Ever since the beginnings of modern science in the 17th century, natural philosophers and scientists have used clockwork machinery as a metaphor to describe the universe and the natural world. The machinery model generally makes one think of something rigid, rote, constrained, something that ticks and whirs and grinds along without changing. However, hidden within this centuries-old clockwork-machinery metaphor is a tradition of people who have understood artificial machinery, and nature, very differently: as restless, responsive, and dynamic. These renegades include the English doctors and physiologists William Harvey and Thomas Willis, who minutely studied the mechanisms of generation and the brain and nervous system, respectively; the German philosopher Leibniz, who first described living things as “organisms,” and who said living organisms resembled clocks in their “restlessness”; and the French naturalist Lamarck who was the first to present a theory of what we now call evolution. All compared living beings to artificial machinery but meant an active, responsive, restless sort of machinery.