A common theory about freedom of religion suggests that such a value is grounded in a modus vivendi, or compromise: People agree to respect each other's freedom in order to avoid religiously motivated strife. But the modus vivendi theory obscures the deep ground of principle on which the right of religious liberty rests and the true reasons for respecting the religious freedom of others.
As a Republican and a Democrat on the U.S. Commission on International Religious Freedom, we are committed, with our colleagues, to advancing religious liberty around the globe. One of our goals is to make clear that such liberty is not simply a matter of sensible social compromise, or just an American ideal or a Western value, but an essential element of human dignity.
We humans reflect on our condition and inquire into the origins of the cosmos and the meaning of our lives. We seek answers to the deepest questions: Where do we come from? What is our destiny? Is there a transcendent source of meaning and value? Is there a "higher law" that obliges us to rise above our personal interests and desires in order to "do unto others as we would have them do unto us"?
Many of us grasp the point of this quest because we experience ourselves as more than merely material beings tied to nature's necessities. Our most immediate and intimate experiences of ourselves are as free and rational creatures—agents capable of choosing, thus helping to shape our world. We sense that we are responsible for our own actions, and we judge that others, by the same token, are responsible for theirs.
Some argue that this experience is illusory, and that we are determined in our actions purely by material causes. But these arguments themselves presuppose that the quest to understand the truth about the human condition is a deeply worthy one. They honor the questions that give rise to the quest, even in proposing answers meant to establish its futility.
To respect fundamental human rights is to favor and honor the person who is protected by those rights—including the rights to freedom of speech, press, assembly and religion.
To respect the person is to favor human flourishing in its many dimensions. For those who regard humans not just as material beings but also as spiritual ones—free, rational and responsible—it is obvious that their spiritual well-being is no less important than their physical, psychological, intellectual, social and moral well-being.
It should be equally obvious that respect for the flourishing of people requires respect for their freedom—as individuals and together with others in community—to address the deepest questions of human existence and meaning. This allows them to lead lives of authenticity and integrity by fulfilling what they conscientiously believe to be their religious and moral duties.
Religious faith by its nature must be free. A coerced "faith" is no faith at all. Compulsion can cause a person to manifest the outward signs of belief or unbelief. It cannot produce the interior acts of intellect and will that constitute genuine faith.
Coercion in the cause of belief, whether religious or secular, produces not genuine conviction, but pretense and inauthenticity. It is therefore essential that religious freedom include the right to change one's beliefs and religious affiliation. It also includes the right to witness to one's beliefs in public as well as private, and to act—while respecting the equal right of others to do the same—on one's religiously inspired convictions in carrying out the duties of citizenship. Religious liberty includes a heavy presumption against being coerced to act contrary to one's sense of religious duty. This is a presumption that can be overridden only when necessary to achieve an essential public interest and when no less-restrictive alternative exists.
Because the freedom to live according to one's beliefs is so integral to human flourishing, the full protections of religious liberty must extend to all—even to those whose answers to the deepest questions reject belief in the transcendent.
The British religious thinker John Henry Newman observed in 1874 that "conscience has rights because it has duties." We honor the rights of conscience in matters of faith because people must be free to fulfill what they believe to be their solemn duties.
Since America's founding, the country has honored this form of liberty. Today, when religious freedom in many parts of the world is under siege, one of the aims of U.S. foreign policy should be to combat such intolerance—not just because religious freedom reduces the risk of sectarian conflict, but more fundamentally because it protects the liberty that is central to human dignity.
Mr. George is a professor of jurisprudence at Princeton University and a visiting professor at Harvard Law School. Ms. Lantos Swett is president of the Lantos Foundation for Human Rights and Justice. They are, respectively, chairman and vice chairwoman of the U.S. Commission on International Religious Freedom.