Because I prefer National Geographic News to listening to various idiots argue about the economy, here are two short and interesting articles about the archaeology of Pre-Columbian Peru:
The first one (here) is actually a week old now, but as we've learned already, I run behind the times. Anyhow, it seems last week was the 100-year anniversary of the first excavations at Machu Picchu after its "discovery" by American historian/archaeologist Hiram Bingham (a senator AND possible inspiration for Indiana Jones, if you weren't aware). Bingham's work at the site is credited with bringing it into public focus and causing it to become the famous tourist destination it is today, and has also resulted in repatriation issues between the Peruvian government and Yale University, where most of the artifacts and remains from those early excavations wound up. Interesting stuff. The NatGeo piece linked above presents a sort of mini history on the theories about Machu Picchu's purpose, the most credible at the moment being that it functioned as a retreat for Inca royalty, a highly symbolic religious site, or some combination of the two.
This is where the whole "tolerance for ambiguity" comes in—most likely, no one is ever actually going to know why Machu Picchu exists or who lived there. There's always going to be more than one possible explanation, and which if any of them is correct is anybody's guess. Interpreting archaeological evidence is often like putting together one of those puzzles with the flat-edged pieces, where you can match up groups of pieces in an assortment of ways, but there's only one way to fit all of them together at once. In archaeology, you're missing a few pieces, so you can put together all the ones that are left, but usually in more than one way, and you can't ever be sure whether you've got it right or not.
Speaking of which...
The second article at hand went up on Thursday and is about a recent discovery of a pre-Inca tomb.
Basically, the grave of an important person was uncovered at a site that has previously yielded evidence of human sacrifice. Cool. Said important person was buried with grave goods that included big copper knives. Also cool. Big knives are apparently common in noble graves from this culture—they're a status symbol.
And yet the article's headline, the topic sentence, the photo caption, and various phrasing used throughout the article consistently claims that this person was an "executioner" or a "sacrificer". Sometimes there's a subtle qualifier like "so-and-so suggests", but other times the article here straight-up states that the grave belongs to someone who ritually killed people, as if it's a known fact.
Kids... this is what we call CIRCUMSTANTIAL EVIDENCE.
He's buried with knives at a place where women were sacrificed. Nothing about this proves that he was the sacrificer. The knives alone aren't even very good evidence to support that theory given that they're not an uncommon type of grave good for the time and place. It's an intriguing interpretation, and certainly not impossible, but it's not the only interpretation and probably not even the most likely one. National Geographic latched onto it because it will get people's attention and cause them to click on links. Maybe that's not inherently bad or wrong, but there's a way of presenting something like this that's balanced and not misleading, and then there's... well, the way they did it. If you want to inform the public, by all means do so, but draw a clear line between fact and speculation. Your interpretation of the evidence is merely that, and it really bothers me when a generally respected source like National Geographic fails to make that clear and instead gives into sensationalism.
The great poet W. H. Auden sums it up nicely (from "Archaeology"): "Knowledge may have its purposes,/ but guessing is always/ more fun than knowing."