ultery, murder, and theft
are sins of deed. Therefore backbiting is not graver than the other
sins committed against one's neighbor.

_I answer that,_ The essential gravity of sins committed against
one's neighbor must be weighed by the injury they inflict on him,
since it is thence that they derive their sinful nature. Now the
greater the good taken away, the greater the injury. And while man's
good is threefold, namely the good of his soul, the good of his body,
and the good of external things; the good of the soul, which is the
greatest of all, cannot be taken from him by another save as an
occasional cause, for instance by an evil persuasion, which does not
induce necessity. On the other hand the two latter goods, viz. of the
body and of external things, can be taken away by violence. Since,
however, the goods of the body excel the goods of external things,
those sins which injure a man's body are more grievous than those
which injure his external things. Consequently, among other sins
committed against one's neighbor, murder is the most grievous, since
it deprives man of the life which he already possesses: after this
comes adultery, which is contrary to the right order of human
generation, whereby man enters upon life. In the last place come
external goods, among which a man's good name takes precedence of
wealth because it is more akin to spiritual goods, wherefore it is
written (Prov. 22:1): "A good name is better than great riches."
Therefore backbiting according to its genus is a more grievous sin
than theft, but is less grievous than murder or adultery.
Nevertheless the order may differ by reason of aggravating or
extenuating circumstances.

The accidental gravity of a sin is to be considered in relation to
the sinner, who sins more grievously, if he sins deliberately than if
he sins through weakness or carelessness. In this respect sins of
word have a certain levity, in so far as they are apt to occur
through a slip of the tongue, and without much forethought.

Reply Obj. 1: Those who detract Christ by hindering the faith of His
members, disparage His Godhead, which is the foundation of our faith.
Wherefore this is not simple backbiting but blasphemy.

Reply Obj. 2: Reviling is a more grievous sin than backbiting, in as
much as it implies greater contempt of one's neighbor: even as
robbery is a graver sin than theft, as stated above (Q. 66, A. 9).
Yet reviling is not a more grievous sin than adultery. F