"Think of US slavery in 1850, or the subjection of women. Both of these injustices could have been - and were! - defended by pointing out, quite correctly, that this situation of slaves and women had been improving throughout the preceding century. Slaves, in particular, were worked less hard, beaten and raped less frequently, better fed, and less often ripped apart from their families. So would a celebration of moral progress have been appropriate in 1850? Surely not. Slavery could have been and should have been abolished - then, if not before."