I will now let Dave speak for himself:
….Take the example of a single book, Plato’s Republic. The book was written in something like the 4th century BCE. Until the discovery of the Nag Hammadi library in Egypt in the 1945 the very earliest manuscript of The Republic that was known to exist was from around 895 CE. The version of The Republic in the Nag Hammadi library dates from something like 325 CE. Assuming that the text that came down to the Founding Fathers was derived from the 895 manuscript (a very bad assumption-it wasn’t), the book had been preserved for a half millennium by Christian scribes for Christian purposes.This would be a good point for a digression-within-a-digression about the Arab copyists who preserved many works of classical antiquity but that would be too big a digression. Suffice it to say that these copyists took copies that had been preserved by Christians and preserved them themselves for their own, presumably Muslim, reasons.So The Republic has a history something like this. We don’t have a single copy of the work from Plato’s time. For six or seven hundred years it was copied by Greek and Roman scribes for reasons we can only guess at. It was then copied for between a half and a full millennium by Christian, Jewish, and Arab scribes for Christian, Jewish, and Muslim reasons.That is the history of every single work from classical antiquity that survived until the time of the founding of our republic. We have, essentially, no idea of the entire body of work produced by the ancients. What was known of classical antiquity at the time of the founding our republic consisted of the buildings that still survived that they had built (often highly modified for Christian use), works of art and other artifacts, classical writings that had been preserved by Christian, Jewish, and Muslim scribes for their own purposes and that, presumably, furthered their agenda, and accounts of classical antiquity from Christian and Jewish writers.That’s it.
History is an empirical profession based on standards of evidence – in part. It is also an art of crafting a narrative that can effectively communicate the meaning of the evidence of an event that is known to exist. Leopold von Ranke, one of the founders of the modern historical method, admonished his students that history should explain “wie es eigentlich gewesen ist” ( “Tell it how it really was” or “how it actually has been”) and eschew grand theories in seeking causation. These are difficult objectives to balance.
Historians are prisoners of their primary sources. Without them they are theorists or mere speculators. Too few, as with ancient history, and the historian is engaged in the same sort of guesswork as archaeologists and paleontologists or they are reduced to ideological theorizing, something historians are supposed to hold as suspect and as fit only for political scientists.
Too many sources, as with any modern presidential administration, and the sheer number makes it difficult to find critical evidence or draw upon a defensibly representative sample. Ronald Reagan supposedly signed one million documents in his eight years in the White House. True or not, the figure would represent a fraction of what his administration generated. Many documents of great importance are nonetheless not important enough at the time to cross the desk of the President of the United States.
The need to craft a narrative, imposes other restraints. There is no “history” unless the results of a historian’s work are disseminated and understood, challenged and defended. Narrative works require the formating of historical events as a story and while this is reasonable in most instances, some periods of crisis are products of chance or a series of small acts that while unrelated, happen to intersect. Imposing a strong narrative frame on these situations is misleading but without the “story” there is no hook attractive enough to secure the attention of the general audience.
This is not to say, as Henry Ford did, that “history is bunk” but rather we need to be aware of the practical limitations under which historians labor. While history is not sociology or philosophy, it is not to be confused with physics.