Imagine the following scenario: The world famous Roman TV host Jacobi Fallonis interviews Cardinal Tristus regarding the state of the Sacrament of Penance upon his return from the Council of Trent, 25 November 1551.
Think about this: "If a sailor on one of Columbus' ships had gone to confession before leaving land, and if an astronaut in the space program had gone to confession before leaving earth, they both would have used the same rite of penance." (Martos, Doors 2014, p xii)
Osborne, "Reconciliation and Justification at the Council of Trent," pp 157-197.
Trent, November 1551: "Those who have mortal sin on their conscience, no matter how contrite they may think they are, must necessarily make a sacramental confession before receiving the Eucharist, provided that they have access to a confessor." (Denzinger 893. Quoted by Hay, p 91.)
CIC Canon 916. (ed 1983) A person who is conscious of grave sin is not to celebrate Mass or received the Body of the Lord without previous sacramental confession unless there is a grave reason and there is no opportunity to confess; in this case the person is to remember the obligation to make an act of perfect contrition which includes the resolution of confessing as soon as possible.
Understanding the Canon. See: Fontes: cc. 807, 856; EMys 35; SCDF Normae Pastorales, 16 iun. 1972, prooemium et VI (AAS 64 510, 512); CEM 23.
This canon is found in the 1917 Code of Canon Law, canon 807: "A priest who is conscious of the fact that there is a mortal sin on his soul shall not dare to say Mass without previous confession, however contrite he may esteem himself to be ..." Commentary: e.g. Woywod, page 479-480] and canon 856 ["Nobody who is conscious of having a mortal sin on his soul shall go to Holy Communion before making a sacramental confession, no matter how contrite he may believe..." Commentary: e.g. Woywod, page 525, Footnote reference to Trent, Session XIII, Chapter VII]. EMys 35; SCR Instr. Eucharisticum mysterium, 25 Maii 1967 (AAS 58  817-835. [AAS = Acta Apostolicae Sedis, Commentarium officiale]
SCDF Normae Pastorales, 16 iun. 1972, prooemium et VI (AAS 64 510, 512);
De Sacra Communione et de Cultu Mysterii Eucharistici extra Misssam, 1973, #23.
Commentary on canon 916 in the Canon Law Society of America, The Code of Canon Law: A Text and Commentary. New York: Paulist Press. 1985, p 653.
Questions theologians are asking today.
1. What of this is "de jure divino" and what is "of Church law" (and hence, reformable, law)?
2. What constitutes a "grave reason" in canon 916? Axiom: "Burdens are to be restricted; favors are to be multiplied." (Boniface VIII, De regulis iuris, rule 15). Canon 960 speaks of being excused because of "physical or moral impossibility." Physical -- e.g. too sick to get to a priest; Moral -- e.g. the person has had an experience in confession with a priest who abused the sacrament and the person is now too scared to try it again. What is possible and what is prudent? -- e.g. confessing to your boss, spouse, etc. What constitutes "grave sin"? Are there shades of distinction between "grave," "mortal," "serious," and 'venial" sins?
3. Why (and how) can we say that an act of perfect contrition "includes the resolution of confessing as soon as possible"? (Canon 916) If the sin is already forgiven [by eucharist, or by general absolution] why does one need to confess the sin? Does this "confession" have to be in the sacrament of reconciliation or can it be done in a non-sacramental forum? (Note the implications for Rite III.)
4. What does "quam primum" [as soon as possible] mean in this situation? Three days? What if a communal celebration is only offered during Advent and Lent in the parish?
5. How worthy does one have to be to receive Eucharist? [See Dallen, p 55 n 14.]
Eucharist as Sacrament of Reconciliation
1. "While they were eating, Jesus took a loaf of bread, and after blessing it he broke it, gave it to the disciples, and said, 'Take, eat; this is my body.' Then he took a cup, and after giving thanks he gave it to them, saying, 'Drink from it, all of you; for this is my blood of the covenant, which is poured out for many for the forgiveness of sins.'" (Matthew 26:26-28.)
2. "It is evident that the Eucharist is seen as a great moment of reconciliation. ... Indeed, the Eucharist, next to Jesus and the Church is the sacrament of reconciliation, not the sacrament of penance, not even the sacrament of baptism. The Eucharist, because of the centrality of Jesus, must be seen as the sacrament of reconciliation. (Osborne, p 171.)
3. "There is no indication in more than a thousand years of the Church's history that the Eucharist could indeed forgive venial sins but only the sacrament of penance could forgive mortal sins." (Leo Hay, Eucharist: A Thanksgiving Celebration, Glazer, The Liturgical Press, 1989, p 87.)
4. Lex Orandi Legem Credendi Constituit: Catholics hear, Sunday after Sunday, "May almighty God . . . forgive us our sins." (Penitential Rite) "You take away the sin of the world: have mercy on us." (Glory to God) "Though we are sinners, we trust in your mercy and love. Do not consider what we truly deserve, but grant us your forgiveness." (Eucharistic Prayer I) "Our Father . . . forgive us our trespasses as we forgive those who trespass against us." (Lord's Prayer) "This is the Lamb of God who takes away the sins of the world . . . . Lord, I am not worthy . . . but only say the word and I shall be healed." (Invitation to Communion). And at the heart of each and every Eucharistic prayer in the institution narrative we hear Christ's command to "Take this, all of you, and drink from it: this is the cup of my blood, ... It will be shed for you and for all so that sins may be forgiven." These are only a few of many references to the forgiveness of sins at Eucharist. (Not to mention the theology of BRK and the epiclesis for Unity (forgiveness) followed by the 3 reconciliation acts at each eucharist.)
Sacramental Readiness: e.g. The parable of "The Man With Two Sons" (Luke 15:11-32). After the younger son returned, he was daily invited to the common table; but first there needed to be a special celebration, welcoming his return = Sacrament of Reconciliation.
Sign value of seeing others; group support; Communion of Saints; (Former terminology of "confession of devotion"); both human forgiveness and human reconciliation are process.
1. The absolute gratuity of God's grace
2. The complete adequacy of Jesus' redemptive act
3. The issue of Faith
4. The process of justification
5. Good works