Introduction: How Do We Decide What to Believe?
Primary and Secondary Sources
It is quite important, when evaluating historical evidence, to distinguish between primary and secondary sources. A primary source, quite simply, is information that comes from someone who was actually there, who saw or heard what happened. It also can be the actual document that was drawn up, or letters written by people carrying out actions you are studying. Secondary sources are materials developed by people who weren’t there, but who have read the primary sources. Secondary sources can be more reliable than primary sources, as the primary source may come from someone who is unwilling to tell the truth. Primary sources often have to be interpreted by scholars before they make sense. Certainly primary sources are more valuable as evidence, but they may be less valuable as a guide to truth. Consider the article on pre-revolutionary Chinese soldiers below. Would it be a primary or secondary source?
The authors of the book where this is published, of course, didn’t see the soldiers shooting at the peasants, so the book is certainly a secondary source. What about Agnes Smedley’s writing? She didn’t see the soldiers either, but simply reported what her friends had told her. So she also is a secondary source. If her friends had written about what they saw, that document would have been a primary source.