From the Greek philo, meaning “love of,” and sophia, meaning “wisdom,” philosophy is literally a love of wisdom. In practice, it is the pursuit of understanding the human condition—how, why, and what it means to exist or to be. Philosophers use methods such as observation and questioning to discern the truth. Philosophy is traditionally divided between Eastern thought and Western thought. Further, Western thought consists of five branches: metaphysics (concerned with the nature of the universe or of reality); logic (the laws of reasoning); epistemology (the nature of knowledge and the process by which knowledge is gained); ethics (the moral values or rules that influence human conduct); and aesthetics (the nature of beauty or the criteria for art).