“One must verify or expel his doubts, and convert them into the certainty of YES or NO.” – Thomas Carlyle

Thomas (the disciple of Jesus) did that: “My Lord and My God.” – John 20

Don’t waste life in doubts and fears; spend yourself on the work before you, well assured that the right performance of this hour’s duties will be the best preparation for the hours and ages that will follow it.
– Ralph Waldo Emerson

The deplorable mania of doubt exhausts me. I doubt about everything, even my doubts.
Gustave Flaubert

The beginning of wisdom is found in doubting; by doubting we come to the question, and by seeking we may come upon the truth.
Pierre Abelard