I always knew I was going to be rich. I don't think I ever doubted it for a minute. Warren Buffett
To have doubted one's own first principles is the mark of a civilized man. Oliver Wendell Holmes Jr.
One who never turned his back but marched breast forward, never doubted clouds would break, Never dreamed, though right were worsted, wrong would triumph, Held we fall to rise, are baffled to fight better, sleep to wake. Robert Browning
My guiding principle is this: Guilt is never to be doubted. Franz Kafka
The legal right of a taxpayer to decrease the amount of what otherwise would be his taxes, or altogether avoid them, by means which the law permits, cannot be doubted. George Sutherland
Who never doubted never half believed. American Proverb