What is peace? It’s the absence of violence, certainly, but it’s also much more. St. Augustine called it “the tranquility of order,” which is certainly an important aspect of peace. Peace is experienced personally and communally. When we’re at peace, we’re not filled with anxiety; our homes are not filled with loud arguments and discord; our neighborhoods and cities are safe and well-ordered, not threatening or chaotic; and nations, races and peoples live together in harmony and mutual respect without...