Doctrine of the Catholic Church often greatly misunderstood both by non-Catholics and Catholics is that of Indulgences. As a result of these misunderstandings many erroneous opinions have been set forth on the matter, resulting in countless attacks being made upon the Church by her adversaries.
The word indulgence, from the Latin indulgere, originally meant complaisance, mercy or favor. Later in post-classical Latin it came to mean the remission of debts or punishments, while in Scripture and Roman Law the term was generally used to designate the release from captivity or punishment. In early ecclesiastical usage the word had almost as many meanings as it had in profane use. Gradually, however, its meaning came to be restricted, so that in the twelfth century we find an indulgence meaning the remission of the temporal punishment due to sin. This same meaning is preserved in the New Code of Canon Law where we find an indulgence defined as "the remission before God of the penalty due to sin already forgiven, which the ecclesiastical authority grants out of the treasury of the Church, to the living by way of absolution, to the dead by way of suffrage." From this authentic definition of the Supreme Legislator of the Church, it is apparent that an indulgence is not a license to commit sin nor a pardon for future sins. Neither is it the remission of the eternal punishment due to sin.
In the commission of every sin a two-fold wound is inflicted upon the soul, first, the stain of guilt, reatus culpae, which consists in turning away from God and the turning towards creatures. If this turning away from God and turning towards creatures is complete, the bond of charity existing between God and the soul is broken, the soul loses sanctifying grace and incurs spiritual death. Such is mortal sin. On the other hand, if our aversion from God is not complete, the soul does not incur this spiritual death. In addition to the guilt of sin, there is also a debt of punishment, reatus poenae. Saint Thomas teaches that because mortal sin consists primarily in the aversion from God and secondarily in the conversion to creatures, and is, therefore, a complete rebellion against the Creator, it deserves eternal punishment. But venial sin, being only a partial aversion from God, deserves only a temporary punishment since the soul still remains in the state of sanctifying grace."
It has always been the teaching of the Church that mortal sins committed after the reception of Baptism may be forgiven only by the Sacrament of Penance, or if this is impossible by an act of perfect contrition with the intention of confessing as soon as possible. Although by this act mortal sin together with the aversion from God and the eternal punishment are remitted, nevertheless, there is still due a debt of temporal punishment, since the conversion to creatures still remains.
Such however, is not the case in the matter of venial sins. The Council of Trent teaches "by these sins we are not excluded from the grace of God, although they may rightly and profitably, and without presumption be declared in confession, yet they may be omitted without guilt, and be expiated by other remedies." The most common of these remedies are the reception of the Holy Eucharist, acts of contrition and the use of the sacramentals.
Since as we have seen, an indulgence is not the remission of sin, the question might be asked how certain formulae of earlier days are to be understood where indulgences are granted a culpa et poena, i.e. from guilt and punishment. Certain theologians: have taught that this phrase a culpa et poena is to be understood in the following manner: the indulgence presupposing the reception of the Sacrament of Penance on the part of the penitent who is thus freed from the guilt of sin, now releases him from the temporal punishment due to sin. It is the accepted opinion of most theologians that this form signifies nothing else than the remission of the temporal punishment due to sin, for the eternal punishment due to sin is always forgiven with the guilt of sin. That this form of granting indulgences did not meet with the approval of the Church is evident from the fact that the Council of Constance in 1417 revoked all indulgences in which this formula occurred.
That the Church has the power of granting indulgences is a matter of faith since this declaration was made by the Council of Trent in the following words: "Since the power of granting indulgences has been given to the Church by Christ, and since the Church from the earliest times has made use of this divinely given power, the holy synod teaches and ordains that the use of indulgences, as most salutary to Christians and as approved by the authority of the councils, shall be retained in the Church, and it further pronounces anathema against those who either declare that indulgences are useless or deny that the Church has the power to grant them." Likewise this prerogative of the Church may be proved from the words of Holy Scripture," "And whatsoever thou shalt loose on earth, it shall be loosed also in heaven." As a consequence of Our Lord's words this power of loosing is not restricted to sins, but extends to any bond which is able to prevent man from attaining his ultimate end. Moreover this power of remitting sins which is in the Church involves the power of conceding indulgences, since a power of this kind ought to be able to remit also the punishment remaining after the guilt has been wiped away.
In order that the Church have this power of granting indulgences two things are necessary and suffice, namely, that the Church have a spiritual treasury from which satisfactions for temporal punishments due to sins may be drawn; secondly, that there be for the faithful the possibility of satisfying for this temporal punishment. In the Bull Unigenitus published by Pope Clement VI, His Holiness has defined that such a treasury exists. in the following words, "Christ shed of His blood not merely a drop, though this would have sufficed, but a copious torrent, thereby laying up an infinite treasury for mankind." In addition there are the works of the Blessed Virgin who was without sin and consequently was not bound by any debt of temporal punishment. To these may be added the sufferings and penances of the saints and martyrs which were far greater than the temporal punishments they incurred. The second condition required that the Church have this power of conceding indulgences is found in the Communion of Saints. By this union, all of the faithful are so intimately joined under one head, Christ, as in a body, that all the good works of the just become as it were the property of each one and accrue to the profit of each.