A person may hold that evil is a literal presence, a real energy. This is substantial evil.
Another person may dispute this and state that evil is a mere deficiency, something failing to be as good as it should be. They say the only power is good or neutral and evil is just the misuse of these things. This is parasitical evil. It was popularised by Augustine of Hippo.
Belief that there is evil in human nature is a barrier to understanding the "evil" person and thus throwing them to the wolves and turning them into worse wolves than they are now! Evil is that which needs total opposition for it is inexcusable and intense dislike of it is the only valid emotional response. Religion says that we have free will to cause evil for God is only good and has nothing to do with it.
WHY THE WORD EVIL BLOCKS LISTENING AND UNDERSTANDING
When you ask people to define evil you get melodramatic emotive gibberish. You get fantasies and word salads. For example, Christianity says that evil is not substantial but is just good in the wrong place and time. It says God cannot make evil and he makes only good. That implies that evil is simply a word for what falls short of the good it should be. So evil becomes a mere absence of a good that is missing.
Defining it as harm is a problem for the dentist has to harm you to do good. Defining it as forbidden is too much about rules as if suffering does not matter. Defining it as something that should be totally opposed and hated is telling people how to feel. And we still are not told why it should be so repulsive.
Implicitly and explicitly many say evil is impossible to define and that definitions only give some light but that ultimately evil is a mystery. To say you cannot define evil exactly or at all but you know it when you see it, is too subjective. People do not necessarily know evil when they see it. And too often the evil is only seen when it suits them. Also the mystery talk makes evil out to be magical or supernatural. If it may use people of this world and not be of this world itself then it follows that if reach an understanding with a person as to why they did an evil you never know if you really understood. Understanding would need to be a miracle.
If evil is a puzzle then it may take the evil in you to know evil anywhere else. It may just be the case. What could you expect when the definitions are so foggy?
If so then in other words, it takes an evil person to see the evil in others. It definitely does if the evil is not really there or there is no real reason to think it is there. Christianity is definitely trying to see evil. To see evil in something as flimsy and flat as "murder is merely the making of a life absent where it should exist" is desperation.
I would add that if you stand apart from yourself to look at the evil inside you, a paradox arises. You have to rouse evil to spot the evil. It is the same with yourself as with another person.
No person who sees what they say is evil agrees exactly on how and why it was evil. Evil is very much in the eye of the beholder. That fault is in human perception. That is not down to the evil.
Evil hides itself in good and lies that it is good or it will be worth it eventually when all the results are weighed up. And some things have both a level playing field with good and bad. That makes knowing what exactly it is up to and what is happening very hard and impossible in many cases and that fogging is down to the evil. Evil is a fog and a lie.
Evil resists diagnosis meaning attempts to deal with it will empower it in some ways for a time for they are imprecise. Needless to say trying to understand the evil person is out.
IF EVIL IS SUBSTANTIAL THEN THERE IS NO PLACE FOR UNDERSTANDING
Those who want us to believe in evil, say there is room for respecting and listening to and understanding the evil person.
They argue that the reason is that good reasons are involved though they do not excuse. They say that the reason is that evil is not seen as and is not substantial. The fact remains though that seeing something as poison, deceptive, mysterious and malevolent stops the conversation. It does not matter what it is.
To say that the simple act of seeing evil as substantial dehumanises the person doing evil is a distraction and a lie. What it is, is not the point.
Mary has a terrible pain in her back. She may really have an injury. Or she may need to have a pain and is subconsciously making it and there is nothing wrong with her. Either way she needs help and attention. It does not matter if the back pain is real or not. And the same with evil.
When people gleefully cause grave suffering, we refer to it as an act of pure evil. Pure evil. We want to believe this deed is purely evil and nothing else. More importantly we need to believe it. You cannot define exactly what you mean by pure evil or what it is. So it is expressing a feeling. You think you sense that the deed is wholly evil. I suspect those people are calling evil substantial or as good as. It depends on how they react to it.
The victims try to keep thinking about the terrible thing done to them in order to look for reasons or answers as to why somebody would hurt them. Thus the pain directly caused has indirect consequences too. It is like the person thinks that the more he or she relives the pain and the event the bigger the chance of a breakthrough where the light of understanding and the help it brings comes in.
The deed causes suffering to those not directly affected by the atrocity. It is not just victims who are the victims.
The more you try to understand all the evil the more angry and frustrated you become because there is no way to understand it and evil is not about being understood. It must be noted that this is because evil is destruction - even if it is not really complete evil it is complete evil to us. Philosophers can argue about if evil is a lack of good ie a non-power, or a power. We see it as substantial evil and we need to.
If you say a deed was complete evil, you are saying there is nothing there to understand. Also, if it is substantial there is nothing there to understand either. You cannot interview and talk to evil. But this is rendered into unimportance by the fact that you need to see the act as substantial evil even if it is not really. Understanding is about looking at the reasons why the person did the things they did but the fact remains that these were not reasons but excuses. What place is there for real understanding? None.
