Quote from : Jonathan Strange & Mr Norrell Book

He had discovered that it was easier – far easier than any one could have supposed – to make oneself mad, but like all magic it was full of obstacles and frustrations. Even if he succeeded in summoning the fairy (which did not seem very likely), he would be in no condition to talk to him. Every book he had ever read on the subject urged magicians to be on their guard when dealing with fairies. Just when he needed all his wits, he would have scarcely any wits at all.