In the book Uncle Tom's Cabin What justification does Alfred, Augustine’s twin brother, give for hundreds of slaves to run his plantation?

This quote from Ch 19 should help:

"no, he stands, high and haughty, on that good old respectable ground, the right of the strongest; and he says, and I think quite sensibly, that the American planter is 'only doing, in another form, what the English aristocracy and capitalists are doing by the lower classes;' that is, I take it, appropriating them, body and bone, soul and spirit, to their use and convenience. "