In many
polytheistic religions, such as those of ancient India and Iran (the most ancient of which go back to a common Indo-Iranian period), Greece and Rome, a deity's epithets generally reflected a particular aspect of that god's essence and role, for which their influence may be obtained for a specific occasion: Apollo is "
Apollo, [as] leader of the
Muses" and therefore patron of the arts and sciences, while
Phoibos Apollo is the same deity, but as shining sun-god. "
Athena protects the city as , oversees handicrafts as , joins battle as and grants victory as ." Alternatively, the epithet may identify a particular and localized aspect of the god, such as a reference to the mythological place of birth or
numinous presence at a specific sanctuary: sacrifice might be offered on one and the same occasion to Pythian Apollo (
Apollo Pythios) and Delphic Apollo (
Apollo Delphinios). A localizing epithet refers simply to a particular center of veneration and the cultic tradition there, as the god manifested at a particular festival, for example: Zeus Olympios, Zeus as present at Olympia, or Apollo Karneios, Apollo at the Spartan
Carneian festival. Often, the epithet is the result of the fusion of the Olympian divinity with an older one.
Poseidon Erechtheus and
Artemis Orthia reflect intercultural equations of a divinity with an older one that is generally considered its pendant. Thus, most Roman gods and goddesses, especially the
Twelve Olympians, had traditional counterparts in Greek, Etruscan, and most other Mediterranean pantheons, such as
Jupiter as head of the Olympian Gods with
Zeus. But in specific cults, there may be a different equation, based on one specific aspect of the divinity. Thus, the Greek word ("thrice grand") was first used as a Greek name for the Egyptian god of science and invention,
Thoth, later as an for the Greek
Hermes and, finally, the fully equated Roman Mercurius
Mercury (both were messengers of the gods). Among the Greeks, T.H. Price notes that the nurturing power of might be invoked in sacrifices and recorded in an inscription, without specifically identifying
Hera or
Demeter. Some epithets were applied to several deities of the same pantheon rather accidentally if they had a common characteristic, or deliberately, emphasizing their blood or other ties. Thus, in pagan Rome, several divine gods and heroes were given the
Comes as a companion of another (usually major) divinity. An epithet can even be meant for collective use, e.g., in Latin , "the felt hat-wearers" for the brothers
Castor and Pollux. Some epithets resist explanation. Catholics,
Eastern Orthodox Christians, and Christians of other churches practice the use of epithets in the veneration of
Jesus (e.g., "Christ"; "
Prince of Peace"; "
The Good Shepherd"), of
Mary, Mother of Jesus (e.g., "
Mother of God"; "
Panagia"), and of the saints (e.g., "
Pope Saint John Paul the Great,
Saint Theophan the Recluse"). "
Our Lady of Lourdes" is essentially
periphrasis, except where some aspect of the Virgin is invoked. ==Rhetoric==