onsequently,
no one is forbidden to behold Christ's body, when once he has
received Christ's sacrament, namely, Baptism: whereas the
non-baptized are not to be allowed even to see this sacrament, as is
clear from Dionysius (Eccl. Hier. vii). But only those are to be
allowed to share in the eating who are united with Christ not merely
sacramentally, but likewise really.

Reply Obj. 5: The fact of a man being unconscious of his sin can come
about in two ways. First of all through his own fault, either because
through ignorance of the law (which ignorance does not excuse him),
he thinks something not to be sinful which is a sin, as for example
if one guilty of fornication were to deem simple fornication not to
be a mortal sin; or because he neglects to examine his conscience,
which is opposed to what the Apostle says (1 Cor. 11:28): "Let a man
prove himself, and so let him eat of that bread, and drink of the
chalice." And in this way nevertheless the sinner who receives
Christ's body commits sin, although unconscious thereof, because the
very ignorance is a sin on his part.

Secondly, it may happen without fault on his part, as, for instance,
when he has sorrowed over his sin, but is not sufficiently contrite:
and in such a case he does not sin in receiving the body of Christ,
because a man cannot know for certain whether he is truly contrite.
It suffices, however, if he find in himself the marks of contrition,
for instance, if he "grieve over past sins," and "propose to avoid
them in the future" [*Cf. Rule of Augustine]. But if he be ignorant
that what he did was a sinful act, through ignorance of the fact,
which excuses, for instance, if a man approach a woman whom he
believed to be his wife whereas she was not, he is not to be called a
sinner on that account; in the same way if he has utterly forgotten
his sin, general contrition suffices for blotting it out, as will be
said hereafter (Suppl., Q. 2, A. 3, ad 2); hence he is no longer to
be called a sinner.
_______________________

FIFTH ARTICLE [III, Q. 80, Art. 5]

Whether to Approach This Sacrament with Consciousness of Sin Is the
Gravest of All Sins?

Objection 1: It seems that to approach this sacrament with
consciousness of sin is the gravest of all sins; because the Apostle
says (1 Cor. 11:27): "Whosoever shall eat this bread, or drink the
chalice of the Lord unworthily, shall be guilty of the body and of
the blood of the Lord": upon which the gloss observ