Budziszewski says that, from a traditional Christian perspective, the problems of politics are attributable to sin, to the fact that humans are unavoidably susceptible to passions that deflect them from virtue to satisfy mere appetite. We inherently know right conduct, so conscience gnaws at us when we do wrong. We try appeasing it by rationalizing, and it is in the chapters describing the rationalizations, the "moral errors," of communitarians, liberals, conservatives, and abortion and euthanasia advocates that this methodical, accessible, and absorbing little treatise proves most practical.