Pallas Athena

The Athena Giustiniani, a Roman copy of a Greek statue of Pallas Athena (Vatican Museums)

Known in Mythology as Pallas Minerva, Athene, or Athena, which means Virgin. She was the Goddess of Wisdom, War and the Liberal Arts and Sciences; was produced from Jupiter's brain without a mother. The olive, the emblem of peace, belongs to her. She is usually represented as wearing a helmet, her right hand holding a speare to strike at a serpent near her feet, the owl and the cock being her favourite birds symbolically.
Athena was known as the spear-shaker among the ancient Greeks. They placed her statue on their temples. When the rays of the sun danced on her spear, it seemed as though Athena was shaking it . . . hence her name, the Spear-Shaker.
"AthenA" was Francis Bacon's muse. He calls her "the tenth muse ten times more in worth than those old nine the rhymers invocate". (Sonnet 38). There were supposed to be nine muses only. He used the first and last letters of her name as head pieces to mark books connected with the Rosicrosse. There were many different designs of this double "A.A.". Numerous books in their era bear the signal,  including the authorized edition of the James Bible and the Shakespeare Plays. One "A" was printed light and the other "A" was dark to indicate that while there was much open and straightforward in the book there was also much in the shadow which could only be discovered by searching. (Dodd, The Martyrdom of Francis Bacon, p. 176)