be considered in two ways.
First, with regard to the species of the act, and thus it is opposed
to truth; as stated (in the body of the article and Q. 110, A. 2).
Secondly, with regard to its cause, from which more frequently though
not always it arises: and thus it proceeds from pride as its inwardly
moving and impelling cause. For when a man is uplifted inwardly by
arrogance, it often results that outwardly he boasts of great things
about himself; though sometimes a man takes to boasting, not from
arrogance, but from some kind of vanity, and delights therein,
because he is a boaster by habit. Hence arrogance, which is an
uplifting of self above oneself, is a kind of pride; yet it is not
the same as boasting, but is very often its cause. For this reason
Gregory reckons boasting among the species of pride. Moreover, the
boaster frequently aims at obtaining glory through his boasting, and
so, according to Gregory, it arises from vainglory considered as its
end.

Reply Obj. 3: Wealth also causes boasting, in two ways. First, as an
occasional cause, inasmuch as a man prides himself on his riches.
Hence (Prov. 8:18) "riches" are significantly described as "proud"
[Douay: 'glorious']. Secondly, as being the end of boasting, since
according to _Ethic._ iv, 7, some boast, not only for the sake of
glory, but also for the sake of gain. Such people invent stories
about themselves, so as to make profit thereby; for instance, they
pretend to be skilled in medicine, wisdom, or divination.
_______________________

SECOND ARTICLE [II-II, Q. 112, Art. 2]

Whether Boasting Is a Mortal Sin?

Objection 1: It seems that boasting is a mortal sin. For it is
written (Prov. 28:25): "He that boasteth, and puffeth himself,
stirreth up quarrels." Now it is a mortal sin to stir up quarrels,
since God hates those that sow discord, according to Prov. 6:19.
Therefore boasting is a mortal sin.

Obj. 2: Further, whatever is forbidden in God's law is a mortal sin.
Now a gloss on Ecclus. 6:2, "Extol not thyself in the thoughts of thy
soul," says: "This is a prohibition of boasting and pride." Therefore
boasting is a mortal sin.

Obj. 3: Further, boasting is a kind of lie. But it is neither an
officious nor a jocose lie. This is evident from the end of lying;
for according to the Philosopher (Ethic. iv, 7), "the boaster
pretends to something greater than he is, sometimes for no further
purpose, sometimes for the sake of glory or honor, sometimes