great question. here, the Slave is a commodity in the flesh. when I say Slave I am particularly thinking of new world (chattel) slavery, which was structured along racial lines. these racial sciences were already established however materially accumulated through this conjuncture https://twitter.com/theofficialjrod/status/1279905143576645632

these racial sciences established black flesh, under the political economic conjuncture of the new world, as the sign of commodity thereby rendering African bodies fungible and accumulated through gratuitous violence, natal alienation, and general dishonor.

as Marxism will tell you, the difference between a slave and a worker is that the slave owns none of its labour power and none of the means of production whereas the workers owns varying degrees of each but never all. however, this assumes that the slave is a human subject.