The problem with archaeology is that it rarely happens that the ancients wrote an explanation of what they left behind. If only King Priam had written a note “this place was sacked by Achaeans”, we would not have been forced to listen to boring debates about the presence of LH IIIc1 sherds in a Troy VIh context. It’s typical for the ancients that they didn’t bother to consider our questions.
So how do we interpret those finds? Basically, the main tool for archaeologists is to look for parallels in comparable societies. To explain why megalithic monuments were built, some archaeologists have been looking at similar monuments on Java, where dolmens have been built quite recently; the explanation offered in the recent past, was projected back on the Stone Age. A second tool is the study of texts: those knives we find in a tomb in, say, northern England, must belong to a surgeon, because we have a picture of those instruments on a small mausoleum in Ostia, where an inscription says that the dead owner was a physician. The written word explains a silent object.
The problem is that not every problem can be solved with these two tools. But here, another principle comes in handy: if you do not know what it is, it has something to do with religion. So, an unusual building in Qumran becomes a monastery (in fact, it turned out to be a pottery factory). A set of terracotta figurines resembling women becomes a temple of the Great Goddess (in fact, a Mycenaean toy shop).
This principle is known as the First Law of Archaeology – and yes, that is sarcasm.