After the Berlin Wall came down I visited that city and I will never forget it. The abandoned checkpoints. The sense of excitement about the future. The knowledge that a great continent was coming together. Healing those wounds of our history is the central story of the European Union.

You don't have to be a brilliant historian to know that in Europe, messing with countries' borders, messing with their self-determination, their ability to choose their own futures, this is extremely dangerous, and that's why I think it is important to stand up to Putin.

I think the country requires fresh leadership. I do not think I can be the captain to take the country to its next destination.

Yes, America must do the right thing, but to provide moral leadership, America must do it in the right way, too.

Disease is the tax which the soul pays for the body, as the tenant pays house-rent for the use of the house.

High school is what kind of grows you into the person you are. I have great memories, good and bad, some learning experiences and some that I'll take with me the rest of my life.

My major was Fine Arts and Education thinking I would become an Art Teacher. I couldn't visualize myself as an art teacher, thinking how it wouldn't work.

Like many students, I found the drudgery of real experiments and the slowness of progress a complete shock, and at my low points I contemplated other alternative careers including study of the philosophy or sociology of science.