Read the excerpt from Letters of the Late Ignatius Sancho, An African.

’Tis at the service of the afflicted,—and a much greater matter: for, in serious truth, it casts a sad shade upon the world, that so great a part of it are, and have been so long, bound in chains of darkness, and in chains of misery.

What is Sterne’s purpose in this excerpt?

to describe slavery as just one of many different types of injustices in the world
to explain that slavery is deeply rooted in society and impossible to fight
to show that slavery is a terrible practice that has brought misery to too many people
to argue that sooner or later people will do the right thing and abolish slavery