If evil is useless and only about destroying then it is stupid to ask why it happened for by definition it would be happening ultimately for no reason. Thinking about the evil to try and understand it is futile. Calling something evil is not about explaining why it happened but that it happened.
Does it make sense to say that a person who commits an atrocity is insane and thus not evil but his action is truly substantial evil? No. It would be as natural as an earthquake then and nobody resents an earthquake as substantial evil. To call the act substantial evil is to blame the doer of the act.
Strictly speaking to try to understand an evil act is just a way of saying you are trying to understand the evil person. There is no such thing as merely understanding an action. It is people you have to understand.
To call something evil is to say it is the complete opposite of what you would do. So it's too polarised for any real understanding. It is to say that the evil person is the opposite of the kind of person you are. Thus you divide yourself from the evil or supposedly evil person. If it is true that the “evil” person needs understanding and the causes of evil deeds are more complex than we will ever know then we are going to their level by excluding them and by implication treating them as less than human.
Religion's efforts to understand evil only feed evil and it cannot complain if members get angry enough to resort to war against the perceived wicked.
So if you cannot try to understand evil then what do you do? You cannot just put the evil out of your mind after it happens for you need to relive it and "repeat" it long enough to grasp how evil it was. You need to understand the evil done by a person before you can understand anything about the person. It would be monstrous to start living as if nothing happened seconds after somebody fires a gun at you or rapes you. Nevertheless in time you must try to be not a victim but a survivor or even a coping person. The worry with that suggestion is it says, "Okay you have hurt yourself by reliving what happened so you are as bad as the person who hurt you. You cannot judge." It blames the victim. We may have to live with that for moving on is essential.
This idea is resigning yourself to the fact that evil happens and there is nothing you can do to stop people being evil but all you can do is stop it winning.
If evil is substantial or at least something that is not but acts like it is, then is there any point in trying to understand why a person did something evil?
No. If the evil made its home in them and manipulated them it will make it look even to them like they were to blame for the evil though they were not. Or maybe not fully to blame. You would never know where the person starts or finishes. Trying to understand them is like trying to understand why somebody has skin. Evil wants you to blame the person's psychology to protect itself and its presence.
Religion wants to preserve the need for understanding for that is a prelude to and part of forgiving. Without understanding there is no forgiving.
M Scott Peck pointed out that witnessing and studying evil will do something to your soul. Some kind of damage sets in. Evil infects those who behold it. I would say that if the evil is imagined or you think you see it, the same thing will happen. The evil you see in others is too much about the evil in you. Evil depends on deception and that is one reason why it can have surprising capturing effect on the witness. That aside it seems to appeal to the bad side of the person. It corrupts and threatens further corruption.
Wily Peck did not admit though that understanding why a person did evil means you are letting them give you reasons and excuses for being evil yourself. Psychologists say that understanding is not condoning. True. But it is condoning an evil person helping another to understand them and the person can only understand them if they have evil within themselves. If evil has a contagious influence that cannot be fully explained as everybody says, then listening to the evil person even when your intention is to help and understand is dangerous. Loving the sinner and hating the sin would be impossible and also irresponsible. It would be itself evil.
The end result is a limbo. The evil person needs understanding and cannot be granted it.
FINALLY
How do we talk about evil?
Descriptive evil (e.g., “he murdered six people”). If evil is substantial then the person is possessed by it or is literally part of it and must be eliminated immediately.
Moral evil (e.g., “that act was unjustifiable”). Again, if evil is substantial then the person is possessed by it or is literally part of it and must be eliminated immediately.
Mythic evil (e.g., “he was the embodiment of evil”). Evil here is treated as substantial or as good as - meaning it makes little difference what side you take.
Defensive evil (e.g., “we had to fight evil to protect ourselves”). If evil is substantial, it will be present even as we use it to fight for our lives but it will bite back. It will come for us.
The first reponse to any of those is fear not understanding. It is also urgency before patience.
All say that evil is a threat and deserves fear and needs counteracting. It hides what it is doing. Then the persons engaging in it do the same thing. Plus evil needs a network and not all parts fit together. Not all understand correctly what they are supposed to be doing for it/ Therefore understanding exactly what is happening will always elude. You make assumptions and hope for the best and yet you are told to listen and not make assumptions! All that fear and mystery prevents the person being understood. If you cannot understand a person who does harm how you can you understand them if they do good? The reality is that people are selective in what evil they are against and why and in who is dealt with. No wonder!
Suspecting evil to be substantial adds on to the problems. As does treating it as substantial.
And affirming it as substantial reinforces the problems.
You compound that by saying that it is more than substantial but magical or supernatural. Also, if it is neither magical or supernatural or nothing like that then you lose focus in handling it for you have the wrong idea about it.
You have less confidence in battling evil if you see it in those ways.
Also, no matter what evil is, if the remedy is a sacrament or a spell or a prayer or something else supernatural or paranormal that implies that this matters more than understanding the evildoer. Assuming everybody needs to be heard and understood and then helped, to put magic first would be completely unacceptable.