Phosphorus (morning star)

Phosphorus (Ancient Greek: Φωσφόρος, romanized: Phōsphoros) is the god of the planet Venus in its appearance as the Morning Star.

Depending on the orbital locations of both Venus and Earth, it can be seen in the eastern morning sky for an hour or so before the Sun rises and dims it, or (as the evening star) in the western evening sky for an hour or so after the Sun sets, when Venus itself then sets.

This may lie behind myths about deities associated with the morning star proudly striving for the highest place among the gods and being cast down.

[8] In the philosophy of language, "Hesperus is Phosphorus" is a famous sentence in relation to the semantics of proper names.

Saul Kripke used the sentence to posit that the knowledge of something necessary — in this case the identity of Hesperus and Phosphorus — could be discoverable rather than known a priori.