Why teach history?

I am reading Howard Fineman’s The Thirteen American Arguments (2009). His introduction points out that arguing (and arguments) rarely get a favorable review from authors like himself. Therefore, the purpose of his book is to explain that arguing has always been a vehicle for moving America toward its ideals; and that continues today.   

His first chapter describes the American argument about “Who is a person?” Reading about the answers to that question throughout American history prompted me to think about a different question. This one is related to my arguments in The Six Virtues of the Educated Person (2009).  

Whether or not you agree that Understanding, Imagination, Strength of Character, Courage, Humility and Generosity are the six virtues of the educated person, I want to know your answer to this question: From your reading of history, what conclusions do you draw about human nature? 

For example, reading the arguments over “Who is a person?” would prompt thoughtful readers to draw conclusions about human nature within the context of societies that have addressed that question. By learning how a society grants personhood, we learn about human nature more than we do about the distinctions in that society, although those may be points of interest. 

In Fineman’s chapter on American arguments about faith, he writes this about the founding fathers:

The focus of their intellectual, political and moral ambition was the world, history as it was lived, and the Enlightenment spirit of inquiry and science. (p. 64)

Evidently, our country was founded by men who drew conclusions about human nature from their study of history.

Fineman also writes:

Mixing faith and politics—souls and voting—can be uplifting, but it can be toxic, too. In the South, religion was a bulwark of slaveholding society, with elders interpreting the Old Testament view of chattel, including human chattel, literally. (pp. 65-66)

Can anybody understand that description of a historical period and not draw conclusions about human nature? This is just one example. Are social studies/history teachers asking students to draw conclusions about human nature? If not, why do we teach history?