Lincoln sees slavery in some ways as a theft of labor. A slave is a laborer who is being denied the fruits of his labor.

Lincoln was a modernizer, so to speak. He believed in economic development. As a Whig before the war he favored what we would call infrastructure spending, government appropriation for canals, railroads, river and harbor improvements, and a tariff to protect industry. He believed in this market revolution that was sweeping across Northern society. He himself benefited from it in his own life.

I think here is the irony of American history. We don't have an established church. When you have an established church nobody takes religion as seriously as we do here. We have a free market in religion. The religious groups are competing with each other.

Freedom has been privatized - it is how you dress, what your sexual orientation is, choosing your own life. That's fine. But that is not what Thomas Jefferson was talking about.

Look, Mrs. McGillicuddy, it's not my fault your son jumped out a dorm room window on Christmas eve. I've written over fifty books as a Columbia professor, all right? You don't do that by holding hands with every at-risk undergraduate who says he's homesick, or he's turning gay, or the dog ate his term paper. I write about Lincoln, and freedom, and great ideas. I don't always have time for students. It's like Dean Martin used to say: if you want to talk, go to a priest. Hey -- what's the gun for?

Colonization was the idea that once slavery ended African-Americans should be encouraged - or required, in some people's view - required to leave the country. It's part of an attitude toward the abolition of slavery which says America should not be a slave society, but it can never be a multiracial society. You can never have free black and white people living together.

I admire Lincoln enormously and I think what's interesting about Lincoln is how he changes, it's not that he held the same view throughout his life.