Never forget that we were enslaved in this country longer than we have been free. Never forget that for 250 years black people were born into chains - whole generations followed by more generations who knew nothing but chains.

You must struggle to truly remember this past in all its nuance, error, and humanity. You must resist the common urge toward the comforting narrative of divine law, toward fairy tales that imply some irrepressible justice. The enslaved were not bricks in your road, and their lives were not chapters in your redemptive history. They were people turned to fuel for the American machine. Enslavement was not destined to end, and it is wrong to claim our present circumstance - no matter how improved - as the redemption for the lives of people who never asked for the posthumous, untouchable glory of dying for their children.

I now interrupt myself with a small but crucial consideration, because now that I’ve said it several times, I realize that I am troubled by the title Slave Ship. It’s the word “slave”: a word which still strikes the ear like a lash. There are those who enslave others and there are those who are enslaved by others. But there’s no one whose essence or true description is “slave.” A person can be enslaved, can be trapped in the death-in-life known as slavery, but that is not who they are. It is something intolerable that is happening to them or that happened to them. For this reason I think that part of the original title is more accurate: Slavers Throwing Overboard the Dead and Dying.

It’s not just technology that has improved people’s lives; moral change has done so, too. In 1700, women were unable to attend university, and the feminist movement did not exist.If that well-off Brit was gay, he could not love openly; sodomy was punishable by death. In the late 1700s, three in four people globally were the victims of some form of forced labour; now less than 1 percent are. In 1700, no one lived in a democracy. Now over half the world does.

And though the future could be wonderful, it could also be terrible. To see this, look at some of the negative trends of the past and imagine a future where they are the dominant forces guiding the world. Consider that slavery had all but disappeared from France and England by the end of the twelfth century, but in the colonial era those same countries became slave traders on a massive scale. Or consider that the mid-twentieth century saw totalitarian regimes emerging even out of democracies. Or that we used scientific advances to build nuclear weapons and factory farms.