Mathematics became an important part of the Pythagorean's beliefs to the extent that natural numbers, 1, 2, 3, 4, 5 were considered the most fundamental elements of nature; the number 1 was the origin of all things; all things could be reduced to numbers; 10 was the best of all num bers; and 17 was a number to be greatly feared. The five pointed star formed by the diagonals of a regular pentagon was the"badge" or mark of Pythagoreans. Such star-pentagons were well known by the Babylonians