Pythagoras of Samos is often described as the first pure mathematician. But he is also an extremely important figure in the development of Greek philosophy. No authentic writings of Pythagoras have survived, and almost nothing is known for certain about his life. However, his impact on successive thinkers has been enormous. "PYTHAGORAS AND THE DELPHIC MYSTERIES", written from an esoteric perspective, is a good introduction to the man and his thought.