In the teaching of the Roman Catholic Church, the Sacrament of Penance (commonly called Confession, Reconciliation or Penance) is the method given by Christ to the Church by which individual men and women may be freed from sins committed after receiving Baptism. (It is not necessary to confess sins committed before baptism, as baptism itself is considered to remove the guilt of all prior sins.) This sacrament is known by many names, including penance, reconciliation, and confession (Catechism of the Catholic Church, Sections 1423-1442). Official Church publications of the Latin-rite always refer to the sacrament as "Penance," or "Reconciliation" or "Penance and Reconciliation." However, many lay Catholics continue to use the term "confession" in reference to the sacrament.
In 1215, a requirement that every Roman Catholic Christian receive this sacrament at least once a year was instituted in Canon 21, the famous "Omnis utriusque sexus", of the Canon Law at the Fourth Council of the Lateran. 
Minister of the Sacrament
Roman Catholics believe that no priest, as an individual man, however pious or learned, has the power to forgive sins apart from God. However, the priest does not merely announce that the penitent has received God's forgiveness. Rather, it is in fact the priest himself who, by reciting the formula of absolution, forgives the sins of the penitent in God's place. Thus, God can and does accomplish the forgiveness of sins through the Roman Catholic priesthood in the Sacrament of Penance, which is validly administered by any validly ordained priest or bishop having jurisdiction to absolve the penitent. In fact, in danger of death or in serious ill health, because of the importance of the sacrament for one's salvation, a priest (who has not been excommunicated, laicized, or suspended 'a divinis'- in other words, who has not had all his sacramental faculties revoked) who would not otherwise have the faculties to hear confessions can still absolve the person. It is also true that even if a person has unconfessed mortal sins remaining when he or she dies, they may still hope to be forgiven if before they died, they expressed true contrition (sorrow) for each of their mortal sins and if, having done so, they expressed a desire (even if not possible) to go to sacramental confession and do proper penance and restitution. This exception is based on the belief that God, in his love and mercy and in his utmost desire for all to be saved, knowing that they are sorry will allow them to formally apologize and make reparation (in some way) when they are judged. However, if they are able to make a valid sacramental confession before death, they are required to do so, as that is the ordinary way to be reconciled to God.
Form of the Sacrament
The form of Penance has not changed for centuries, although at one time confessions were made publicly. The role of the priest is as a minister of Christ's mercy. He acts in persona Christi. In the Roman Catholic tradition, after making an examination of conscience that often involves review of the Ten Commandments, the penitent confesses mortal sins in order to restore his relationship to God and to receive the fullness of God's grace and salvation. The sinner may as a pious matter confess venial sins, especially if the sinner has no mortal sins to confess. The intent of this sacrament is to provide healing for the soul as well as to regain the grace of God, lost by sin. The Council of Trent (Session Fourteen, Chapter I) quoted John 20:22-23 as the primary Scriptural proof for the doctrine concerning this sacrament, but Catholics also consider Matthew 9:2-8 and 2 Corinthians 5:17-20 to be among the Scriptural bases for the sacrament.
The words of Absolution in the Latin Rite take this form:
God the Father of mercies, through the death and resurrection of his Son, has reconciled the world to Himself and sent the Holy Spirit among us for the forgiveness of sins; through the ministry of the Church may God give you pardon and peace, and I absolve you from your sins in the name of the Father, and of the Son, and of the Holy Spirit.
The essential words, however, are: "I absolve you from your sins."
The penitent makes an act of contrition, a prayer acknowledging his/her faults before God. It typically commences: O my God, I am heartily sorry... Reconciliation is necessary before receiving the sacrament of Eucharist for the first time. The Catholic Church teaches that the Sacrament of Reconciliation is the only ordinary way in which a person can receive forgiveness for mortal sins committed after baptism. However, perfect contrition (a sorrow motivated by love of God rather than of fear of punishment) is an extraordinary way of removing the guilt of mortal sin before or without confession (if there is no opportunity of confessing to a priest). Such contrition would include the intention of confessing.
Making an act of contrition (and receiving absolution and performing the penance) to one's confessor or another priest, even if he gives advice during the sacrament, is separate from pastoral counseling or psychotherapy given by the priest- even if he is the confessor or spiritual director of the client or is a member of the pastoral team at the client's parish church. The members of the hierarchy of the Catholic Church have insisted on this point in order to avoid confusion, as both confidential processes have distinct and important roles in church life.
For Validity of the Sacrament: Matter and form
According to St. Thomas (Summa Theologiæ III.74.2) "the acts of the penitent(namely contrition, confession, and satisfaction) are the proximate matter of this sacrament". This is also the teaching of Eugenius IV in the "Decretum pro Armenis" (Council of Florence, 1439) which calls the act's "quasi materia" of penance and enumerates them as contrition, confession, and satisfaction (Denzinger-Bannwart, "Enchir.", 699).
The Thomists in general and other eminent theologians, e.g., Bellarmine, Toletus, Francisco Suárez, and De Lugo, hold the same opinion. According to Scotus (In IV Sent., d. 16, q. 1, n. 7) "the Sacrament of Penance is the absolution imparted with certain words" while the acts of the penitent are required for the worthy reception of the sacrament.
The absolution as an external ceremony is the matter, and, as possessing significant force, the form.
The Council of Trent (Sess. XIV, c. 3) declares: "the acts of the penitent, namely contrition, confession, and satisfaction, are the quasi materia of this sacrament". The Roman Catechism used in 1913 (II, v, 13) says: "These actions are called by the Council quasi materia not because they have not the nature of true matter, but because they are not the sort of matter which is employed externally as water in baptism and chrism in confirmation".
