Topics: Medieval Philosophy, Christian Thought development, Plotinus Philosophy, Saint Augustine Philosophy, Boethius Philosophy, Saint Anselm Philosophy, John Scotus Erigena Philosophy, Peter Abelard Philosophy, Thomas Aquinas Philosophy, Saint Bonaventure Philosophy, Duns Scotus, William of Ockham, Francis Suarez, Al-Farabi philosophy, Avicenna philosophy, Averroes philosophy, Moses Maimonides philosophy, Solomon Ibn Gabirol philosophy, Ibn Paquda philosophy, Albo Joseph philosophy, Noccolo Machiavelli philosophy, spirit, soul, doctrine of the one, problem of evil, human suffering