The Sacrament of Holy Orders in the modern Catholic Church includes 3 degrees:
- priests, and
- definition of "order"
The word ordo in Latin designated an established civil body or corporation, and ordinatio meant legal incorporation into an ordo. The 3 degrees of Holy Orders represent ordines.
- meaning of priesthood
The Catholic church sees its priesthood as both a reflection of the ancient temple priesthood of the Jews and the person of Christ. The liturgy of ordination recalls the the Old Testament priesthood and the priesthood of Christ. In the words of St. Thomas Aquinas, "Christ is the source of all priesthood: the priest of the old law was a prefiguration of Christ, and the priest of the new law acts in the person of Christ" [Summa Theologica III, 22, 4c].
- process and sequence
The arrangement given above, "bishops, priests, and deacons" is in the reverse order of ordination. Typically in the last year of seminary training a man will be ordained to the diaconate, called in recent times the "transitional diaconate" to distinguish men bound for priesthood from those who have entered the "permanent diaconate" and do not intend to seek further ordination. Deacons, whether transitional or permanent, are licensed to preach sermons, to perform baptisms, and to witness marriages, but to perform no other sacraments. They may assist at the Eucharist or the Mass, but are not the ministers of the Eucharist.
After a year or more as a transitional deacon a man will be ordained to the priesthood. Priests are able to preach, perform baptisms, witness marriages, hear confessions and give absolutions, and celebrate the Eucharist or the Mass.
- marriage and holy orders
Married men may be ordained to the diaconate as Permanent Deacons, but in the Latin Rite of the Catholic Church may not be ordained to the priesthood. In the Eastern Rites of the Catholic Church and in the Eastern Orthodox Church married deacons may be ordained priests, but may not become bishops. Bishops in the Eastern Rites and the Eastern Orthodox churches are drawn only from among monks, who have taken a vow of celibacy.
There are cases of permanent deacons who, left widowed by the death of a wife, have been ordained to the priesthood. There have been some situations in which men previously married and ordained to the priesthood in the Anglican Church have been admitted to the Catholic priesthood and allowed to function much as an Eastern Rite priest but in a Latin Rite setting.
- chastity and celibacy
The differences between chastity and celibacy are poorly understood. Celibacy is the state of not being married. So a vow of celibacy is a promise not to enter into marriage but instead to consecrate one?s life to service. Chastity is a virtue expected of all Christians and is the state of sexual purity; for a vowed celibate or for the single person, chastity would mean the avoidance of sex. For the married person, chastity would mean the practice of sex only with the spouse. In fact, married chastity carries the expectation of intercourse with the spouse.