While in England, Mr. Williams, notwithstanding the pressure of his duties, and the disturbed state of the public mind, found leisure to prepare for the press his celebrated book, entitled “The Bloody Tenet of Persecution for Cause of Conscience, discussed in a conference between Truth and Peace, who, in all tender affection, present to the High Court of Parliament, as the result of their discourse, these amongst other passages of highest consideration.” In this book, which he dedicated to Parliament, and which was doubtless read, with interest and profit, by many of the leading men in England,[248] Mr. Williams discusses the great principles of religious liberty, in answer to a letter of the Rev. John Cotton. Mr. Cotton wrote a reply, to which, in accordance with the humor of those times, he gave the quaint and punning title of “The Bloody Tenet Washed, and made White in the Blood of the Lamb.” Mr. Williams published a rejoinder, with a title in the same strain, “The Bloody Tenet yet more Bloody, by Mr. Cotton’s Endeavor to Wash it White.” Of these books we shall give some account, in a subsequent chapter. It may suffice now, to say, that Mr. Cotton’s argument rests on a sophistical distinction between persecution for religious opinions, and punishment for maintaining errors. He disclaims the right to “persecute any for conscience rightly informed;” but if a man possesses “an erroneous and blind conscience, in fundamental and weighty points,” he ought, after suitable admonition, to be punished by the civil magistrate, not because he entertains heretical principles, but because he is wilfully blind and criminally obstinate, in refusing to believe what is clearly revealed in the Scriptures. It seems surprising, that a man of Mr. Cotton’s abilities and virtues, could seriously maintain so transparent an absurdity; for if the magistrate be allowed to judge what is “an erroneous and blind conscience,” he will decide according to his own construction of the word of God, and will pronounce all who differ from himself to be culpably obstinate, and worthy of punishment. This is precisely the case in every instance of persecution; and the Court of High Commission, who expelled Mr. Cotton from England, would have needed no other defence of their conduct than his own arguments. But Mr. Cotton, though a great and a good man, was misled by his views of the duty of the civil magistrate to interfere, for the preservation of purity in the Christian church, as the civil authorities were required to guard the Jewish religion, and to smite, with unsparing severity, those who renounced or corrupted it.