Adam Smith on Slavery

I generally think of Adam Smith as explaining what was happening in the 18th century economy, not as a social reformer.  But there's this, highlighted in a recent paper.

There is not a negro from the coast of Africa who does not, in this respect, possess a degree of magnanimity which the soul of his sordid master is too often scarce capable of conceiving. Fortune never exerted more cruelly her empire over mankind, than when she subjected those nations of heroes to the refuse of the jails of Europe, to wretches who possess the virtues neither of the countries which they come from, nor of those which they go to, and whose levity, brutality, and baseness, so justly expose them to the contempt of the vanquished. (TMS 206–7.9)