The document discusses the nature of history and how historians investigate the past. It states that history is an investigation or inquiry into past events using various types of sources as evidence. Historians use tools from different fields like science, literature, and economics to help solve mysteries of the ancient past, similar to how detectives solve crimes. When investigating the past, historians have to piece together information from artifacts, writings, oral histories, images, and other sources to get a full picture since the evidence is sometimes incomplete.