ABSTRACT
For knowledge that all adults have, one book may be as good a source of information as another. If you do not know where Rome is located, you may look it up in any atlas or encyclopedia and feel reasonably confident that you have the answer without having to follow up references to see how the compilers found out.1 For knowledge that is less certain-and in dealing with the ancient world, precious little is really certain-one cannot necessarily rely on just any book’s information. Even such straightforward questions as when, or even whether, a particular person lived may turn out to be debatable.Whenever it makes a difference whether what we think is true or false, we have to find out what the sources are on which we base our knowledge.
