Two replies to Mike’s post below.

First, and less important: I am no longer persuaded that Locke’s “mufti” passage, or the general discussion of foreign princes, is meant to convey a general exclusion of Catholicism from toleration. This is how the Letter has traditionally been taught– Mike’s reading is the usual one. But I think it’s wrong.

A) There would be no reason for an English Whig in the era of the Glorious Revolution to dissemble on this point. Catholicism was widely unpopular and the Revolution reversed James II’s Declarations of Indulgence extending de facto toleration to the church. Not only would Locke have not had anything to be embarrassed about by excluding Catholicism as such; it would have been the most normal thing for him to do. It would have pried apart the principle of toleration, and the application of that principle to dissenting Protestants, from (what Whigs and Dissenters took to be) James’ abuse of the principle en route to an eventual establishment of Catholicism. The fact that he doesn’t say that, and at several points includes Catholicism or Papism amongst the indifferent and tolerable religions, suggests that something odd is going on.

B) By 1688, the Church was no longer what it had been at the time when Popes excommunicated whole countries and called for Protestant kings to be overthrown and killed. In the most powerful Catholic state, France, the Church had indeed been decisively subordinated to Louis XIV’s crown. James II was attached to this French Catholicism, so-called Gallicanism. (Louis was his cousin and, in crucial ways, his ideological and religious mentor.) The Vatican was deeply hostile to Louis and to Gallicanism, and was likewise hostile to James’ attempt to re-Catholicize England. Moreover, ordinary English and Scottish Catholics favored the Roman side over the Gallican. What this meant by 1688-89, however, was not that they would be following Papal orders to overthrow their kings; the Vatican hadn’t formally abjured that power but it simply wasn’t in that business anymore.

These add up to the following: I think we should read Locke as offering the principles on which to distinguish among Catholics– and the relationship between the mufti and the Ottoman Emperor isn’t meant to echo the Pope’s relationship to himself, but rather that between the Gallican Church and Louis. Roman Catholics were tolerable– but their intra-Church ideological enemies, the Gallicans who effectively owed allegiance to a literal foreign king, Louis, were not.

Second, and more important: well, of course people who want to refuse toleration to Islam aren’t saying that it’s because Islam is theologically false. Of course they’re putting it in terms of security risks and divided loyalties and consorting with military enemies. That’s how these things go, in the centuries after the Wars of Religion ended in the west. That’s progress, certainly. Locke’s essential argument has won the day in the west: the state has legitimate concerns only with things like security and not with things like theological truth.

But saying that Islam runs afoul of such security and loyalty concerns doesn’t make it so. And Locke’s argument for exclusions from toleration could only be extended to a whole faith if there really were doctrines of the whole faith that were incompatible with peaceful, loyal, and law-abiding citizenship in a nonconfessional state. There’s simply no truth to the claim– none– that Islam as such is like that, and Trump hasn’t proffered any evidence at all in support of it.

To invoke the Lockean secular security concerns in an argument for restricting religious liberty (and the wholesale exclusion of migration on the basis of religion is such a restriction!) is kind of like invoking “falsely shouting fire in a crowded theater” in an argument for restricting freedom of speech. You’ve correctly identified the form of a legitimate exception, but you haven’t yet filled it with any content. The premise of an incompatibility between a religious commitment and the claims of secular order has to be valid for a Lockean argument for exclusion to go through. And, to borrow language from American law, I would also think that the premise has to be as narrowly-tailored as is practicable. We wouldn’t say “because some theists hold allegiance to a foreign prince, we may exclude all theists from toleration.” If I’m right about how to read the Letter with respect to Catholicism, Locke even meant to distinguish among branches of a single denomination, identifying as precisely as possible the group that held the problematic belief and excluding that group.* This, of course, bears no resemblance to anything Trump has said or done.

*He thought atheists as such were the right group to be excluded from toleration on the precise ground that no atheist could meaningfully swear an oath. We don’t have to agree with him about this, but it doesn’t contradict what I’m saying about precision and narrow tailoring.