In numerology, isopsephy (stressed on the I and the E;Variously , ; also , , ) or isopsephism is the practice of adding up the Greek numerals in a word to form a single number. The total number is then used as a metaphorical bridge to other words evaluating the equal number,6 which satisfies isos or "equal" in the term. Ancient Greeks used for numerical calculation and accounting, with a counter generically called psephos ('pebble'), analogous to the Latin word calculus, from which the English calculate is derived.
Isopsephy is related to gematria: the same practice using the Hebrew alphabet. It is also related to the ancient number systems of many other peoples (for the Arabic alphabet version, see Abjad numerals). A gematria of Latin script languages was also popular in Europe from the Middle Ages to the Renaissance, and its legacy remains an influence in code-breaking and numerology.
An early reference to isopsephy, albeit of more-than-usual sophistication (employing multiplication rather than addition), is from the mathematician Apollonius of Perga, writing in the 3rd century BC. He asks: "Given the verse: ΑΡΤΕΜΙΔΟΣ ΚΛΕΙΤΕ ΚΡΑΤΟΣ ΕΞΟΧΟΝ ΕΝΝΕΑ ΚΟΥΡΑΙ ('Nine maidens, praise the glorious power of Artemis'), what does the product of all its elements equal?"
More conventional are the instances of isopsephy found in graffiti at Pompeii, dating from around 79 AD. One reads "I love her whose number is 545." Another says "Amerimnus thought upon his lady Harmonia for good. The number of her honorable name is 45."
Suetonius, writing in 121 AD, reports a political slogan that someone wrote on a wall in Rome:
the same value as:
A famous example is 666 in the Biblical Book of Revelation (13:18): "Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six." The word rendered "count", ψηφισάτω, , has the same "pebble" root as the word isopsephy.
Also in the 1st century AD, Leonidas of Alexandria created isopsephs, epigrams with equinumeral distichs, where the first hexameter and pentameter equal the next two verses in numerical value. He addressed some of them to Nero:
A headstone found at the Temple of Artemis at Sparta Orthia is a 2nd-century AD example of isopsephic elegiac verse. It says:
This alphabetic system operates on the additive principle in which the numeric values of the letters are added together to form the total. For example, 241 is represented as σμα (200 + 40 + 1).
a |
b |
g |
d |
e |
w / st |
z |
ē |
th |
i |
k |
l |
m |
n |
x |
o |
p |
q |
r |
s |
t |
y |
ph |
ch |
ps |
ō |
ts |
|
|