A. About Mortal Sin

9. One must say that someone can be understood to be in mortal sin in three ways: first actually, because namely he is now sinning mortally in an exterior or interior act; second because, after a past mortal sin that he does not recall, he has not repented nor does repent; third because, if he has repented or does repent of the past sin, yet he has not confessed nor been absolved in the Church.

1. About him who is Actually in Mortal Sin

10. About the first I say that he sins mortally, because he simply eats unworthily.

2. About him who has not Repented of a Past Mortal Sin

11. About the second I say that if his negligence is heavy and gross, because of which he does not recall his sin, he is not excused from sin, though he sins less than the first. The point is plain from I Corinthians 11.28, “Let a man,” he says, “prove himself etc.,” for he is bound to examine himself, with the diligence possible for our weakness, before he receives communion.

12. But if his negligence is not gross, as that sufficient examination has been done and no sin occurs to him about which he was not or is not contrite and has not confessed already, he does not sin by receiving communion, though perhaps something lies hidden or fallen into oblivion.

13. The proof is:

First that if, after such examination, he were to die contrite and confessed, he would be saved; but no greater examination is required for receiving communion than for dying in peace.

Second because otherwise anyone at all would be exposing himself to danger in receiving communion; for Psalm 18.13 says, “Who understands his sins?” and Ecclesiastes 9.1, “A man knows not whether he is worthy of love or hate.” Therefore, if it were necessary for someone who receives communion to be in a state of charity, anyone at all would expose himself to danger in receiving communion, since he does not know whether he would be sinning in doing that act.

The third proof is that then the sacrament would not be a sacrament for the wayfarer, since such certitude [sc. knowing one is in a state of grace or charity] does not belong to a wayfarer.

14. For this reason I say that when diligent examination has been done according to the possibility of our weakness, and when contrition has preceded, and confession has been made that, as it seems to man, is sufficient, then he does not sin if he then receives communion. On the contrary, if any sins remain hidden, they are remitted by the sacrament.

3. About him who has Repented but has not Confessed

15. About the third I say that if an opportunity to confess arises, he is bound to confess before he receives communion. The reason is that he must be reconciled not only to God but to the Church, so that he may receive worthily the sacrament of the unity of the Church.

16. But if an opportunity to confess does not arise, and if he can without scandal avoid receiving communion, he is bound not to receive but to wait for confession, for the same reason as said just now [n.15].

17. But if scandal may arise unless he at once receive communion, as if he has put on vestments and, after doing so, he becomes conscious of a mortal sin which he has not otherwise confessed and he does not have a suitable confessor to hand then, with contrition and the will to confess at an opportune time, he can, so as to avoid scandal, celebrate [mass].

18. And likewise as concerns another about to receive communion who is not a celebrant (as when the custom in some religious community or college or church is that all non-priests receive communion), if the case is alike, namely if, when he must receive communion, he does not then have a suitable confessor, he can then receive communion without having confessed. Nor must one say that he is sinning mortally or transgressing the precept in order to avoid scandal, because no precept excludes him from this act in this case. For putting off the confession in act that he then hass in his affection does not prevent him from being a member of the Church militant suitable for the acts in which the members communicate; and he is bound to avoid scandal to a neighbor.