According to Aristotle, natural slaves' main features include being pieces of property, tools for actions, and belonging to others.
[4]It is not advantageous for one to be held in slavery who is not a natural slave, Aristotle contends, claiming that such a condition is sustained solely by force and results in enmity.
According to Darrell Dobbs, there is a "general consensus that the formulation of Aristotle's account of slavery is riddled with inconsistency and incoherence.
[9] In April 1550, Las Casas and Juan Ginés de Sepúlveda met in Spain for a debate on the rationalization of native American enslavement and its morality based on Aristotle's idea of natural slavery.
"[10] Las Casas countered that Aristotle's definition of the "barbarian" and the natural slave did not apply to the Indians, who were fully capable of reason and should be brought to Christianity without force or coercion.