Published sources, just like unpublished letters, diaries, or government records, have to be examined and interrogated critically. Authors have their perspectives and agendas, they often do not have access to a complete set of the evidence, and they make mistakes. So when we find a published source we have to treat it as a theory and compare it to the other evidence to check for accuracy and bias. A description of an event is simply a piece of evidence until it is partnered with other pieces of evidence that begin to convince us that the event did indeed happen in the way that it was written.
While we have aimed to concisely reproduce brief but important portions of the books included on this site, sometimes it was necessary to include longer excerpts. In some cases, these excerpts are critical to understanding a unique set of ideas or a singular description of events. In others, the texts are included so that you may compare them – in all their fullness – to descriptions made by others, or made by the writer at a different time.