"First, people have already heard the arguments against the practice. The case against slavery didn't emerge in a blinding moment of moral clarity, for instance; it had been around for centuries.Appiah then goes on to suggest four possible sets of contemporary practices that our children or grandchildren may well find abhorrent: the prison system (he has his eyes especially on the US situation); industrial meat production; the institutionalisation of the elderly; and our ecologically destructive lifestyles.
"Second, defenders of the custom tend not to offer moral counterarguments but instead invoke tradition, human nature or necessity. (As in, "We've always had slaves, and how could we grow cotton without them?")
"And third, supporters engage in what one might call strategic ignorance, avoiding truths that might force them to face the evils in which they're complicit. Those who ate the sugar or wore the cotton that the slaves grew simply didn't think about what made those goods possible. That's why abolitionists sought to direct attention toward the conditions of the Middle Passage, through detailed illustrations of slave ships and horrifying stories of the suffering below decks."
I briefly considered this question myself towards the end of this post on morality as distraction, specifically focussing on the issue of whether the church is offering hostages to fortune through our current practices and attitudes.
Are there more examples you can think of that meet his three criteria? In your estimation, which one(s) is (are) most likely to see future shifts in judgement?