 .slavery itself, considered as such in its essential nature, is not at all contrary to the natural and divine law, and there can be several just titles of slavery and these are referred to by approved theologians and commentators of the sacred canons.For the sort of ownership which a slave-owner has over a slave is understood as nothing other than the perpetual right of disposing of the work of a slave for one's own benefit - services which it is right for one human being to provide for another.