As our country is engulfed in the flames of discord, our task is more than merely reporting on events, calling for an end to racism, or making emotional appeals to unity. As Thomas Aquinas reminds us, wrongdoing follows when emotions disobey reason’s commands. When our passions fetter reason and make it their slave, we cannot see how others are using us as pawns in an ideological game.

Against the reign of passions, reason acknowledges two principles—both included by Aquinas as a second set of the principles of practical reason: 1) The Golden Rule (“Do unto others as you would have them do to you”); and 2) Do not answer injury with injury.

Yet it is so much easier to let appetites run wild, and allow injustice and violence to masquerade as justice and righteousness. What we see in many cities today—the looting, burning, assault, and killing—is what we get when we misunderstand justice and become instruments in the hands of ideologues whose task is to inflame and destroy. Their understanding of human advancement depends on a dialectical view of history—that the only way to advance is to burn down the present order. What can be better for ideologues than...