Gilbert Chesterton is rightfully recognized as a classic of the English detective story. But few people know that he wrote not only about the Catholic priest Father Brown. His light journalistic pen belonged to treatises on Christianity, for example, The Eternal Man and historical studies on the Catholic saints Thomas Aquinas and Francis of Assisi. As Chesterton himself said about St. Francis: “This great and amazing man can be considered as a historical figure and the embodiment of social virtues and as the only democrat in the world." And the author’s conclusion is absolutely accurate that St. Francis overtook his age and anticipated all the best, liberal, good that is in the modern world.