A Hermetic name is how the maga is known to her fellow magi, and likely to her servants and companions. Many magi choose to put their past behind them, and ignore old familial or community ties that once bound them. Childhood suffering under the effects of the Gift may thus be assigned to a past life, one that no longer has meaning for the magus. A new name and identity symbolizes this break with the past.

The tradition of "Hermetic" names predates the Order, deriving from the Roman custom of the cognomen, which originated as a "nickname." Wizards of the Mercurian tradition often went by a cognomen: Flambeau was not given that name by his mother, nor was Bonisagus, Tremere, or most of the other Founders. The Domus names are cognomena, as are many lineage names within the Order.

For some magi, Hermetic names are given to them by their parentes, who make them "official" when they present the new magi at Tribunal. Often, a parens will adopt the same approach to the sigil of the new maga, presenting both a name and a sigil of the parens' choice to represent the former apprentice. The name chosen, like the cognomena of ancient Rome, may call attention to a particular talent, personality trait, or achievement. Sometimes, as with Flambeau, the nature of the maga's magic may lend itself to a name. For others, the name may symbolize the nature of the relationship between parens and filius.

Some Domus have specific traditions that many or most magi of the Domus follow, and some lineages may have traditions regarding naming or sigils. Other parentes leave the choosing of a Hermetic name, and a sigil, to their former apprentices, asking them only by what name they wish to be known to the Order.

Due in part to the tradition of cognomena, many magi choose "Latin" names, or latinized names. Within some lineages, this is traditional. Other magi may choose latinized names as a means of further distancing themselves from their past.

Latinized names are by no means universal, however. Magi of non-Roman traditions such as Domus Bjornaer and Ex Miscellanea, for example, rarely have latinized names, and magi of other Domus may select a different sort of name for various personal reasons. Those who study the history of the Order have noted several trends, in which latinized names become very popular for a few decades, and then gradually lose popularity for awhile. Such patterns are easier to identify, they claim, if one knows which lineages rarely change their naming practices.