Uncertainty that comes from knowledge (knowing what you don’t know) is different from uncertainty coming from ignorance.
I act with complete certainty. But this certainty is my own.[Ich handle mit voller Gewißheit. Aber diese Gewißheit ist meine eigene.]
Doubt is not a pleasant condition, but certainty is absurd.[Le doute n’est pas un état bien agréable, mais l’assurance est un état ridicule.]