Sun’s Disposition on This & Future Days

I remember back in college we were talking about the Aztecs. One of the coolest things, that was not to cool for the person who did it, was bloodletting. I guess this is only done by people that held clout. Instead of fighting and killing someone like the lowly ppl did, these people would take a vine, with orange, pierce their tongue, and run the vine through that hole in their tongue. 

Seriously, how did they come up with that? Where do rituals come from?
“Well we always did it this way?”  Or

“we are going to make some laws, and your going to shut up because I make it laws.”