The book World Thought Knowledge describes how we get to know the world and how we understand, and thereby, become a person of the world. Everyone in this world is not just a citizen of a country but also a citizen of the world. Everyone is born with the ability to think. Ignoring this ability is the same as leaving ourselves to our attitudes. But attitudes must change. In this way we can receive new knowledge. No only about the world but about ourselves. We can only learn what we do not know, yet. Anyone can gain knowledge.