When 99% of people doubt your idea, you're either gravely wrong or about to make history.Scott Belsky
Doubt yourself and you doubt everything you see. Judge yourself and you see judges everywhere. But if you listen to the sound of your own voice, you can rise above doubt and judgment. And you can see forever.Nancy Lopez
A person who doubts himself is like a man who would enlist in the ranks of his enemies and bear arms against himself. He makes his failure certain by himself being the first person to be convinced of it.Alexandre Dumas
Doubt thou the stars are fire, Doubt that the sun doth move. Doubt truth to be a liar, But never doubt I love.William Shakespeare
If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things.Rene Descartes
To doubt everything or to believe everything are two equally convenient solutions; both dispense with the necessity of reflection.Henri Poincaré
The whole problem with the world is that fools and fanatics are so certain of themselves and wiser people are so full of doubts.Bertrand Russell
The problem with the world is that the intelligent people are full of doubts and the stupid ones are full of confidence.Charles Bukowski