Mathematically, it is posible to make a relationship between the concepts of goodness and evil and the state of a system. This is how.
Entropy is an index related to the probability of a system to reach a certain state. States of high probabilities are said to have high entropy and vice versa. Entropy is not related to chaos, because chaos or order are in fact states, and entropy is precisely the probability of each one of that states. Moreover, in order to define the entropy of a system, a criteria of state is required.
For example, it can be said that the state ‘biological life’ has a very low entropy. Despite the complexity of this consideration and its physical assessment, this definition can provide a clear relation between order, life, chaos, disorder and the lack of biological existence or death. In fact, for the purpose of this mental experiment, no assessments are required. The only nuance to remark is that order and chaos are not discrete and absolute states, but moreover a continuous variable function.
Then, life is related to an order of the internal subsystems of a system, and chaos, death or disorder are related to the lack of order of all internal subsystems. An additional consideration can be added: goodness can be considered just a synonym of order, and evil, just a synonym of chaos. Just words, nothing concrete. The only logic applied here is relating good with biological life and evil with chaos, which seems coherent with the linguistic concepts of good and evil.
So, here comes the math. If good is a synonym of order, any internal increase of order is good. Any decrease of order is bad, evil. When a wolf kills a rabbit to eat it, the internal order of the wolf increases. The state of life increases its probability, due to the action of feeding is positive for wolves.
The act of killing on predators has not the purpose of destroying preys, causing chaos, or being evil, but just to provide internal order. In simple words, killing a prey is good for the predator. Predators don’t destroy preys, they just feed itselves. Predators don’t act against preys, but only obey its instinct of survival. No living being (and probably no thing on the universe) interacts with others in order to destroy. All living beings interact just to get an internal reduction of entropy. In simple words, all living beings act towards their own existence, not towards the other’s destruction. No system interacts to cause chaos on the environment, for the simple reason that creating chaos risks own existence.
This concept requires to be analyzed: a system that creates chaos risks its own existence. If a system spreads chaos on the environment, the environment becomes unstable, and therefore the very system risks its existence in time.
If there were a pure concept of a system that is able to create and spread chaos, that could be considered an evil system. Pure evil, in consequence, can be the tendency of a system to destroy itself.
Humans behave exactly the same way. A pure evil individual would be the one that acts towards suicide. Any other type of act is not evil, just a positive act for the system. For example, a person who kills a child is not evil. If the person expects to die as a consequence of the murder, that would be evil. But if the person escapes, it is looking for life, and therefore it has murdered only to get some internal satisfaction.
This must sound crazy, and difficult to understand, but it is just a logical consequence: a person that harms another and wants to continue living is just looking for internal satisfaction (order, goodness). Killing another person, therefore, is not evil. It just provides a dose of internal goodness. In general, any act against others has not the purpose of harming others, but instead, to provide a personal benefit, satisfaction, pleasure, etc. Which is comparable to a predator killing a prey. Both individuals act only for internal pleasure.
Therefore, what is evil? Evil is the real destruction. A suicidal is evil. But humans, as a part of this nature, as living entities, as beings, as systems, have not embedded the capability of generating chaos. Instead, humans are able to generate chaos only… by ignorance. Yes. By lack of knowledge.
In fact, a person who harms the planet is just destroying it because it has not the knowledge of the damage it is causing. A person who really understands the damage it is causing instinctively stops all destruction. It is just instinct. But humans act towards destruction only by ignorance.
A person who has the empathy to understand how a victim suffers a torture, is unable to torture. Only people lacking of empty is able to kill, torture, harm, damage, others or the planet. Therefore, the main human problem in relation to the ecological disbalance is just the lack of knowledge.
Moreover, a person who does harm by ignorance, would be exactly like another person who makes the same act intentionally. In consequence, ignorants can be as evil as bad guys.