Why did Polybius consider political and military experience important for historians?

Polybius believed that history should be pragmatikē historia—a practical, didactic discipline focused on political and military matters rather than mere entertainment or myth-making. For him, political and military experience were essential components of a historian's toolkit for several reasons:1

• Instruction over Sensationalism: Polybius argued that the goal of history is to benefit serious students through the record of real facts and speeches, contrasting this with the "tragic" style of predecessors who sought to thrill readers through sensationalism or probable fictions.1
• Practical Utility: He maintained that the study of history provides the soundest education for political activity and serves as the best way to learn how to endure the "vicissitudes of fortune" by reflecting on the disasters of others.1
• Reliability of Evidence: Polybius defined the historian’s task as the collation of documents, geographical knowledge, and political experience. He viewed firsthand experience and the questioning of witnesses as vital, noting that relying on anything else resulted in "hearsay at one remove," which he considered an insufficient foundation for making accurate historical judgments.2

By integrating these experiences, a historian could provide a synoptic, universal view capable of analyzing complex events like the rise of Rome.1