To know evil For to know evil, for them, was to know it not by pure intelligence by by experience. Charles Williams, The Mind of the Maker evil
A minimum size to fish There is the famous story by Eddington about some people who went fishing in the sea with a net. Upon examining the size of the fish they had caught, they decided there was a minimum size to the fish in the sea! Their conclusion arose from the tool used and not from reality. Richard Hamming, The Art of Doing Science and Engineering: Learning to Learn Every Tool Shapes the Task tools