What is the fine-grained topic of the following text: The commerce therefore, which was begun in the primitive ages of the world, by classing them with the brutal species, and by habituating the mind to consider the terms of brute and slave as synonimous, soon caused them to be viewed in a low and despicable light, and as greatly inferiour to the human species. Only return the topic.
Dehumanization and inferiority of slaves in early commerce.