For some people, history lessons are clear.

For some, history lessons are ambiguous.

For some, history lessons are depressing.

These cartoons capture differences among historians, teachers, and the rest of us about whether or not there are lessons that must be heeded when decisionmakers seek solutions to pressing problems.

No clear lessons, however, can be drawn from the past because then and now are different in significant ways. Take the second cartoon where the man in the center assumes that the other two are agreeing with him when they have completely opposite analogies in mind. The notion of obvious lessons derived from the past assumes that, for example, France and Britain caving into Hitler’s demands over Czechoslovakia in the 1938 Munich Pact was similar to the U.S. government sending troops to Vietnam to prevent Southeast Asian nations falling like dominoes to communism and, again, similar to President George W. Bush…