“We cannot think first and act afterwards. From the moment of birth we are immersed in action and can only guide it by taking thought.”

“The aim of science is to seek the simplest explanations of complex facts. We are apt to fall into the error of thinking that the facts are simple because simplicity is the goal of our quest. The guiding motto in the life of every natural philosopher should be, 'Seek simplicity and distrust it.”

“It is a profoundly erroneous truism that we should cultivate the habit of thinking of what we are doing. The precise opposite is the case. Civilization advances by extending the number of important operations which we can perform without thinking about them.”

“Civilization advances by extending the number of important operations which we can perform without thinking of them. ”

“We think in generalities, but we live in detail. To make the past live, we must perceive it in detail in addition to thinking of it in generalities.”

“Intelligence is quickness to apprehend as distinct from ability, which is capacity to act wisely on the thing apprehended.”

“Error is the price we pay for progress.”