"Readers should not forget what is as hard to appreciate today in the case of slave trading as it was over a hundred years ago when Gomer Williams wrote his book - that both were legitimate endeavours in the eyes of domestic and emerging international law, and, more important, neither was viewed as in any way immoral: before the late eighteenth century, slave trading and privateering were seen as indistinguishable from trading in Baltic timber or Canadian furs." David Eltis, from the new introduction, 2004.