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The economist NAME_1 once wrote, “Faced with a choice between changing one's mind and proving there is no need to do so, almost everyone gets busy with the proof.” NAME_2 was even bolder: “The most difficult subjects can be explained to the most slow-witted man if he has not formed any idea of them already; but the simplest thing cannot be made clear to the most intelligent man if he is firmly persuaded that he knows already, without a shadow of doubt, what is laid before him.”

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