Regarding the form of the sacrament, both the Council of Florence and the Council of Trent teach that it consists in the words of absolution. "The form of the Sacrament of penance, wherein its force principally consists, is placed in those words of the minister: "I absolve thee, etc."; to these words indeed, in accordance with the usage of Holy Church, certain prayers are laudably added, but they do not pertain to the essence of the form nor are they necessary for the administration of the sacrament" (Council of Trent, Sess. XIV, c. 3). Concerning these additional prayers, the use of the Eastern and Western Churches, and the question whether the form is deprecatory or indicative and personal
Frequency of reception
The Code of Canon Law requires all Roman Catholics to confess mortal sins at least once a year, although frequent reception of the sacrament is recommended. Traditionally, the sacrament has been received during the liturgical seasons of Lent or Advent, or prior to special times in life such as confirmation or marriage. While some branches of the Catholic Church do not require confession to be completed on any set schedule, the Latin rite requires that its practitioners confess at least once a year. This is commonly known as the second precept of the Church. There is evidence from the UK and USA that at least three-quarters of professed Roman Catholics do not adhere to this requirement of canon law.
Frequent confession has been recommended by Popes. Confession of everyday faults is "strongly recommended by the Church." (CCC 1458) According to Pius XII and Pope John XXIII, "We particularly recommend the pious practice of frequent confession, which the Church has introduced, under the influence of the Holy Spirit, as a means of swifter daily progress along the road of virtue." Paul VI said that frequent confession is "of great value."
- we are renewed in fervor,
- strengthened in our resolutions, and
- supported by divine encouragement
Because of what he considered misinformation on this topic, he strongly recommended this practice and warned that those who discourage frequent confession "are lying."
Seal of confession
For Catholic priests, the confidentiality of all statements made by penitents during the course of confession is absolute. This strict confidentiality is known as the Seal of the Confessional. According to the Code of Canon Law, 983 §1, "The sacramental seal is inviolable; therefore it is absolutely forbidden for a confessor to betray in any way a penitent in words or in any manner and for any reason." Priests may not reveal what they have learned during confession to anyone, even under the threat of their own death or that of others. This is unique to the Seal of the Confessional. Many other forms of confidentiality, including in most states attorney-client privilege, allow ethical breaches of the confidence to save the life of another. A priest who breaks that confidentiality incurs latae sententiae (automatic) excommunication reserved to the Holy See (Code of Canon Law, 1388 §1). In a criminal matter, a priest may encourage the penitent to surrender to authorities- in some cases, this can be made a condition of absolution as part of one's penance. However, this is the extent of the leverage he wields; he may not directly or indirectly disclose the matter to civil authorities himself.
There are limited cases where portions of a confession may be revealed to others, but always with the penitent's permission and always without actually revealing the penitent's identity. This is the case, for example, with unusually serious offenses, as some excommunicable offenses are reserved to the bishop or even to the Holy See, and their permission to grant absolution would first have to be obtained. There are certain procedures that have been formally set by the Church and civil governments that apply, without violating the seal of confession, if the penitent is a priest or other church official and is guilty of a civil crime involving the sexual exploitation or abuse of minors. These were instituted out of necessity during the sex abuse crises in the American church and in other countries.
It is worth noting that the Sacramental seal can bring penalties if misuse is attempted.
With due regard for c.1388, whoever by any technical instrument records or publishes in the mass media what was said in the sacramental confession by the confessor or the penitent, real or feigned, by him/herself or another person, incurs a latae sententiae excommunication. This decree goes into effect the day of promulgation.
Civil authorities in the United States are usually respectful of this confidentiality. However, in 1996, an attorney in Portland, Oregon secretly recorded a confession without the knowledge of the priest or the penitent involved. This led to official protests by then local Archbishop Francis George and the Holy See. The tape has since been sealed (and later destroyed), and the Federal Court has since ruled that the taping was in violation of the Fourth Amendment to the United States Constitution, and ordered an injunction against any further tapings.
The Manuals of confession in the Middle Ages
In the Middle Ages the manuals of confession constituted a literary genre. These manuals were guidebooks on how to obtain the maximum benefits from the sacrament. There were two kinds of manuals: those addressed to the faithful, so that they could prepare a good confession, and those addressed to the priests, who had to make sure that no sins were left unmentioned and the confession was as thorough as possible. The priest had to ask questions, while being careful not to suggest sins that perhaps the faithful had not thought of and give them ideas. Manuals were written in Latin and in the vernacular. See http://www.fordham.edu/halsall/projects/arroyo/manuels.htm (in French) about manuals of confession in medieval Spain.
In general practice, after one confesses to one's spiritual guide, the parish priest (Who may or may not have heard the confession but canonically should have) covers the head of the person with his Epitrachelion (Stole) and reads the prayers of repentance, asking God to forgive the transgression of the individual.
- ↑  Fourth Lateran Council
- ↑ can. 959, CIC 1983
- ↑ can. 966, CIC 1983
- ↑ can. 960. CIC 1983
- ↑ can. 960 CIC 1983
- ↑ Catechism of the Catholic Church #2041-2043
- ↑ http://www.thetablet.co.uk/article/5358
- ↑ http://cara.georgetown.edu/reconciliation.pdf
- ↑ The Spiritual and Psychological Value of Frequent Confession by Fr. John Hardon
- ↑ Congregation for the Doctrine of the Faith, Decree, Congregatio pro Doctina Fidei in AAS 80 (1988) p 1367, quoted in Sacraments: Initiation, Penance, Anointing of the Sick Woestman, WM, Ottawa 2004, pg 277