The most significant theme of this work is the relationship between Christianity and democracy. Maritain argues that democracy is not primarily about developing political institutions such as legislative bodies and developing habits of political participation; instead, democracy is best understood as a social vision that is built upon a view of the human person as one who derives dignity from bearing the image and likeness of God.
Democratic society, according to Maritain, should promote the common good. That common good will be achieved when people exercise what Maritain calls civic friendship. Once civic friendship is exercised, there will be a true justice and peace. Thus there cannot be true Christianity without democracy, because the two are essentially linked.
A second theme in the work is the spread of Christian notions about the person and the manner in which that influences common humanity. Maritain believes that a Christian notion of the human person has permeated Western society. In this sense, one can be a democrat without being an active practitioner of Christianity. Because notions of human dignity have spread to many people, leaders can look to the beliefs of common humanity. Maritain sees these beliefs being held by many in Europe and, most definitely, by many in America.
A third theme of the work is the need for heroic actions on the part of those seeking to restore democracy. Heroic actions by leaders promoting a new understanding of democracy are particularly needed in Europe, because the destruction in Europe in the wake of World War II will require a new social vision. Maritain says that Americans have exercised some heroic action in coming to the aid of democracy in nations battling fascism, and the optimism and hopefulness of Americans can be a model to others around the world.