I don’t think humanity just replays history, but we are the same people our ancestors were, and our descendants are going to face a lot of the same situations we do. It’s instructive to imagine how they would react, with different technologies on different worlds. That’s why I write science fiction — even though the term ‘science fiction’ excites disdain in certain persons.

The people made worse off by slavery were those who were enslaved. Their descendants would have been worse off today if born in Africa instead of America. Put differently, the terrible fate of their ancestors benefitted them.

For all men being originally equals, no one by birth could have the right to set up his own family in perpetual preference to all others forever, and thus’ himself might deserve some decent degree of honors of his cotemporaries, yet his descendants might be far too unworthy to inherit them