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What about in all the armies of the world? And all the sacrifices that were made to the Sun God in the ancient cultures of mesoamerica, where were their morals?

Actually, the concept of sacrifice is an excellent manifestation of morality. And it has survived till our times, just in a different form. But the concept is still the same: accept some suffering now so that there is less suffering in the future. We do it everyday.

The thing one can imagine situations where killing and stealing is justified. Yet there can be extracted some meta-rules which are shared by all cultures across all human history.

Killing was poor word choice. Murder is universally accepted as wrong, and youd be hard pressed to find societies (not individuals) which have no problem with stealing. All societies have scenarios in which they justify the taking of life.