Why creativity without insight is doomed to fail

I had a professor in Sociology 101 sophomore year whose name I can't remember, but whose class still stays with me.He had absurdly high standards and was ruthless when it came to evaluating how much of the material you understood. His tests were impossibly hard; he would have failed some of them. When asked why they were so difficult, he said, to paraphrase, "I could make the test easier and you'd all get 4.0s, but I wouldn't know if you knew the material. I'd rather give you hard tests, grade