No one more starkly differentiated the American idea of liberty from that of secular France than Alexis de Tocqueville. In its true light, he wrote, American civilization

is the product … of two perfectly distinct elements which elsewhere have often been at war with one another but which in America it was somehow possible to incorporate into each other, forming a marvelous combination. I mean the spirit of religion and the spirit of freedom.

The continental idea of liberty is secular. In America, by contrast, the fires of independence were lit from the pulpits of Puritan and evangelical churches. The continental idea pits liberty against law. Americans sing, “Confirm thy soul in self-control / Thy liberty in law.” In America, liberty is not about doing what you feel like doing, but about doing what you know you ought to do. It is self-government, self-mastery, self-control. It is a sense of duty, personal responsibility, and honor.

This particular idea of liberty— although an idea of very long lineage— helps to explain why in America religion and liberty formed “a marvelous combination.” In America, at least, Tocqueville observes:

Freedom sees religion as the companion of its struggles and triumphs, the cradle of its infancy, and the divine source of its rights. Religion is considered as the guardian of mores, and mores are regarded as the guarantee of the laws and pledge for the maintenance of freedom itself.

Ben Franklin proposed as the national motto “Rebellion against tyrants is obedience to God.” The Virginians defined liberty of conscience as a natural right. They based “the first secular nation” on Judeo-Christian premises about God and conscience—that is, acknowledging not the right of Americans alone, nor of Christians and Jews alone, but of all human beings, including “Mahometans, Hindoos,” and atheists.

There are, alas, many jihadist fascists on this planet who do not believe in such a natural right and are determined to crush all who do. There is also an internal danger. No longer, it appears, are religion and freedom in America working in “marvelous combination.” No longer do they see each other as companions.

To continue a reasoned dialogue, worthy of secular and religious people alike, both sides must show mutual respect and work hard to see the world through the eyes of the other, if only as a gesture of mutual honor.

Events are drawing Americans into ever-deeper spiritual and rational self-examination. Our idea of freedom has both secular and biblical roots—in Greece and Rome as well as the British Enlightenment, and in the concept that the Creator is spirit and truth, and sees directly into the conscience of each of us. The link between conscience and Creator is inalienable—no one dares interfere with it. Before the Creator, each of us is empowered to say no as well as yes. Thus in its religious roots, the American idea of freedom recognizes the free consciences of all.

This distinctive concept of liberty is a great strength. But it is also fragile, for it is rooted in ideas. To break the transmission of those ideas requires only a single generation of inattentiveness, under the constant fire of what Abraham Lincoln called “the silent artillery of time.”