Theosophical addition

Theosophical addition consists of adding all the numbers from 1 up to the number under study: for 4, this gives 1 + 2 + 3 + 4 = 10, which reduction brings back to 1. Late nineteenth-century occultists, Papus in particular, used it to show how a number “contains” those before it and leads back to unity. It is sometimes confused with theosophical reduction, which only adds up the digits of a number; depending on the author, the two expressions are not always used rigorously.