FOR a couple of recent postings, I had to consult the constitution of the Republic of Ireland, which still has many references to the spiritual, despite the removal in 1973 of a line about the special position of the Roman Catholic church, and the ongoing arguments over its provisions on reproductive matters. That got me thinking about how many other countries' constitutions have a religious dimension. The "religiosity" of a country's basic law, as I discovered, generally tells you more about its political history than about the religious feelings of its present-day population. The American constitution contains no reference to God, unless you count the words "In the year of our Lord..." During the civil war, there was an unsuccessful movement (on the northern side) to insert an explicitly Christian amendment. To many early Americans, it must have felt strange to live in a country which had no established religion, and where the First Amendment made clear there would never be one. But remember, America's founders were keen to distance themselves from the harsh and divisive theocracies of Europe.

Meanwhile many European countries, whose populations are less devout than America's, retain some reference to God or religion in their system or founding charter. Under Britain's unwritten constitution, the monarch is head of the Church of England and guarantor of a different church in Scotland. In Norway, where I have just arrived for a human-rights conference called the Oslo Freedom Forum, there have been some moves to loosen the link between state, church and crown, but the process is incomplete. The country no longer recognises the Lutheran church as the established faith, but it is still officially designated as the "people's church" and the monarch must belong to it. If you have a monarchy whose authority is (however vestigially) spiritual as well as temporal, then you have a political system which is not entirely secular.

Even in some more recent European charters, the Deity is present. The German federal constitution of 1949 begins with an invocation to God. Spain's constitution does not mention God but it does call for "appropriate co-operation" with the Catholic and other churches. When the European Union's constitutional treaty was being negotiated, there were hard arguments over whether to mention Christianity or God; in the end, a reference was made to the "cultural, religious and humanist inheritance" of Europe.

The Greek constitution has elaborate religious provisions. It begins with the words: "In the name of the holy, one-in-essence and indivisible Trinity" and calls Orthodox Christianity the "prevailing religion". It recognises two institutions: the Archdiocese of Athens and the Patriarchate of Constantinople. It says no translation of holy writ from the original Greek into a more modern form can take place without a nod from those two bodies. A whole section of the constitution safeguards Mount Athos, a monastic polity. Greece, Ireland and Norway have something in common; they owe their statehood to a 19th- or early 20th-century reaction against foreign domination, a time when religion and patriotism sometimes blurred. That may explain their founding documents' theocratic tinge.

In post-communist states, even those where Christianity, Islam or Buddhism now play an important role, there are very few references to God or religion in constitutional documents. But Ukraine and Poland, on the rebound from both Marxism and Soviet/Russian domination, are exceptions that do invoke the Deity. The Polish constitution says it speaks both on behalf of those who believe in God and those who do not. The Russian federation has no official religion, and nor, broadly, do its constituent states, although Islamic law has been proclaimed in Chechnya. Some parts of Russia, like Kalmykia and Buryatia, are historically Buddhist but (in contrast with say, Bhutan) that faith is not built into their governance.

In most Muslim-majority states (Turkey is an exception), the constitution makes at least some reference to Islam, and that was true even in the days when secular nationalism was at its peak. But in countries affected by the Arab spring, the role of Islam and sharia law has grown more explicit. Egypt's new constitution enshrines not only sharia, but the jurisprudence of Sunni Islam as defined by its leading scholars. To the embarrassment of their Western protectors, both Iraq and Afghanistan have adopted Islamically tinged constitutions. But Noah Feldman, a Harvard law professor who helped draft the constitution of Iraq, has urged Westerners to understand why, in some circumstances, Islamic law and governance seem appealing. Islamic law implies at least some constraint on the leader; that is an improvement on secular totalitarianism.

As a general rule, I found, a constitution says more about where a country is coming from—which bits of history it wants to celebrate, and which bits it wants to flee from or avoid—than about how the nation is now, or where it wants to go.