> That any person esteem his own good or excellence to be worthy of praise is not in itself sinful; nor, in like manner, is it sinful that we should desire to see our good works approved of men. "Let your light shine before men, that they may see your good works" (Matthew 5:16). Hence the desire of glory is not essentially vicious.
> But a vain, or perverse desire for renown, which is called vainglory, is wrong; desire of glory becomes perverse,
> when one seeks renown because of something not really worthy;
> when one seeks the esteem of those whose judgment is undiscriminating;
> when one desires glory before men without subordinating it to righteousness.
> Vainglory may become a deadly sin, if one seek the esteem of men for something that is incompatible with the reverence due to God; or when the thing for which one desires to be esteemed is preferred in one's affections before God; or again, when the judgment of men is sought in preference to the judgment of God, as was the case with the Pharisees, who "loved the glory of men more than the glory of God" (John 12:43).
> The term "vainglory" denotes not alone the sinful act, but also the vicious habit or tendency engendered by a repetition of such acts. This habit is ranked among the capital sins, or, more properly vices, because it is prolific of other sins, viz., disobedience, boastfulness, hypocrisy, contentiousness, discord, and a presumptuous love of pernicious novelties in moral and religious doctrine.
via Catholic Encyclopedia on "Glory": https://www.newadvent.org/cathen/06585a.htm
Aquinas On The Topic: https://www.newadvent.org/summa/3132.htm
