This is rather long, but I thought some actual Epicurean teachings might be a change. (I have split it into three postings for the sake of digestability).
Phildemus was an Epicurean who wrote, among other things, about anger. There was a huge contrast between the Stoic and Epicurean schools. Stoics idealized apathy (or lack of emotion) and saw all anger as an evil that had to be repressed. Epicureans teach that it’s a bad idea to suppress human nature. Anger is seen as completely natural. Philosophy, the ancient Epicureans thought, would lack compassion if it didn’t allow us to experience “natural anger”.
Diagnosing an ailment of the soul
Epicurean therapeutic process has much in common with medicine, and is inspired by Hippocratic models: symptoms, diagnosis, therapies and cures. The scroll begins with symptoms of anger, which are physical, psychological and social.
Among the physical symptoms, we find that the face reddens and the heart quickens. The psychological ones include how one begins to plot revenge and takes delight in imagining that something bad happens to the enemy. Such anger is compared sometimes with dementia or madness, which can also be applied to furious people.
The angry person says reckless things that are impossible to take back, sometimes in the presence of bosses or powerful people, and this can cause physical danger, legal problems, and rejection by family and friends. It can destroy families and relationships with loved ones, and can even destroy a country.
Philodemus mentions the dynamics that arise whenever there are relationships based on exploitation and domination, such as slavery. In these cases, the animosities that may arise are huge. These dynamics are still seen between workers and employers today.
Rational and natural anger
The first type of anger that Philodemus discusses is natural anger, which does not need treatment other than the hedonic calculus, i.e. the long-term measurement of gains and losses with the goal of ensuring net pleasure. The purpose of the hedonic calculus is not to find the most pleasant way to get revenge, but to ensure the highest long-term stable peace of mind, which opens the door to creative techniques of non-violent conflict resolution.
The Stoics questioned whether anger was natural. But Philodemus said that anger was often unavoidable and compared the debt we owe to people who have hurt us voluntarily with the debt of gratitude we owe to people who have benefited us. Anger can be natural when other people voluntarily cause us harm. A good rule to determine whether anger is natural, is to measure whether the damage has the potential to destroy life or take away our safety, the health of the body or happiness.
There are three possible reactions to loss or damage we have sustained. The first is indifference (somewhat unrealistic). The second is hostility (natural). The third is to express friendship toward our abusers, which would be stupid.
The recognition of natural anger also important in understanding the potential dangers of other ethical philosophies such as Stoicism (which idealizes unqualified resignation as a virtue and teaches to repress the natural and healthy emotions, and Christianity (which says we should turn the other cheek). These ethical philosophies perpetuate social injustice that could be resolved through non-violent conflict resolution methods like the boycott, exposing our foes to shame and public scrutiny, and other tactics. Sometimes the remedies for social injustice have been somewhat violent, (such as the American civil rights movement in the case of Martin Luther King Jr).
Many other indignant voices (like current Black Lives Matter and Occupy) can be looked upon as rational, ennobling causes that channel anger and sometimes result in social change for the better. Philodemus spoke of these when he spoke of “virtuous dispositions” underlying our natural and rational anger. No social progress can happen if we don’t allow rational, natural anger to find expression and change the world.
Anger can be a good as long as it is brief and has its origin in a virtuous cause. Even wise and virtuous men experience natural anger, which is moderate, rational, calculated.
(Adapted from the books “Tending the Epicurean Garden”, “Les Epicuriens” and from Elizabeth Asmis’ commentary in her article “The Necessity of Anger in Philodemus’ On Anger” in “Epicurus and the Epicurean Tradition”)
I believe it was rational anger that Jesus expressed when he saw the temple in Jerusalem being used as a marketplace to rip off those who wanted to practice the religion. So Christianity seems to have some provision for it, though telling people to turn the other cheek and to love their enemies are unrealistic commandments no one can be expected to follow.
Though on the whole I agree with Epicurus on the issue of anger, I can see where the Stoics are coming from. At the very least, anger is an emotion to be avoided. It can obviously lead people to commit wrongdoing, even if they are understandably angry over an injustice. You mention Black Lives Matter; while the organisation itself is a peaceful one, many people loosely associated with it have committed acts of violence. Conservative commentators have argued that riots in cities like Ferguson and Baltimore, as well as the killing of police officers, have been inspired by the rhetoric and arguments of BLM. Now unless someone officially recognised by BLM has endorsed violence, you cannot blame BLM for violence in the same way as you cannot blame anti abortion activists for directly inciting violence against abortion clinics. A recognition of injustice is important, but its equally important to be a society of individual responsibility. If a person is violent out of an understandable anger, they and they alone are responsible. But if the conservative commentators are right, and BLM anger over police brutality inevitably leads to violence against cops, then the Stoics are right: it would be better not to be angry in the first place.