Regardless of their sometimes ambiguous concepts of God, the Roman Stoic philosophers did acknowledge Him, but on the basis of reason alone, because they had not met Christ. Nonetheless, they did deduce from God's existence our need to live lives of virtue, honor, tranquility, and self-control--and they developed effective techniques to help us achieve this. Musonius Rufus the teacher, Epictetus the slave, Seneca the adviser to emperors, and Marcus...