III. Charity obliges us to rejoice at a neighbor's good, and to banish envy, which consists in a feeling of regret at the good of others, inasmuch as it is an obstacle to our own.
According to St. Thomas, a person may grieve at the good of others in four ways:
First, when he apprehends that their advancement will be detrimental to himself or to others; and if the loss sustained be unjust, his regret is not envy, and may be blameless." " It may often happen," says St. Gregory, " that without losing charity, we rejoice at the ruin of an enemy; and that without incurring the guilt of envy, we feel sorrow at his exaltation, when by his downfall we think that others will be justly exalted, and when we fear that by his prosperity many will be unjustly oppressed."
Secondly, when a person grieves not because others have been prosperous, but because he himself has not been equally successful. This grief is not envy, but is, on the contrary, an act of virtue when it regards spiritual goods.
Thirdly, when he regrets the success of others, because he deems them unworthy of it; and this sorrow is not sinful, when he believes that the advantages, dignity, or riches that they have acquired will be injurious to their salvation.
Fourthly, when a person regrets the prosperity of others, because it is an obstacle to his own advancement: this is envy, and should not be entertained. The Wise Man says that the envious imitate the devil, who instigated our first parents to sin, because he was grieved
