Who said “Uncertainty is the refuge of hope.”?

“Hesitation increases in relation to risk in equal proportion to age.”

“The quest for certainty blocks the search for meaning. Uncertainty is the very condition to impel man to unfold his powers.”

“The grand perhaps! We look on helplessly, there the old misgivings, crooked questions are.”

“Uncertainty and mystery are energies of life. Don't let them scare you unduly, for they keep boredom at bay and spark creativity.”

“Will localizes us; thought universalizes us.”

“Cleverness is serviceable for everything, sufficient for nothing.”

“Our duty is to be useful, not according to our desires, but according to our powers.”

“An error is the more dangerous in proportion to the degree of truth which it contains.”

“To do easily what is difficult for others is the mark of talent. To do what is impossible for talent is the mark of genius.”

“Without passion man is a mere latent force and possibility, like the flint which awaits the shock of the iron before it can give forth its spark.”