This from Thomas Aquinas
"Article 1: Whether it is sufficient for someone to confess by writing, or is it necessary for him to confess by spoken word?
On the first we proceed as follows: it seems that it is sufficient for someone to confess in writing. For confession is required for the manifestation of a sin, but a sin can be manifested in writing as well as by spoken word. Therefore, it suffices if he confesses in writing.
But to the contrary: in Romans 10:10 it is said, “Confession is made orally for salvation.”
I answer: it must be said that confession is part of a sacrament. So just as in baptism something is required on the minister’s part, namely that he cleanse and speak the words, and something on the part of the one submitting to the sacrament, namely that he intend to and be cleansed, so in the sacrament of penance it is required on the priest’s part that he absolve under some form of words, on he penitent’s part it is required that he subject himself to the keys of the Church, manifesting his sins through confession. Therefore, it is essential to the sacrament that he manifest his sins, and no one may dispense from this as neither may anyone dispense from baptism. But it is not essential to the sacrament that the manifestation be made by spoken word, otherwise no one could receive the effect of this sacrament in any case of necessity except by confessing orally, which is clearly false, for it is sufficient for mutes or for anyone who cannot confess orally to confess by writing or gestures. However, in no case of necessity can anyone be baptized except by water, because water is essential to the sacrament.
But from the Church’s decree a man who can is bound to confess by spoken word, not only because the one confessing orally blushes more in confessing so that he who sins orally is cleansed orally, but also because in all the sacraments that whose use is more common is always accepted. So in the sacramental cleansing of baptism water, which men more commonly use to wash with, is accepted, and in the Eucharist bread, which is a rather common food, and so also in the manifestation of sins it is fitting to use spoken words by which men are more commonly and with more clarity accustomed to signify their concepts.
And in this sacrament a character is not imprinted, but grace for the remission of sin alone is conferred, which no one obtains by sinning. However, he who ignores the Church’s degrees sins; so in baptism he who preserves what is essential to the sacrament while overlooking the laws of the Church obtains the character of the sacrament but here, however, nothing follows.
However, the reasons which are introduced for both sides are not very compelling. For manifestation of sins cannot be so expressly done in writing as in spoken words, nor is what is said in Confession is made orally for salvation” meant with regard to the confession of sins, but rather with regard to the confession of faith."
