… is from page 73 of Deirdre McCloskey’s 1994 volume, Knowledge and Persuasion in Economics :
An economist looking at the business world is like a critic looking at the art world. Economists and other human scientists can reflect intelligently on present conditions and can tell useful stories about the past. These produce wisdom, which produce broad, conditional “predictions.” Some are obvious; some require an economist; but in equilibrium, after the $20 bills have been picked up, none is a machine for achieving fame or riches. The study of the human sciences can produce wisdom, routine predictions. It cannot produce profitable prediction and godlike control.