What is numerology?

In the common Western method each letter of the alphabet takes a value from 1 to 9, repeating as the alphabet runs on. The letters of a name are added together, and the digits of the total are added until one digit remains. A birth date is reduced the same way.

Older number lore is a separate thing. People have long given numbers symbolic meaning, and in Greek and Hebrew the letters themselves served as numerals. The word numerology is first recorded in English around 1907. Before that, divination by numbers was called arithmancy.

A numerologist works out a number from the birth date, a number from all the letters of the birth name, and further numbers from its vowels or consonants, and then reads a set meaning for each. Many keep 11 and 22 unreduced as Master Numbers. The Gale Encyclopedia of the Unusual and Unexplained notes that interpretations of the nine numbers vary between practitioners.

The results depend on the method chosen, so the same name can yield different numbers from different teachers.

Pythagoras lived from about 570 to about 490 BCE, on Samos and then in southern Italy. No source from his own time or the next two centuries quotes a work by him, and several later ones say he wrote nothing. Aristoxenus, writing in the fourth century BCE, says he took number away from the use of traders and likened things to numbers. Aristotle reports examples of the kind: two as female, three as male, five as marriage.

Philolaus, a later Pythagorean, wrote that things are known through number. Writers of later centuries then credited Pythagoras with far more than the early evidence shows, and forged treatises circulated under his name.

Letter counting has its own history in Jewish interpretation. The term gematria first appears in a list of interpretive rules from about 200 CE, and a classic rabbinic example finds the value 318 in the name Eliezer.

Heinrich Cornelius Agrippa published his Three Books of Occult Philosophy in 1533, and an English version followed in 1651. A chapter of the second book names arithmancy and credits the Pythagoreans with holding that letters carry numbers. Its table for Latin letters runs on a different plan from the modern one: A to I are 1 to 9, K to S are 10 to 90, and T onward are hundreds. Agrippa adds the values of a child's and parents' names and divides by nine to find a ruling planet.

The method in use today takes shape around Mrs. L. Dow Balliett of Atlantic City, New Jersey. Her How to Attain Success Through the Strength of Vibration, copyright 1905, carries the subtitle A System of Numbers as Taught by Pythagoras. It divides the alphabet into nine groups, reduces names and birth dates to a digit, and gives special weight to the first vowel of a name. The word numerology does not appear in the book. A review of the mathematician Underwood Dudley's 1997 book on the subject reports his view that she virtually invented the modern practice.

The palmist known as Cheiro helped spread a further version. His Book of Numbers of 1926 sums the digits of a birth date to give a number of destiny tied to a planet.

The tie to Pythagoras is unsupported. Balliett credits him and mentions the Bible, Plato and other philosophers in general terms, and she gives no source for her letter table. The early evidence gathered by the Stanford Encyclopedia of Philosophy concerns the symbolism of numbers themselves. Later writers such as Agrippa connect letter values to the Pythagoreans, and that connection is a late report. No ancient or medieval text read for this site states the A to I, J to R, S to Z table.

Agrippa's chapter shows that summing a name to foretell events was known in the sixteenth century. It uses another letter scale, so it does not connect directly to the modern table.

The reference works consulted here describe the methods and cite older books. None reports a test showing that a name or date reveals character or the future.