Anglo-American Secular Government

What North Americans and British now call secular government emerged from a series of debates about religious freedom and toleration, which reached their climax in seventeenth-century England. John Locke is often considered the hero of that climax, but he in fact began his career opposing religious freedom. He changed his mind only when he had overcome two pitfalls he initially associated with it: (1) diversity produces civil strife and (2) limited government will always be undermined by manipulative citizens (either believers who make phony claims about their religious duties, or bigots who persecute believers with spurious accusations of treachery). His solution is now taken for granted as the basis of secular government in the USA, UK, and Canada; so much so that we often forget its origins. It continues to influence Anglo-American political thought today, for good and for ill.
Despite its success, the solution is imperfect and subsequent modifications—including minor tweaks by various American Founders, and a more recent reappropriation by John Rawls—have failed to perfect it. Its most notable imperfection is a naïve hope that all imaginable future theo-political disputes will be solved by abstract, neutral principles, specifiable-in-advance of the disputes themselves. This leads to animosity and accusations of bias when tricky cases are not so easily solved. It would be better to acknowledge that some disputes can only be solved ad hoc.