Dear Paul,

Thank you for your question. Before we attempt to sort out the historical development of the chaste Priesthood in the western rite of the Church, it is important to point out that priestly celebacy is a matter of discipline rather than dogma. As such, the practice is a modus operandi, which has developed over the centuries, but is not unambiguously a product of the unbroken line of apostolic tradition and so, could be changed by the magisterium.

An opposing example of dogma versus discipline could be, for instance, the doctrine related to the ordination of women. John Paul II addressed this in the 1988 Apostolic letter "Ordinatio Sacerdotalis":
Wherefore, in order that all doubt may be removed regarding a matter of great importance, a matter which pertains to the Church's divine constitution itself, in virtue of my ministry of confirming the brethren (cf. Lk 22:32) I declare that the Church has no authority whatsoever to confer priestly ordination on women and that this judgment is to be definitively held by all the Church's faithful.

Not to digress, but, as you probaly know, these two controversies are often mentioned simultaneously and I thought it important to point out the profound difference in the underlying theological basis.

As we look at historical development, let us begin with Christ: He never married and spoke to the issue in Mt 19:3-12, concluding that "some men are incapable of sexual activity from birth; some have been deliberately made so; and some there are who have freely renounced sex for the sake of God's reign. Let him accept this teaching who can."

The catechism cites this "free renunciation of sex for the sake of God's reign", as the foundation of celibacy. However this was not practiced uniformally in the early church: Peter was married, because we know that Jesus healed his mother in law. St Paul instructs Timothy that "a bishop must be irreproachable, married only once, of even temper, self-controlled, modest and hospitable and Deacons may be married but once and must be good managers of their children and their household." 

Clement of Alexandria (died 215) agrees with St Paul: "All the same, the Church fully receives the husband of one wife whether he be priest, deacon or layman."

The council of Elvira (306) declared: "We decree that all bishops, priests, deacons and all clerics engaged in the ministry are forbidden entirely to live with their wives and to beget children." In those days, married candidates for ordination were asked to send their wives to a convent before being admitted to holy orders.

At the council of Nicea I (325) however, it was asserted that "those members of the clergy already married should remain faithful to their wives and those who were unmarried should personally decide whether or not to be celibate."

From this time forward, amongst strong partisan agitation, priestly celibacy developed organically into the norm rather than the exception, until, by the time of Pope Leo I (d.461), no bishop, priest, deacon or subdeacon could licitly live in a married state. In practicality the foregoing resulted in a plethora of clandestine and creative living arrangements involving clerics and women, following the letter of the law, but not the spirit. (Even today the proverbial "house-keeper" who never seems to leave the rectory is not an unheard of situation. 

At about this point in history (Council of Trullo 692) the eastern Church began to apply the new rule of celibacy only to bishops and this remains so today. Many priests of the oriental rite (in communion with Rome) are  married. (They must be married prior to ordination and are not free to remarry thereafter.)

It appears that celibacy in the western rite was often ignored during the middle ages, leading to ever more draconian attempts to enforce it. Pope Gregory VII in 1075 forbade "married priests, or those who had concubines to say mass or perform other ecclesiastical functions", and forbade "the laity from hearing these masses or participating in other liturgical function offered by such priests." Subsequently the first and second Lateran councils (1123 and 1139) decreed Holy Orders an impediment to marriage, making any attempt at marriage by an ordained cleric invalid.

Later, under pressure by the protestant reformation, the Council of Trent spoke with authority: "Celibacy, while not a divine law, may be imposed as a matter of discipline." (Sacrament of Orders, 1563)

The Church continues to affirm the discipline of celebacy to this day:

In the Second Vatican Council’s decree Presbyterorum Ordinis (1965), Pope Paul VI’s encyclical Sacerdotalis Caelibatus (1967), and in the Code of Canon Law (1983).

The Second Vatican Council’s Decree on the Ministry and Life of Priests (Presbyterorum ordinis) (1965) asserted, "Perfect and perpetual continence for the sake of the Kingdom of Heaven was recommended by Christ the Lord. It has been freely accepted and laudably observed by many Christians down through the centuries as well as in our own time, and has always been highly esteemed in a special way by the Church as a feature of priestly life. For it is at once a sign of pastoral charity and an incentive to it as well as being in a special way a source of spiritual fruitfulness in the world" (no. 16).

While recognizing that celibacy is not demanded by the very nature of the priesthood, the Council affirmed ways celibacy is in harmony with the priesthood: Through celibacy, a priest, identifying himself with Christ, dedicates his whole life to the service of his Lord and the Church. Celibacy enables the priest to focus entirely on building up the kingdom of God here and now. Priests can "cling to Christ with undivided hearts and dedicate themselves more freely in Him and through Him to the service of God and of men" (no. 16). They are a sign in this world of the union of the Church to her spouse, Christ, and of the life in the world to come "in which the children of the resurrection shall neither be married nor take wives" (Lk 20:35-367).

