Solution:While Justifying slavery Aristotle says that from the hour of birth some men are marked out for subjection and other for rule, that man of capacity, farsight, self reliance and the life of virtue are intend by nature to work with their mind, that they have capacity to discharge intelligently own duties only.
Aristotle did not say that they are machine without having it slaves develops virtue of reason and courage, master can make him free. Slavery was the institution practiced in ancient Greece there used to be two categories of slaves. (A) Natural slave → Slave by Nature (B) Slave by Law → Prisoners of war