I write in fictional genres that classically lend themselves to a very old school ‘black vs. white’ mentality. The truth is, though, that is boring and unrealistic. It’s not that I don’t see morality and ethics as realistic, it is simply that the human mind doesn’t usually work in absolutes. Even people we would consider to be saintly are not pure white in motivation and action and even the most vicious murderer is often found to have strangely positive points in their personality. The human psyche is far too complex for such absolute moral stances.
In fact, it could be argued that the best conflicts in any piece, no matter how action-packed, comes from the inner turmoil of a good person faced with decisions with no clear positive outcome. The classic ‘choosing the lesser of two evils’ situation can not only make for great drama, but tell more about a character’s mental state and moral compass than pages of ‘telling’ and pontificating. The key, I would say, is to make sure such choice points themselves are not contrived or unrealistic. If it all happens in the flow of the story, it will make for a dramatic and defining character moment.
At the end of the day, it’s the oft-repeated advice to make every hero have flaws and to make every villain have positive points. I think the truth is a bit more nuanced though. I think it could be valid to have a character that truly is so evil as to be irredeemable, but there must be a process to make a person that way. That process has to come out, and in that process you can make a, for instance, heartless serial killer with no good qualities be shown to have once had them. To show how that morality was purged by a spiraling series of no-win choices, the influence of other darker figures, and/or the occasional whim of fate could also be a fascinating addition to the story. Much like you can show a protagonist’s rise through dramatic struggle, you can show the moral fall of an antagonist in the same way.
Maybe what I’m ultimately pontificating about is the simple act of not making characters faceless cutouts representing the archetype you need to fulfill your plot. Archetypes aren’t by their nature bad; in fact, they represent vital tools in the writer’s bag. It is the blank archetypes that can weaken an otherwise fantastic tale until it crumbles, unable to be supported by a base of cardboard cutouts. Remember, for most types of stories, the characters create and support the plot, not the other way around.