“But in the essence of number, or in the first original one, all other numbers, and consequently the elements of numbers, and the elements of the whole world, and all nature, are contained. The elements of number are the even and the odd; on this account the first one is the even-odd, which the Pythagoreans, in their occasionally strained mode of symbolizing, attempted to prove thus; that one being added to the even makes odd, and to the odd, even.”