Lewis Spence,
The Mythologies of Ancient Mexico and Peru
“ But although this exalted philosophy had been adopted by the fierce and uncultured Aztecs, it had become so obscured by the introduction of cruel and inhuman rites and customs as to be almost no longer recognisable as the pure faith of the race they had succeeded in the land. The germ and core of the Aztec religion was the idea of the constant necessity of propitiating the gods by means of human sacrifice, and to this aspect of their religion we will return later. ”
