Our American past always speaks to us with two voices: the voice of the past, and the voice of the present. We are always asking two quite different questions. Historians reading the words of John Winthrop usually ask, What did they mean to him? Citizens ask, What do they mean to us? Historians are trained to seek the original meaning; all of us want to know the present meaning.

The great obstacle to discovering the shape of the earth, the continents, and the oceans was not ignorance, but the illusion of knowledge.

The mind is a vagrant thing.... Thinking is not analogous to a person working in a laboratory who invents something on company time.

The hero created himself; the celebrity is created by the media.

The most promising words ever written on the maps of human knowledge are terra incognita, unknown territory.

Time makes heroes but dissolves celebrities.

I write to discover what I think. After all, the bars aren't open that early.