The preachers quickly learned that he could trade biblical quotations with them almost indefinitely. It was equally pointless to cite the standard Presbyterian authorities. James denounced John Calvin's Institutes of the Christian Religion as 'childish', dismissed John Knox as 'a knave' who ha called 'his mother a whore', and informed the minister who claimed a divine warrant to preach that 'the office of prophets was ended'. The preachers could only suffer his sarcasm in silence.