“Darwin didn’t consider himself a quick or highly analytical thinker. His memory was poor, and he couldn’t follow long mathematical arguments. Nevertheless, Darwin felt that he made up for those shortcomings with a crucial strength: his urge to figure out how reality worked. Ever since he could remember, he had been driven to make sense of the world around him. He followed what he called a “golden rule” to fight against motivated reasoning:
. . . whenever a published fact, a new observation or thought came across me, which was opposed to my general results, to make a memorandum of it without fail and at once; for I had found by experience that such facts and thoughts were far more apt to escape from the memory than favourable ones.
Therefore, even though the peacock’s tail made him anxious, Darwin couldn’t stop puzzling over it. How could it possibly be consistent with natural selection?
Within a few years, he had figured out the beginnings of a compelling answer.”