Bunyan clearly draws on his experiences in prison to detail the scene at the Interpreter’s house: the haunting sight of a despairing man in an iron cage. Bunyan himself was in an iron cage of his own when he started writing the book, and it is hard to avoid the suspicion that Bunyan saw himself in this former professor who had a religious crisis from which he never quite recovered. No doubt Bunyan’s time in jail was marked by deep despair and hopelessness. But by sending Christian on his journey, Bunyan shows that he is freer than the caged man. In his imagination and spirit he can create a character that progresses, even if his body is behind bars.