The arguments adduced by Knowles--his "cause of
detainder," his justification for seizing the body of Somerset--can be condensed to the single claim that "property" means material objects, the things themselves, and that "negro slaves" are no different from other "goods and chattels," that "negro slaves, brought in the course of the said trade from Africa to Virginia and Jamaica aforesaid and the said other colonies and plantations in America .