When we look at others as less than human, we cease to be human ourselves.
Again you have penned a thoughtful and thought-provoking essay. It is true, as you say, that each of us carries the choice and the responsibility for what sort of spirit we carry. Just about all of us muddle along somewhere in the middle, I think, showing great compassion and love some of the time and less nice characteristics at other times. One lesson that has been driven home to me time and time again is that when I let the less-nice side have its way, I may realize some short-term goal thereby, but I feel like crap anyway. Anticipating this in advance can help the nicer side gain traction before I have acted. For example, if someone says something that stings, and my clever brain thinks of a "perfect" retort to wound back with, often all that's necessary is to hold back that thought for a few seconds and instead say something which neither yields the point of disagreement nor ratchets up emotion. "I can see that we're both passionate on the subject, and I definitely share your concerns about addressing X," for example. As an added bonus, if my goal is to convince someone that his views are misguided, a non-confrontational approach works much better than insults.
Alexandr Solzhenitsyn put the challenge this way: “If only it were all so simple! If only there were evil people somewhere insidiously committing evil deeds, and it were necessary only to separate them from the rest of us and destroy them. But the line dividing good and evil cuts through the heart of every human being.” It's hard to look within and find evil in our own heart, but it's there, and it must be understood if it is ever to be conquered.
Looking forward to your next essay.