There are sundry interpretations of Islam. Yet, for our limited national-security and liberty-preserving purposes, it is undeniable — except to those who are in terminal denial — that a mainstream interpretation of Islam rejects the foundations of our Constitution, beginning with our core premise that the people are sovereign and may govern themselves irrespective of the totalitarian dictates of sharia.

It makes no difference to us whether this mainstream interpretation of Islam is a faithful rendering — much less the faithful rendering. For our purposes, what matters is that many millions of Muslims, rightly or wrongly, adhere to this construction. One need not fancy himself an Islamic scholar to see that it derives from Islamic scripture, although Dr. Krauthammer must know that there is no shortage of globally influential Islamic scholars who vouch for this literalist fundamentalism — see, e.g., Reliance of the Traveller, the classic sharia manual endorsed by the faculty at Cairo’s al-Azhar University (the seat of Islamic learning since the tenth century) and the International Institute of Islamic Thought (the Muslim Brotherhood’s American think tank, whose self-proclaimed mission is “the Islamization of knowledge”).

Krauthammer thus makes another rudimentary error in addressing Islam as if it were a mere “religion,” like any other one. Throughout this column, I have used the term “belief system,” rather than “religion,” advisedly. Islam, in its classical interpretation, is a comprehensive sociopolitical system with its own legal code. Yes, it has some strictly theological tenets (e.g., the oneness of Allah, the conceit that Mohammed is the final prophet). These, however, comprise but a small percentage of Islamic belief, which covers the full extent of political, economic, and social life — from warfare to hygiene, in exacting rules resistant to change. That is why in virtually every Islamic society — i.e., wherever sharia is incorporated into law — the separation of spiritual and political life is rejected; it is why we find misogyny, anti-Semitism, homophobia, ruthless discrimination against religious minorities, hostility to freedom, suspicion of reason, and backwardness in economics and education.