What two "big philosophical questions"

does Jefferson's ownership of slave raise?

Thomas Jefferson, a man of great contradictions. He was one of the Founding Fathers of the United States but he was the owner of slaves.

One question would be: Are really all humans equal by nature? Men's natural-born rights of life, freedom were only applicable to white people and not to black slaves.

Second question: Can you hold that men can improve their destiny by their own actions but keep slaves who are deprived of the realization of their own will at the same time?