Social justice matters because we-each of us-matter. Unless we learn to co-exist as equals, we will never live optimally. To denigrate any one of us is to demean all of us. Absent the wholesale embrace of social justice, we risk succumbing to human tendencies to stereotype, "otherize," and scapegoat. Those tendencies, left unchecked, lead to horrific ends. When we see ourselves in others, we understand that our shared humanity...