The "machineries of knowing" (Knorr Cetina 1999, p. 5) that make up finance theory's engines of inquiry are among this book's topics. More central to the book, however, is another issue. Financial economics, I argue, did more than analyze markets; it altered them. It was an "engine" in a sense not intended by Friedman: an active force transforming its environment, not a camera passively recording it.

Donald MacKenzie, An Engine, Not a Camera, loc. 64