This document discusses the importance and effects of truth-telling and lying. It begins by outlining the long history and importance placed on truth in human civilization from ancient codes like the Code of Hammurabi to modern oaths. It then defines truth-telling as communicating information one believes to be true, and outlines its importance for making informed decisions, demonstrating respect, building trust, and enabling democracy. The document defines a lie as intentionally deceiving through untrue information with the goal of misleading. It discusses how lies harm both the person lied to by depriving them of control and potentially causing wrong decisions, as well as harming the liar through needing to remember lies and risking loss of credibility if exposed.