The Gnostics

plato(c. 424–423 BC to c. 348–347 BC) A Greek philosopher who helped lay the foundations for Western civilization. An initiate of the esoteric mystery schools, he was heavily criticized for revealing too much of the secret doctrine to the public.

"Plato was initiated into the 'Greater Mysteries' at the age of 49. The initiation took place in one of the subterranean halls of the Great Pyramid in Egypt. The ISIAC TABLE formed the altar, before which the Divine Plato stood and received that which was always his, but which the ceremony of the Mysteries enkindled and brought from its dormant state. With this ascent, after three days in the Great Hall, he was received by the Hierophant of the Pyramid (the Hierophant was seen only by those who had passed the three days, the three degrees, the three dimensions) and given verbally the Highest Esoteric Teachings, each accompanied with Its appropriate Symbol. After a further three months' sojourn in the halls of the Pyramid, the Initiate Plato was sent out into the world to do the work of the Great Order, as Pythagoras and Orpheus had been before him." - Thomas Taylor, quoted by Manly P. Hall in The Secret Teachings of All Ages (1923)

"Voltaire said that Plato should have been canonized by the Christian Church, for, being the first propounder of the Christos mystery, he contributed more to its fundamental doctrines than any other single individual." - Manly P. Hall