Because Chesterton’s topic is the way in which Christian ideas have often received unexpected vindication in the human effort to make sense of life, his discussion touches on various Christian themes. Some of these include the Trinity; such virtues as courage, modesty, and charity; the certain wrongness of suicide, in connection with which Chesterton first recognized the concurrence of his thoughts with Christianity; and the possible rightness of celibacy, which he claims not fully to understand.
The discussion of capitalism and wealth in the latter part of the book continues the traditional Christian debate about the theological significance of poverty and riches. Chesterton argues (in chapter 7, “The Eternal Revolution”) that only the Christian doctrine of Original Sin provides a logical basis for the defense of democracy against the rule of a wealthy elite. The ideas of Original Sin and the Fall play a central role throughout his reflections on modern intellectual life.
In chapter 8, “The Romance of Orthodoxy,” Chesterton presents the Christian view as the natural foundation for metaphysical, moral, and political freedom, contrasting it with materialism as well as with such religions as Buddhism and Islam. Again and again, he portrays the right thinking of orthodoxy as a thrilling romance, one that renders the profound mystery of life its due, remains in tune with common sense yet is the opposite of received opinion, and retains the power to remind us of the forgotten magic of everyday truth.