From 'Straight and crooked thinking' by Robert H. Thouless, Pan Books, ISBN 0 330 24127 3, copyright 1930, 1953 and 1974.
A marvelous resource.
Updated 10/22/2011: The original link has vanished and the domain was acquired. I can't find a summary of the book online, but I found a PDF that can be downloaded from the 1953 edition. A wikipedia article lists some key excerpts.