On Numbers: Odd and Even Numbers

“I can show you that the art of computation has to do with odd and even numbers in their numerical relations to themselves and to each other.” (Plato, “Charmides”, cca. 5 century BC)

“Uneven numbers are the god’s delight” (Virgil, “The Eclogues”, cca. 40 BC)

“Why do we believe that in all matters the odd numbers are more powerful […]?” (Pliny the Elder, “Natural History”, cca. 77-79 AD)

“Numbers are called prime which can be divided by no number; they are seen to be not ‘divisible’ by the monad but ‘composed’ of it: take, for example, the numbers live, seven, eleven, thirteen, seventeen, and others like them. No number can divide these numbers into integers. So, they are called `prime,' since they arise from no number and are not divisible into equal proportions. Arising in themselves, they beget other numbers from themselves, since even numbers are begotten from odd numbers, but an odd number cannot be begotten from even numbers. Therefore, prime numbers must of necessity be regarded as beautiful.” (Martianus Capella, cca. 400 AD)

“Number is divided into even and odd. Even number is divided into the following: evenly even, evenly uneven, and unevenly uneven. Odd number is divided into the following: prime and incomposite, composite, and a third intermediate class (mediocris) which in a certain way is prime and incomposite but in another way secondary and composite.” (Isidore of Seville, Etymologies, Book III, cca. 600)

“There is divinity in odd numbers, either in nativity, chance, or death.” (William Shakespeare, “The Merry Wives of Windsor”, 1602)

"For any number there exists a corresponding even number which is its double. Hence the number of all numbers is not greater than the number of even numbers, that is, the whole is not greater than the part." (Gottfried W Leibniz, “De Arte Combinatoria”, 1666)

“We know that there is an infinite, and we know not its nature. As we know it to be false that numbers are finite, it is therefore true that there is a numerical infinity. But we know not of what kind; it is untrue that it is even, untrue that it is odd; for the addition of a unit does not change its nature; yet it is a number, and every number is odd or even (this certainly holds of every finite number). Thus, we may quite well know that there is a God without knowing what He is.” (Blaise Pascal, “Pensées”, 1670)