The letter is, throughout, violent and contemptuous in its tone, with an arrogant assumption that the writer is in possession of the whole truth on the difficult subject on which he writes, and that he has a right to demand from his bishop a confession of faith on each point on which he chooses to catechise him. Its importance lies in the fact that it, to a large extent, fixed the belief of churchmen on the points it deals with, and the mode of dealing with supposed heresy, for more than a thousand years.