I recently listened to a CD on anger by a Catholic deacon who is also a psychiatrist, or perhaps a psychologist, I don't recall which now. I found his presentation confusing and, while much was worthwhile, I disagreed with some of the points he made. He never defined his terms well. He seemed to lump all anger under the umbrella of sinful anger. He seemed to define righteous anger (he never used the term) as "indignation." And, in fact, condemned a pro-life pamphlet justifying anger against abortion which, frankly, aroused my indignation. I thought his comments were unjust and off-target and that the pro-life group was describing righteous anger that leads to action against the evil of abortion.
When I think of the murder of unborn children, indignation just doesn't cut it. Is slicing and dicing babies not a cause for anger if anything is? What arouses me to the desire to fight that injustice is hatred of its evil and anger over the murder of the innocent. Yes, anger is exactly what we should experience over such an evil and that anger should spur us to do something about it!