[blam]

Thanks.

I never understood the need to sacrifice the life of something to the gods/spirits. Notice that the sacrifice is usually something that hasn't a choice specifically, little kids in Peru.

[Fedora]

The last chapter of Volume 2 of E.B. Tylor's Primitive Culture has a section on the animistic belief system underlying sacrificial ritual which is a good introduction to the subject. Here is a more recent article summarizing various anthropological research and theories:

"Sacrifice", from The Encyclopedia of Religion