As we seem to become more and more enamored by quantifying the unquantifiable, and increasingly finding comfort in the illusory certainty of numbers, I find this quote particularly relevant: “When you don’t have any data, you have to use reason.” Richard Feynman
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I would say Feynman is biased, because of physics. There, it's much easier to reason out of problems. Real world is much more messy and only on fundamental level follows precise mathematical rules. So there are more ways to reason in physics than in a messy real life.
2/ and and you have to work accordingly with this to your best ability using reason. The context of the quote was the Challenger explosion investigation- why the concerns of the engineers went unheeded.