Book excerpt: In the Enneads, 3rd century mystic philosopher Plotinus synthesized a thousand years of accumulated Greek wisdom with his own profound mystical experiences. What is the nature of God? Of spirit? Of soul? In what fashion can God be realized? How can the validity of spiritual experiences be tested? Return to the One presents Plotinus's compelling answers to such ageless questions in a refreshing modern style. Whatever your spiritual beliefs, you will find yourself challenged and stimulated by Plotinus's matchless blend of rationality and mysticism.