Final answer:
The belief that Africans were inferior and lacked souls was part of a pseudo-scientific narrative, including Social Darwinism and polygenism, used to justify slavery and racial hierarchy. This narrative was dispelled by the rich history and advanced civilizations of Africa prior to European enslavement.
Step-by-step explanation:
The claim that Africans were inherently inferior and not fully human was rooted in pseudo-scientific ideologies that emerged among certain Europeans. During the late 19th and early 20th centuries, Social Darwinism suggested that non-white races had evolved up to a particular point and then ceased to evolve, while whites progressed further. This theory was often illustrated with so-called 'evolutionary chains' portraying Africans as less evolved than Europeans.
Medicine also played a role in legitimizing poor treatment of African Americans by advancing the belief that they were biologically inferior. Figures such as Thomas Jefferson and Louis Agassiz contributed to these theories, with Jefferson suggesting that Africans were predisposed to fieldwork and Agassiz advocating polygenism, which posited that different races had separate origins.
It is critical to understand the history and heritage of African Americans to counteract the 'Myths of the Negro Past,' which depicted Africa as primitive to justify slavery and propagate ideas of racial inferiority. In reality, Africa had technologically advanced and economically powerful civilizations long before European contact and the slave trade.