We show ourselves and others the highest regard and respect when we are honest and "real" with them, while at the same time we keep their humanity in mind. The first keeps us from being duplicitous and manipulative, while the second prevents us from treating others merely as means to our own ends.

Disagreement and conflict is especially best handled in this way. I can sincerely and vigorously debate someone on an issue: however, the second I de-humanize that person in my mind, reducing them merely to a set of ideas, I have probably lost any chance of convincing or persuading them of anything. I have likely alienated them as well. That's bad in business, and it's bad in personal matters as well.