My post about scientific ideas which might be obsolete in 50 years led S. to speculate on which actions or activities that we now consider moral (i.e., positively good) could be considered immoral in the future.
Here are her comments:
Many of the actions of 19th-century America fell into this category. The first that comes into mind is the cultivation of the wilderness. Slavery was a very minor issue in the Texian revolution against Mexico. Apparently many Americans, even in the non-slave states, considered that slavery was necessary for productive use of Texas, and that this admitted evil was less than the evil of leaving the land fallow. A recent echo of this world-view was the pro-Zionist argument from my elementary-school days: that the Israelis made better use of the land, "making the desert bloom", so they should have it. (Aside: I was not convinced by this. I doubt it was my own independent thought, but rather that in New Zealand, which was underdeveloped and liked it that way, the argument didn't ring true to my teachers.).
A second is the carting off of the American Indians to boarding schools, punishing them for speaking their own language, etc.... (Aside: I imagine we [English] would have punished Gaelic and Welsh speakers in British schools at the same time if we had got around to it.) I tend to believe that the main impulse from which this action was drawn was the desire to give the children a better life in a better civilization. The judgment that one civilization is better than another has gone from universal and unapologetic to partial and often apologetic. I suppose that I hope that eventually it will be commonplace to consider all cultures different but equal, because I hope that in the future the only ghastly places will be in history. If those who attempted to civilize ghastly, or even lesser, places are then condemned, it is probably a small (although sad) price to pay.
A third, older one, is the mortification of the flesh. Often when I luxuriate in my warm and exactly soft-enough bed, I wonder to what extent that sensation would have been counted as - if not exactly evil - at least an unworthy fleshly distraction (as in "the world, the flesh, and the devil"). People now wreck their bodies to become thin, to become athletes, or through overindulgence: you would be sent straight to a psychiatrist if you wanted to wreck your body for the glory of God. (The punishment of heretics to save their souls is obviously related).
Looking at the three activities, I notice that they are all rather hard work, and related to achieving a state of perfection that we no longer believe in. I can therefore hope that working too hard and eating too healthily will be equally frowned on in the future, and that for true and timeless morality I should relax my standards in those areas.