Civil Disagreement

There is a marvelous quotation from the inimitable William Raspberry that I had only half-remembered and could cite only imperfectly. My brother came up with a more precise quotation from which I have found, so far, one decent source. Here is what I have now:

After writing more than 5,000 opinion columns, Mr. Raspberry said in a speech at the University of Virginia in 2006, he had learned two important lessons.
The first, he said, “is that in virtually every public controversy, most thoughtful people secretly believe both sides.”
“The second, which has kept my confidence from turning into arrogance, is that it is entirely possible for you to disagree with me without being, on that account, either a scoundrel or a fool.”

I would like to have a primary source (the speech itself) rather than this secondary source.


Little help?