Sophia (wisdom)
Sophia (σοφία, Greek for "wisdom") is a central idea in Hellenistic philosophy and religion, Platonism, Gnosticism, Orthodox Christianity, Esoteric Christianity, as well as Christian mysticism. Sophiology is a philosophical concept regarding wisdom, as well as a theological concept regarding the wisdom of the biblical God.
Sophia is honored as a goddess of wisdom by Gnostics, as well as by some Neopagan, New Age, and Goddess spirituality groups. In Orthodox and Roman Catholic Christianity, Sophia, or rather Hagia Sophia (Holy Wisdom), is an expression of understanding for the second person of the Holy Trinity, (as in the dedication of the church of Hagia Sophia in Constantinople) as well as in the Old Testament, as seen in the Book of Proverbs 9:1, but not an angel or goddess.
Platonism
Plato, following his teacher, Socrates (and, it is likely, the older tradition of Pythagoras), understands philosophy as φιλοσοφία (philo-sophia, or, literally, a friend of Wisdom). This understanding of philosophia permeates Plato's dialogues, especially the Republic. In that work, the leaders of the proposed utopia are to be philosopher kings: rulers who are friends of sophia or Wisdom.