The students in my Ancient Cities course recently encountered an insightful but challenging reading, a chapter in a book dense with that most hated of academic discourses: theory. Just say “theory” at someone – and I don’t mean only undergrads – and their eyes will glaze over as they visibly fight the urge to check their Twitter notifications.

Unless they’re like me. I love theory. Theory is my favorite thing in all of archaeology to teach. Understanding theory means deciphering the tangled logic puzzle of “how do we know what we know.” Understanding theory means making clear – and then criticizing – all the unstated thought processes that archaeologists go through in making sense of our information.

For example, take a string of numbers: 17351. You can observe the numbers written here, but if someone made you stop reading this post right now and asked you what those numbers meant, you’d probably say “who knows.”

But what if you kept reading and saw that I added some symbols in with the numbers: 17 x 3 = 51. Suddenly you can say something about the numbers. They’re a multiplication problem. There’s a relationship that makes the first three numbers equal to the second two numbers. The first two numbers should be considered as a unit, the third number is a unit on its own, and the last two numbers are also a unit.

We’ve applied theory to the numbers. Now we can say what they mean.

Archaeological theory works with artifacts like mathematical operations in a string of numbers. Theory structures the relationships among artifacts and other archaeological data, allowing archaeologists to understand how they interact. Without theory – and the application of theory, which we call method – archaeologists would endlessly collect old things without actually adding to our knowledge of the past. We would dig up artifacts, document architecture, maybe even identify some campfires and postholes, but we wouldn’t know what any of it meant. It would just be a string of numbers… er… artifacts.

The early days of European curiosity about the past were full of “strings” of artifacts – in reality, these were drawers, boxes, cabinets, and rooms that housed jumbled assemblages of ancient objects. Antiquaries^{1} of the late Renaissance and the Age of Enlightenment collected these objects – sometimes digging into barrows or other monuments to find them – and documented the existence of ancient sites. But they found themselves trying and failing to describe relationships among the sites and artifacts. They hadn’t developed any archaeological theory, so they couldn’t interpret what their finds meant. The problem was so acute that the Danish antiquary Rasmus Nyerup (1759-1829)^{2} complained that “Everything which has come down to us from heathendom is wrapped in a thick fog.”^{3}

Fortunately, antiquaries began developing foundational theory that allowed them to start organizing finds. Ideas like the Three Age System – which was proposed in 1816 and divided European prehistory^{4} into Stone, Bronze, and Iron Ages based on the primary materials used for tools – allowed antiquaries to begin recognizing relationships among their materials. Other types of theory like the concepts of typology and seriation – the idea that artifacts that looked similar probably came from similar time periods and that these time periods could be arranged chronologically – moved the study of the past from antiquarian collecting into the budding discipline of archaeological explanation.

Great, you say. Antiquaries formulated theory, applied it to artifacts, established archaeology, and now we know what the past means. But not so fast – let’s return to that string of numbers. What if instead of making it a multiplication problem, I use different symbols: |1 x 7 – 3 – 5| = 1. This way of interpreting the numbers is equally consistent and so equally valid as the first.

Archaeology works like this, too. Often, multiple ways of applying theory give us internally consistent understandings of the past. What if I asked you for an ecological explanation of why I wore my orange sweater today? You might say I wore it because the weather turned cold and I wanted to stay warm. But what if I asked you for a postcolonial interpretation of why I wore my sweater? Then you might say it relates to my position within a historic system that channels global resources toward the west, making it possible for me to own a (probably excessive) number of warm sweaters. Both these ways of applying theory to my sweater produce perspectives that are true and useful for understanding my experience.

Now don’t get me wrong: the past is not all relative. Archaeologists can demonstrate that many ways of understanding the past are straight-up false, and it is *not* the case that every interpretation is as good as any another. For example, what if I ordered my numbers like this: 1 + 7 + 3 + 5 = 1. That’s simply wrong. Unlike my first two proposals, this interpretation of the numbers does not show a logical relationship. Or what if you claimed that I wore my orange sweater because I always wear orange on Wednesdays. Examining my previous Wednesday wardrobe choices would show you this is not an accurate explanation (I mean, last Wednesday I wore plaid!).

Even though not all understandings of the past are true, it *is* true that the past was as rich and varied as human life today, so it shouldn’t surprise us that multiple ways of understanding the past can be accurate and provide insight. And thanks to a long history of archaeological thinking, we’re not at a loss to distinguish the good explanations from the bad. Robust archaeological theory provides the tools we need to tell the difference between rigorous interpretations of the past and ones that don’t stand up to scrutiny.

- The term “antiquary” refers generally to a person who studies the past and is especially used to describe people who collected ancient artifacts and documented sites in the period before archaeology became a field.
- (2009). Nyerup, Rasmus. In
*The Concise Oxford Dictionary of Archaeology*, 2nd edition (online). eISBN: 9780191727139 DOI: 10.1093/acref/9780199534043.001.0001 - Page 51 in Fagan, B. M., and Durani, N. (2016).
*A Brief History of Archaeology. Classical Times to the Twenty-First Century*, 2^{nd}edition. London and New York: Routledge. ISBN: 9781138657076 - The Three Age System was specifically applied to Danish prehistory when it was first proposed, but it was found to be broadly useful and adopted for European prehistory in general.