BY KEENLY CONFRONTING THE ENIGMAS THAT SURROUND US, AND BY CONSIDERING AND ANALYSING THE OBSERVATIONS THAT I HAVE MADE, I ENDED UP IN THE DOMAIN OF MATHEMATICS. ALTHOUGH I AM ABSOLUTELY WITHOUT TRAINING IN THE EXACT SCIENCS, I OFTEN SEEM TO HAVE MORE IN COMMON WITH MATHEMEATICIANS THAN WITH MY FELLOW ARTISTS (M. C. Escher)