"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
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