A single part of physics occupies the lives of many men, and often leaves them dying in uncertainty.
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.