One of my all time favorites and I absolutely live my life this way:
"I think nobody should be certain of anything. If you’re certain, you’re certainly wrong because nothing deserves certainty. So one ought to hold all one’s beliefs with a certain element of doubt, and one ought to be able to act vigorously in spite of the doubt… One has in practical life to act upon probabilities, and what I should look to philosophy to do is to encourage people to act with vigor without complete certainty." -Bertrand Russell
I chose the integrity one from those listed.