pious works, if he persist in carnal
inconstancy impenitent until death.

Reply Obj. 6: One copulation may result in the begetting of a man,
wherefore inordinate copulation, which hinders the good of the future
child, is a mortal sin as to the very genus of the act, and not only
as to the inordinateness of concupiscence. On the other hand, one
meal does not hinder the good of a man's whole life, wherefore the
act of gluttony is not a mortal sin by reason of its genus. It would,
however, be a mortal sin, if a man were knowingly to partake of a
food which would alter the whole condition of his life, as was the
case with Adam.

Nor is it true that fornication is the least of the sins comprised
under lust, for the marriage act that is done out of sensuous
pleasure is a lesser sin.
_______________________

THIRD ARTICLE [II-II, Q. 154, Art. 3]

Whether Fornication Is the Most Grievous of Sins?

Objection 1: It would seem that fornication is the most grievous of
sins. For seemingly a sin is the more grievous according as it
proceeds from a greater sensuous pleasure. Now the greatest sensuous
pleasure is in fornication, for a gloss on 1 Cor. 7:9 says that the
"flame of sensuous pleasure is most fierce in lust." Therefore it
seems that fornication is the gravest of sins.

Obj. 2: Further, a sin is the more grievous that is committed against
a person more closely united to the sinner: thus he sins more
grievously who strikes his father than one who strikes a stranger.
Now according to 1 Cor. 6:18, "He that committeth fornication sinneth
against his own body," which is most intimately connected with a man.
Therefore it seems that fornication is the most grievous of sins.

Obj. 3: Further, the greater a good is, the graver would seem to be
the sin committed against it. Now the sin of fornication is seemingly
opposed to the good of the whole human race, as appears from what was
said in the foregoing Article. It is also against Christ, according
to 1 Cor. 6:15, "Shall I . . . take the members of Christ, and make
them the members of a harlot?" Therefore fornication is the most
grievous of sins.

_On the contrary,_ Gregory says (Moral. xxxiii, 12) that the sins of
the flesh are less grievous than spiritual sins.

_I answer that,_ The gravity of a sin may be measured in two ways,
first with regard to the sin in itself, secondly with regard to some
accident. The gravity of a sin is measured with regard to the sin
itself, b