the husband of one wife, (out of the necessity of the times, as sufficient other suitable men could not be found as would suffice for the teaching of the world) yet Paul himself chose the celibate Timothy; but if anyone came unmarried to the priesthood and afterwards took a wife, he was always deposed from the priesthood, according to the canon of the Council of Neocæsarea which was before that of Nice. So, too, in the Council of Chalcedon, in the first canon of which all former canons are confirmed, it is established that a deaconess, if she give herself over to marriage, shall remain under anathema, and a virgin who had dedicated herself to God and a monk who join themselves in marriage, shall remain excommunicated....No Apostolic canon nor the Council of Nice contain anything similar to what you assert, viz.: that priests once ordained can marry afterwards. And with this statement agrees the Sixth Synod, in which it was decreed that if any of the clergy should wish to lead a wife, he should do so before receiving the Subdiaconate, since afterwards it was by no means lawful; nor was there given in the Sixth Synod any liberty to priests of leading wives after their priesting, as you assert. Therefore from the beginning of the newborn Church it is clearly seen that at no time it was permitted to a priest to lead a wife after his priesting, and nowhere, where this was attempted, was it done with impunity, but the culprit was deposed from his priesthood."
 John Fulton, Index Canonum, p. 29 (N.Y., 1892.)  Ibid., p. 294.  Hieron, Adv. Jovin. Lib. I. Confer also the In Apolog. pro libris Adv. Jovin.  Epiph. Exposit. Fid. Cath., c. xxi.  Ibid. Hæresi. 48, n. 7.  Epiph. Hæresi, 59, n. 4.  Ibid. ut supra.  Hieron. Apolog. pro. lib. adv. Jovin.  It is curious that this is just four centuries, the same length of time as from the Reformation.  L'Ami du Clergé, 6 Août, 1896, pp. 677 and 678.  This letter is found in full in the Addenda to the Appendix at the end of the seventh volume of Burnet's History of the Reformation (London. Orr & Co., 1850, p. cxlviij.).
 Ibid., p. 294.
 Hieron, Adv. Jovin. Lib. I. Confer also the In Apolog. pro libris Adv. Jovin.
 Epiph. Exposit. Fid. Cath., c. xxi.
 Ibid. Hæresi. 48, n. 7.
 Epiph. Hæresi, 59, n. 4.
 Ibid. ut supra.
 Hieron. Apolog. pro. lib. adv. Jovin.
 It is curious that this is just four centuries, the same length of time as from the Reformation.
 L'Ami du Clergé, 6 Août, 1896, pp. 677 and 678.
 This letter is found in full in the Addenda to the Appendix at the end of the seventh volume of Burnet's History of the Reformation (London. Orr & Co., 1850, p. cxlviij.).