First Law of Archaeology: ironical name for a tendency among archaeologists to explain things they do not understand as religious.
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 sad but true, but the ancients didn’t bother to consider the questions we'd like to ask.
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, archaeologists have been looking at similar monuments on Java, where dolmens have been built more 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 the silent object.
However, 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. Bones on an unexpected place become evidence for a ceremony. A set of terracotta figurines resembling women becomes a temple of the Great Goddess.
This principle is known as the First Law of Archaeology – and yes, that is sarcasm.