The Dao De Jing exists on the border between poetry and philosophy, embracing both mythos and logos. Its poetic form can stand alone, but it is enriched when its timeless ideas are analyzed and explained through careful scholarship. For example: "He who knows others is knowledgeable. He who knows himself is wise." These words resemble Socrates' account of his own quest in Plato's Apology. Ancient philosophy, both in China and in Greece, places self-knowledge at the center of the search for wisdom. Contemporary philosophers are often misled about this way of thinking, because the self has been detached from external things and separated from nature and society. The wisdom of China and of Europe unites human existence and nature.