Slave (n.) is "bad" in Euripides' view because he sees everything from the viewpoint of the stomach.
Slave (n.) lost half his excellence the day of his slavery, Homer says — because he lost the public realm where excellence can show.
Slave (n.) of antiquity served chiefly to carry the burden of consumption in the household, not to produce for society.
The Slave (n.) was despised by Plato for not killing himself rather than serve; once staying alive became a holy duty, that contempt could not survive.
A Slave (n.) still had a place: his labor was needed, used and exploited — more than the abstract nakedness of being human and nothing but human.
Slave (n.) suffered a fate worse than death in Greek eyes: a metamorphosis of man into something like a tame animal.