Just as Plato's theoretical prisoner is freed from captivity and taken to the surface, where he slowly adjusts to light, growing in knowledge of the world and himself to eventually find his ultimate destiny in the light of the sun; Our PCs start imprisoned, not just in a particular dungeon, but in a lifestyle rut. Level-up screen confirm that for most of our character's life, before they became saddled with their quest, they had just drifted through life without direction or real vocation - at one point I believe it's described as "like waking from a dream". Gaining experience, he/she slowly climbs the rungs of destiny, leaving those old wall-shadows behind and embracing the true incandescent face of the Aurbis itself.
I guess what I'm really saying is that no matter what class you think you're playing, you're actually always a Philosopher.