In the summer of 1704, English philosopher John Locke began writing a response to a critic of his controversial treatise on religious freedom, A Letter Concerning Toleration (1689). It was, in fact, the third letter from Locke addressed to Jonas Proast, a chaplain at Oxford University, who insisted that government coercion in religious matters was necessary to preserve social order. Locke fired back: "Men in all religions have equally strong persuasion, and every one must judge for himself," he wrote. "Nor can any one judge for another, and you last of all for the magistrate."
Locke died before finishing the letter, but his revolutionary voice is being heard once again. A manuscript titled "Reasons for Tolerating Papists Equally with Others," written in Locke's hand in 1667 or 1668, has just been published for the first time, in The Historical Journal of Cambridge University Press. The document challenges the conventional view that Locke shared the anti-Catholicism of his fellow Protestants. Instead, it offers a glimpse into the radical quality of his political liberalism, which so influenced the First Amendment and the American Founding. "If all subjects should be equally countenanced, & imployed by the Prince," he wrote, "the Papist[s] have an equall title."