[Russell] Blackford’s argument is based on a familiar “Just So” story about European history: once upon a time Catholics and Protestants started killing each other over religion. The secular state saved the day by making religion a private matter. Locke is the hero here for conceptualizing this amicable division: the church would stay out of politics, and the state would stay out of religion. And they all lived happily ever after.
Unfortunately, this tale does not become more true simply by being repeated. It is a favourite of liberal political theorists – John Rawls, Richard Rorty and many others – but it can’t be found in the work of any respected historian of the sixteenth and seventeenth centuries.