This was a phrase used by English philosopher Sir Francis Bacon (1561–1626) in his written attack on the widespread acceptance of the thinking of ancient philosophers such as Aristotle (384–322 B.C.) and Plato (c. 428–347 B.C.) and the founder of modern astronomy, Copernicus (1473–1543). In his 1620 work, Novum Organum, Bacon vehemently argues that human progress is held back by adherence to certain concepts, which it does not question. By hanging on to these concepts, or “idols,” humankind may proceed in error in its thinking. The double edge is that in holding to notions accepted as true, we run the danger of dismissing any new notion, a tendency Bacon characterized as arrogance. A quality that goes hand in hand with arrogance is skepticism: In adhering to that which we know, we are likely to dismiss any new ideas. To combat these obstacles, Bacon advocated a method of persistent inquiry. He believed that humans can understand nature only by carefully observing it with the help of instruments. He went on to describe scientific experimentation as an organized endeavor that should involve many scientists and which requires the support of leaders. Thus, Bacon is credited with no less than formulating modern scientific thought.