Envy is often mistaken for anger at injustice, because both can issue in hatred. But the hatred that issues from a desire for justice is righteous, whereas the hatred that issues from envy is wicked. How can we know the difference? One telltale sign is the object of one’s hatred. Is it what a person does? Or the person himself? Aquinas writes:
It is lawful to hate the sin in one's brother, and whatever pertains to the defect of Divine justice, but we cannot hate our brother's nature and grace without sin. Now it is part of our love for our brother that we hate the fault and the lack of good in him, since desire for another’s good is equivalent to hatred of his evil. Consequently the hatred of one's brother, if we consider it simply, is always sinful. (Summa theologiaeII-II.34.3)
Morally legitimate hatred is always grounded in love. One loves both justice and one’s brethren, and thus hates and seeks to correct any injustice that harms both the social order and the brother committing the injustice. If one hates one’s brother himself, the hatred is evil.
Now, it is not merely human beings in the abstract to whom we owe love. The virtue of piety requires that we have a special love for certain others. Aquinas writes:
Man becomes a debtor to other men in various ways, according to their various excellence and the various benefits received from them. On both counts God holds first place, for He is supremely excellent, and is for us the first principle of being and government. On the second place, the principles of our being and government are our parents and our country, that have given us birth and nourishment. Consequently man is debtor chiefly to his parents and his country, after God. Wherefore just as it belongs to religion to give worship to God, so does it belong to piety, in the second place, to give worship to one's parents and one's country.
The worship due to our parents includes the worship given to all our kindred, since our kinsfolk are those who descend from the same parents… The worship given to our country includes homage to all our fellow-citizens and to all the friends of our country. Therefore piety extends chiefly to these. (Summa theologiaeII-II.101.1)
(Obviously, Aquinas is using “worship” here in a broad and archaic sense that entails merely the showing of due respect. He is not talking about “worshipping” parents or country in the way that we worship God, but rather in the sense of showing respect for them.)
So, just as hatred of injustice is legitimate when we see injustice in our brother, so too can it be legitimate when we see it in our parents, family, fellow citizens, or country. But hatred of parents, family, fellow citizens, or country themselves(and, even more, of God) is evil. Indeed, these kinds of hatreds are especiallyevil, given the special duty of piety we owe toward these others. These hatreds are themselves further instances of injustice, as well as sins against charity.
Of course, hatred of a person, or of parents, country, etc. can be the byproduct of something other than envy, such as an overreaction to injustice. But that is not usually the case, and even when it is, such an overreaction can morph into envy. Aquinas again:
Hatred may arise both from anger and from envy. However it arises more directly from envy, which looks upon the very good of our neighbor as displeasing and therefore hateful, whereas hatred arises from anger by way of increase. For at first, through anger, we desire our neighbor's evil according to a certain measure, that is in so far as that evil has the aspect of vengeance: but afterwards, through the continuance of anger, man goes so far as absolutely to desire his neighbor's evil, which desire is part of hatred. (Summa theologiaeII-II.34.6)
In other words, even when anger starts out as a legitimate desire to punish injustice (which is what Aquinas means by “vengeance” – which, as he uses that term, is a good thing) it can, if the anger gets out of control, mutate into a desire to harm the person, to act contrary to what is good for him. That is hatred of a wicked kind, and it bears the chief mark of envy. Thus, as Aquinas writes in the same place, “envy of our neighbor is the mother of hatred of our neighbor.”
What is envy? People often confuse it with jealousy, the desire to preserve what one has or to acquire for oneself a good of the kind that another has. Jealousy in that sense is not wrong. If Bob is worried about losing his job or his wife to Fred (where Fred is trying to take these things from him), there is no sin in that. Far from it. Or, if Fred has a wife and a job and Bob, having neither, wishes he had a wife and a job too, there is no sin in that either, and in particular no envy. Envy would be present only if Bob wants Fred not to have these things either, because Fred’s having them is perceived as an affront to Bob’s self-respect.
As Aquinas says, with envy, “another's good [is] reckoned as being one's own evil, in so far as it conduces to the lessening of one's own good name or excellence” (Summa TheologiaeII-II.36.1). The envious person ties his own self-respect to taking away from others the good that the envious person himself does not have. Hence, unlike legitimate anger at injustice, which abates when the unjust person shows contrition, envy is not satisfied with anything but the destruction of the person who is its object. “The envious have no pity” (II-II.36.3).
Envy is a capital sin (Summa TheologiaeII-II.36.4). That is to say, it tends to have as a natural byproduct various other specific sins. First, envy seeks to defameanother, to lower his reputation in other people’s eyes. Second, envy takes joy in the harm thereby suffered by the person who is its object (or takes sorrow in whatever goodthe person in question still possesses). Third, and again, there is hatred of the person himself (and not just hatred of what he does or of the fact that he unjustly has a certain good).
Here is how we know, then, whether we are dealing with righteous anger or envy: Righteous anger is directed primarily at actions, envy is directed primarily at people. Righteous anger can be abated, envy is pitiless. Righteous anger seeks to restore the right order of things, envy seeks to tear down, especially by defamation. Righteous anger evinces love of one’s brother, parents, fellow citizens, country, or God, whereas envy evinces hatred of one or more of these. Righteous anger can be motivated by charity and piety, but envy is contrary to these virtues.
It is righteous anger we see expressed in grand documents like Frederick Douglass’s “What to a Slave is the Fourth of July?,” which attacks the injustice of slavery, and Martin Luther King, Jr.’s “Letter from Birmingham Jail,” which attacks the injustice of segregation. Douglass and King are very hard on the people they are criticizing, and rightly so. But they evince no hatred at all for the people themselves, nor for their country. Rather, they call on their countrymen consistently to apply ideals they all share, namely those of the Declaration and Constitution. They seek, not to harm anyone, but rather to secure justice for those who are being harmed. They deliver stern and well-deserved moral criticism, but criticism that is magnanimous, appeals to reason, and is aimed at restoring fellowship with the people they are criticizing.
Some of what is going on around us today is also motivated by righteous anger at injustice. But some of it is clearly motivated by envy and its daughters, like tares among the wheat. The “cancel culture” that aims to destroy reputations and render people unemployable, the destruction of the property and businesses of people who had nothing to do with the injustice protested against, the push to remove police protection from everyone, the insistence on defaming one’s countryand one’s fellow citizens as rotten to the core, the cruel refusal of any forgiveness, the relentless resort to intimidationrather than rational argumentation– all of that evinces hatred for persons of the kind that is typical of envy. It involves grave sins against charity and piety. It merely adds injustice to injustice.