Pope Paul VI highlighted these same themes in his encyclical Sacerdotalis Caelibatus (1967), which actually was written at a time when some people questioned the need for mandatory celibacy. The Holy Father pinpointed three "significances" or senses to celibacy: the Christological, the ecclesiological and the eschatological. In the Christological sense, a priest must look to Christ as the ideal, eternal priest. This identification permeates his whole being. Just as Christ remained celibate and dedicated His life to the service of His Father and all people, a priest accepts celibacy and consecrates himself totally to serve the mission of the Lord. This total giving and commitment to Christ is a sign of the Kingdom present here and now.

In the ecclesiological sense, just as Christ was totally united to the Church, the priest through his celibacy binds his life to the Church. He is better able to be a minister of the word of God — listening to that word, pondering its depth, living it, and preaching it with whole-hearted conviction. He is the minister of sacraments, and, especially through the Mass, acts in the person of Christ, offering himself totally to the Lord. Celibacy allows the priest greater freedom and flexibility in fulfilling his pastoral work: "[Celibacy] gives to the priest, even in the practical field, the maximum efficiency and the best disposition of mind, psychologically and affectively, for the continuous exercise of a perfect charity. This charity will permit him to spend himself wholly for the welfare of all, in a fuller and more concrete way" (Sacerdotalis Caelibatus, no. 32).

Finally, in the eschatological sense, the celibate life foreshadows a freedom a person will have in heaven when perfectly united with God as His child.

The Code of Canon Law reflects these three "significances" in Canon 277, which mandates clerical celibacy: "Clerics are obliged to observe perfect and perpetual continence for the sake of the Kingdom of Heaven and therefore are obliged to observe celibacy, which is a special gift of God, by which sacred ministers can adhere more easily to Christ with an undivided heart and can more freely dedicate themselves to the service of God and mankind."

Secondly, celibacy involves sacrifice, and a sacrifice is an act of love. For instance, when a man and a woman marry, they make a sacrifice to live "in good times and in bad, in sickness and in health until death." They sacrifice to live a faithful love, no longer dating others or giving in to selfish pleasures. When they become parents, they sacrifice to support the raising of children. Decisions of love always entail sacrifice.

Our Holy Father has repeatedly defended the discipline of celibacy, calling it a "gift of the Spirit." In his Holy Thursday letter to priests in 1979 (no. 8), written at the beginning of his pontificate when some speculated he may change the discipline, he asserted, "Celibacy ‘for the sake of the kingdom’ is not only an eschatological sign; it also has a great social meaning, in the present life, for the service of the People of God. Through his celibacy, the priest becomes the man ‘for others,’ in a different way from the man, who by binding himself in conjugal union with a woman, also becomes, as husband and father, a man ‘for others,’ especially in the radius of his own family: for his wife and, together, with her, for the children, to whom he gives life. The priest, by renouncing this fatherhood proper to married men, seeks another fatherhood and, as it were, even another motherhood, recalling the words of the Apostle about the children whom he begets in suffering." Emphasizing the call of the priest to serve the People of God, the Holy Father added, ‘The heart of the priest, in order that it may be available for this service, must be free. Celibacy is a sign of a freedom that exists for the sake of service" (no. 8).

And so it is with the clergy. To be a priest means to make a sacrifice of oneself to Christ for the good of His Church. The priest sacrifices being married to a woman and having his own family to being "wedded" to Christ and His Church and serving their needs as "father."

Finally, celibacy requires the grace of God to be lived. Repeatedly, celibacy is seen as a gift of the Holy Spirit. However, this gift is not just to keep one’s physical desires under control or to live as a bachelor; this gift is being able to say "yes" to our Lord each day and live His life.

Sadly, in our world, many people cannot appreciate the discipline of celibacy, whether for the clergy or anyone else. We live in a society where the media bombards us with uncontrolled sexual imagery. If some people cannot appreciate the values of virginity before marriage, fidelity in marriage, or sacrifice for children, they cannot begin to appreciate anyone — man or woman — who lives a celibate lifestyle in dedication to a vocation.

Since the possibility of a married Priesthood exists, (an actuality in the eastern rite), the question: "Would this be a good idea?", has merit and is pertinent. While a full treatise on that subject probably belongs to another forum (Brother Ignatius hosts a very suitable possibility), here are some thoughts for consideration:

1. How difficult is it to be a biological father and a spiritual father at the same time? 

2. How would priorities be divided? (Anoint the dying person in the hospital, or assist the sick children and wife at home?)

3. Could the parish afford it? Due to the Churches position on social justice, a just family wage would have to be provided. As a point of comparison, the average jewish congregation attempting to hire a  rabbi must offer a starting wage of $110,000.00 to  135.000.00 annual plus benefits to attract a qualified individual. (Most priests earn a stipend of around 14,000.00 a year, plus housing and benefits.)

Food for thought. Incidentally, these are some of the reasons that the married priests who have converted (primarily former Anglican and Lutheran ministers) are rarely found as pastors in parish ministries. Most of these rare individuals are serving as teachers, chancery employees or hospital chaplains.

Hope this helps, God bless
Brian