Questions about Aztecs and blood sacrifice

I've read that the Aztecs performed over 50,000 blood sacrifices a year. How do we know? How did they pick them? Wouldn't this have a detrimental effect on their population growth? What proof do we have other than the drawings and how do we know how many were performed each year? If we have the bodies, how do we know they were killed ritually?

Just wondering...

 

Interesting questions, some nearly unanswerable.

Aside from drawings/carvings, they have indeed found thousands of remains near, beneath, and inside important religious/ritual sites of the Aztecs, namely Teotihuacan and environs, though whether it was the Aztecs themselves who conducted these rituals is somewhat up for argument. It may have been the mysterious Toltecs, who actually built those structures.

The evidence for ritual sacrifice has been determined by the conditions of the remains, the particular injuries seemingly sustained, and also apparent tools of ritual (knives, hammer-like things) found with the bodies. Also, in Tenochtitlan, some of the temples were actually constructed of human skulls and can still be seen today in Mexico City...though that, also, isn't hard evidence of particular ritual sacrifice.

There have been similar findings among the Mayan ruins of Mexico...along with carvings, and in the case of the Maya written records, it is obvious that there was, indeed, a culture of ritual sacrifice in pre-Columbian Mexico.

I for one am not surprised really, considering that there are many Schools of Magic (Priests and Magicians may have been one and the same in pre-Columbian Mexico) which encourage and believe in Sacrifice to perform their more powerful ritual....in the Modern Day, even.