The definition of morality is the same all over the world, and has not changed. What is moral is what is expedient for us.
What has changed, of course, are the definitions of "expedient" and "us". The history of moral evolution traces the development of the perception of expediency from an immediate view to a long-term complex definition, and the development of the perception of "us" from "our tribe" to, ultimately, "all people". Some might take it farther and say "all species".
As our definitions of "expedient" and "us" change, our specific perception of morality also changes. But what we see as "moral" is still what we see as expedient for us, no matter how thoroughly we conceal that perception in a haze of mystic gobbledygook.
Obviously, people who still live in a tribal society with a very limited concept of "us" and "them" can do things we think horrible and still think themselves eminently moral. Our ancestors did similar things at a similar stage of moral evolution. There were times when God-fearing Christian family men, exemplars of western civilization, thought it perfectly proper to burn Jews, scalp native Americans, or drop flaming gasoline on villages.
They were not "us". |