There are several means by which we learn about the human past. The evidence for what happened takes several forms:
- Primary evidence
- the objects people left behind
- what people wrote down
- Secondary evidence
- genetics
- human language
There are other narrow specialties as well that could be included under secondary evidence (e.g. forensics, art history), but for simplicity’s sake let’s just talk about these. By “secondary evidence,” I don’t mean that it’s less reliable. Instead, I mean that most of our knowledge of the past comes from the primary evidence, from artifacts and writing.
Each of these types of evidence is studied by a different discipline
- Archaeology is the study of physical artifacts
- History is the study of written documents
- Genetics is the study of human genes
- Historical linguistics is the study of how languages have changed over time
The genetic and linguistic evidence is especially helpful for reconstructing prehistoric migrations which are virtually impossible to trace archaeologically (with rare exceptions).
I just used the word prehistoric, so let’s define that too. Something is prehistoric if it predates the use of writing in a given area. Archaeologists can study any time period, but their work is especially valuable for understanding prehistoric cultures where there are no written records to help us know about them.
Since writing appeared in different places at different times, there is not one set time when prehistory ends and history begins. For example, 2,000 years ago writing was in use in China but not yet in Japan, so we can talk about a “prehistoric Japan” existing alongside the Han Dynasty in China for which we have written sources.
Since I am a historian and not an archaeologist, I’ll focus on the historian’s side of things in this rest of this post.
How historians specialize
There is no such thing as a historian who knows all of human history. There is such a large volume of sources, in a wide range of languages, genres, and formats, and an even larger amount of writing by historians based on those sources, that it would take hundreds of lifetimes to learn all of it well enough to do meaningful research on it all. So historians specialize.
Historians specialize along three axes:
- Region
- Period
- Theme
So for example a historian might specialize in Japanese history. But not just Japan, because that is still too big for one historian to master. So he or she chooses a period, such as Meiji (the period between 1868 and 1912). For more recent periods for which we have an abundance of source material, that would still be too broad, so then the historian chooses a theme. Examples of themes include political, economic, social (e.g. race, class, gender), or cultural (e.g. history of ideas, history of religion). So an example of a historical specialization might be labor relations in Meiji Japan. (Labor history is a type of social history.)
One should think of these axes of specialization as if they were three axes intersecting in space. The historian has to be familiar with what is going on in all three of these axes outside of their narrow field of specialization. Someone working on Meiji-era Japan will also need to have some familiarity with other periods of Japanese history (the x-axis, region), and with what was happening elsewhere in the world during the time of the Meiji (the y-axis, period). Someone who works on labor history in Japan will also need to be familiar with the broad contours of labor history in general – the major works in labor history in other regions and periods (the z-axis, theme).
What historians read
Historians read primary sources and secondary sources. Primary sources are things written by people who participated or witnessed the events they describe. They are almost never written with the idea that future people would read them. They are usually written with some short-term purpose in mind, such as letters or notes or records of transactions. Think about the writing you do in your daily life – filling out a form, writing a message to friends, making a grocery list, sending an e-mail to ask a question – your intended audience is someone alive right now (sometimes even yourself).
You never write these things thinking that people centuries in the future will read them. Because of that, while they provide evidence of what daily life is like in your time and place, they are not self-explanatory. They take for granted various expectations and conventions. When you make a grocery list, for example, you usually don’t write “grocery list” at the top of the paper and then include a paragraph explaining what grocery lists are for and what you intend to do with each item on the list. Those things are left unsaid. A future historian, living in a different culture, will need to decipher what your list means and what its purpose was in order for the people in his or her culture to understand it. That brings us to secondary sources.
How historians read, and what historians write
Secondary sources are written by historians who read a bunch of historical documents and then extrapolate from them some insight into what happened and what life was like in a past culture. Historians spend years studying a particular time and place so they can interpret the written evidence from that historical culture accurately. Moreover, historians are often interested in answering questions that people in the past did not think to address directly.
A modern historian might want to understand something about gender relations, for example, in their period of interest, but likely no one in that period explained how gender relations worked, because everyone in their culture already understood what the expectations were and so it never occurred to anyone to write them down. Or the people in the past culture might lack a concept that we have today. For example, a historian might want to understand the economics of a past community, but no one in that community thought about economics and so they never wrote anything directly about it. In these circumstances the historian must read between the lines, finding short snippets of information here and there in the written record to construct a picture that answers the question.
Because of this, the work of the historian involves not just familiarity with the primary sources, but also judgment calls about which of the myriad pieces of evidence are the most relevant to the question, which evidence should be given the most weight, and how best to interpret what the evidence is actually telling us.
The historian cannot simply report what the sources say, because the sources don’t actually say anything, at least not anything that’s relevant to what we’re trying to find out. The historian has no choice but to interpret what the sources say, in order to discover things about the past that would be relevant or interesting to us.
The work of the historian is never done. Even if a hundred other historians have written about a topic (and there are some topics that far more than a hundred historians have written about), there is always something new to say, because there is always a new way of thinking about and making sense of the primary sources.