Policy makers use past experience and history to think about current and potential problems and to explain policies and problems to others. Decision makers may be overly influenced by significant personally-experienced events that loom so large in their eyes that details and related relevant information may pale in comparison. Deficiencies in content or logic may ultimately not matter in the quality or political efficacy of a lesson, but need to be assessed along with the context and effect of the lesson to establish a complete assessment of that lesson and the role the lesson played in the decision making process. Learning can be said to have taken place with regard to examination of a historically based lesson if that experience leads to change or altered policies. This requires that a baseline be established on what relevant policy makers believed about the world prior to the event. Decision makers do not use history all that poorly when the political context and the actual content of lessons are taken into account. Decision makers do pay attention to current context and that context, not the past, heavily influences the uses of the past. The evidence for the ways to look at lessons from the past are largely drawn from the case of Pearl Harbor and its influence on U.S. post-war defense policy. A list of 28 references is included. (PPB)