Great minds and noble spirits have gone before us in the field of geometry. Still living is one whose influence in the modern renaissance of philosophical geometry is primary. he is our Pythagoras, a revealer of neglected truths and a teacher who has inspired and transformed generations of students from all parts of the world. His pupils and followers include practically everyone listed below. This book is dedicated to our master geometer: KEITH CRITCHLOW

With a hearty thanks to the following for the various ways they have all assisted with this work: Richard Adams, Sam Adams. Alex Brown. Christopher Gibbs, Michael Glickman, Jason Godwin, Merrily Harpur, Frances Howard-Gordon, John James, Robert Lawlor, Roland Marti ('amicable' paper cutting on page 236), John Martineau, Joan Moore, Alex Munslow, John Neal, Scott Olsen, Christine Rhone, Michael Schneider, Malcolm Stewart, Rosemary Tayloe, and Stephen Wilmoth.