From Marginal Revolution. This is a link to an article that links to another article, but both are worth your time:
But why shouldn’t our standards change over time? Most of the people in the 1850s who thought slavery was an abomination would have rejected the idea of inter-racial marriage. Wife beating wasn’t considered a violent crime in just the very recent past. What racism and sexism mean has changed over time. Are these examples of concept creep or progress? I’d argue progress but the blue dot experiment of Levari et al. suggests that if even objective concepts morph under prevalence inducement then subjective concepts surely will. The issue then is not to prevent progress but to recognize it and not be fooled into thinking that progress hasn’t been made just because our identifications have changed.
The world is becoming a better place. Progress.