Isn't this ultimately about the right to withdraw one's labour?
The slave has to work, whether he likes it or not. Slavery denies to the enslaved their basic human rights. The slave is treated by the master like an unfeeling production unit, is kept and maintained while productive.
The master in effect owns and controls the slave through what he can force the slave to do by means of the laws of the land <1> and by force of economic necessity.
The free man may withdraw his labour. He enters into a voluntary agreement with someone else in which he agrees to carry out some specified work in return for a specified amount of pay. If there is disagreement between them he may freely withdraw his labour. This is a most essential right, the right of every citizen, of every worker, to associate with others and withdraw his labour, to go on strike.
Admittedly, the slave analogy is OTT, but the point is valid?
2p