Onomancy or onomamancy is a form of divination by names. Satirically speaking, some think it is more like divination by a donkey. They claim a more appropriate term for it would be onomamancy, or onomatomancy. The theory that there is an analogy between men’s names and their fortunes supposedly originated among the Pythagoreanism; it produced some speculation concerning Plato. Also, it was a source of witticism by Ausonius, which probable amused some classical scholars to collect his epigrams.
There were two cardinal rules in the science of onomancy: the first concerned the vowels within a man’s name. If there was an even number in the name, then there was something amiss in his left side. If the vowel were uneven, this signified a similar affliction in his right side. This left little room for sanity between the two.
The second rule involved the numeral numbering of all the letters within a name. This rule was often used to predetermine the winner of two combatants. The person having the name in which the letters added up to the greater sum was always picked to be the winner. This was how Achilles was chosen to triumph over Hector.
The second rule of onomancy relates to arithmancy. A.G.H.