Justifying evil acts
Overview
Humans often create justifications for evil behavior, either to themselves to alleviate guilt of the act, or to others to convince them the behavior was not evil.
Self justification
Is a common coping mechanism people have to let go of guilt associated with their behavior, for example parents feeding their children junk food, addicts finding reasons for their actions, or people whose livelihood comes from a source they know does evil clutching to reasons why the source is misunderstood or via complex explanations actually doing good.
This self justification can manifest at larger community levels, for example genocide or destructive cultural norms passed down to future generations.
Plausible justification
People in positions of power who act evil often know what they are doing and why, but in order to maintain their position need to convince enough people to not stand up against them by spinning the actions as necessary or positive in some way.
As long as enough people accept the reasoning as plausible enough to not reject those in power the evil act is often disregarded without consequence.
Willful ignorance
It is common for the above two situations to support each other, a population will support evil people who they see as giving them material gain, willfully believing untrue moral arguments to allow evil actions they believe will improve their lives.